1use crate::{
2 elements::ElementBox,
3 executor::{self, Task},
4 keymap::{self, Keystroke},
5 platform::{self, CursorStyle, Platform, PromptLevel, WindowOptions},
6 presenter::Presenter,
7 util::{post_inc, timeout},
8 AssetCache, AssetSource, ClipboardItem, FontCache, PathPromptOptions, TextLayoutCache,
9};
10use anyhow::{anyhow, Result};
11use keymap::MatchResult;
12use parking_lot::Mutex;
13use platform::Event;
14use postage::{mpsc, oneshot, sink::Sink as _, stream::Stream as _};
15use smol::prelude::*;
16use std::{
17 any::{type_name, Any, TypeId},
18 cell::RefCell,
19 collections::{hash_map::Entry, BTreeMap, HashMap, HashSet, VecDeque},
20 fmt::{self, Debug},
21 hash::{Hash, Hasher},
22 marker::PhantomData,
23 mem,
24 ops::{Deref, DerefMut},
25 path::{Path, PathBuf},
26 pin::Pin,
27 rc::{self, Rc},
28 sync::{
29 atomic::{AtomicUsize, Ordering::SeqCst},
30 Arc, Weak,
31 },
32 time::Duration,
33};
34
35pub trait Entity: 'static {
36 type Event;
37
38 fn release(&mut self, _: &mut MutableAppContext) {}
39 fn app_will_quit(
40 &mut self,
41 _: &mut MutableAppContext,
42 ) -> Option<Pin<Box<dyn 'static + Future<Output = ()>>>> {
43 None
44 }
45}
46
47pub trait View: Entity + Sized {
48 fn ui_name() -> &'static str;
49 fn render(&mut self, cx: &mut RenderContext<'_, Self>) -> ElementBox;
50 fn on_focus(&mut self, _: &mut ViewContext<Self>) {}
51 fn on_blur(&mut self, _: &mut ViewContext<Self>) {}
52 fn keymap_context(&self, _: &AppContext) -> keymap::Context {
53 Self::default_keymap_context()
54 }
55 fn default_keymap_context() -> keymap::Context {
56 let mut cx = keymap::Context::default();
57 cx.set.insert(Self::ui_name().into());
58 cx
59 }
60}
61
62pub trait ReadModel {
63 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T;
64}
65
66pub trait ReadModelWith {
67 fn read_model_with<E: Entity, T>(
68 &self,
69 handle: &ModelHandle<E>,
70 read: &mut dyn FnMut(&E, &AppContext) -> T,
71 ) -> T;
72}
73
74pub trait UpdateModel {
75 fn update_model<T: Entity, O>(
76 &mut self,
77 handle: &ModelHandle<T>,
78 update: &mut dyn FnMut(&mut T, &mut ModelContext<T>) -> O,
79 ) -> O;
80}
81
82pub trait UpgradeModelHandle {
83 fn upgrade_model_handle<T: Entity>(
84 &self,
85 handle: &WeakModelHandle<T>,
86 ) -> Option<ModelHandle<T>>;
87
88 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle>;
89}
90
91pub trait UpgradeViewHandle {
92 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>>;
93}
94
95pub trait ReadView {
96 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T;
97}
98
99pub trait ReadViewWith {
100 fn read_view_with<V, T>(
101 &self,
102 handle: &ViewHandle<V>,
103 read: &mut dyn FnMut(&V, &AppContext) -> T,
104 ) -> T
105 where
106 V: View;
107}
108
109pub trait UpdateView {
110 fn update_view<T, S>(
111 &mut self,
112 handle: &ViewHandle<T>,
113 update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
114 ) -> S
115 where
116 T: View;
117}
118
119pub trait Action: 'static + AnyAction {
120 type Argument: 'static + Clone;
121}
122
123pub trait AnyAction {
124 fn id(&self) -> TypeId;
125 fn name(&self) -> &'static str;
126 fn as_any(&self) -> &dyn Any;
127 fn boxed_clone(&self) -> Box<dyn AnyAction>;
128 fn boxed_clone_as_any(&self) -> Box<dyn Any>;
129}
130
131#[macro_export]
132macro_rules! action {
133 ($name:ident, $arg:ty) => {
134 #[derive(Clone)]
135 pub struct $name(pub $arg);
136
137 impl $crate::Action for $name {
138 type Argument = $arg;
139 }
140
141 impl $crate::AnyAction for $name {
142 fn id(&self) -> std::any::TypeId {
143 std::any::TypeId::of::<$name>()
144 }
145
146 fn name(&self) -> &'static str {
147 stringify!($name)
148 }
149
150 fn as_any(&self) -> &dyn std::any::Any {
151 self
152 }
153
154 fn boxed_clone(&self) -> Box<dyn $crate::AnyAction> {
155 Box::new(self.clone())
156 }
157
158 fn boxed_clone_as_any(&self) -> Box<dyn std::any::Any> {
159 Box::new(self.clone())
160 }
161 }
162 };
163
164 ($name:ident) => {
165 #[derive(Clone, Debug, Eq, PartialEq)]
166 pub struct $name;
167
168 impl $crate::Action for $name {
169 type Argument = ();
170 }
171
172 impl $crate::AnyAction for $name {
173 fn id(&self) -> std::any::TypeId {
174 std::any::TypeId::of::<$name>()
175 }
176
177 fn name(&self) -> &'static str {
178 stringify!($name)
179 }
180
181 fn as_any(&self) -> &dyn std::any::Any {
182 self
183 }
184
185 fn boxed_clone(&self) -> Box<dyn $crate::AnyAction> {
186 Box::new(self.clone())
187 }
188
189 fn boxed_clone_as_any(&self) -> Box<dyn std::any::Any> {
190 Box::new(self.clone())
191 }
192 }
193 };
194}
195
196pub struct Menu<'a> {
197 pub name: &'a str,
198 pub items: Vec<MenuItem<'a>>,
199}
200
201pub enum MenuItem<'a> {
202 Action {
203 name: &'a str,
204 keystroke: Option<&'a str>,
205 action: Box<dyn AnyAction>,
206 },
207 Separator,
208}
209
210#[derive(Clone)]
211pub struct App(Rc<RefCell<MutableAppContext>>);
212
213#[derive(Clone)]
214pub struct AsyncAppContext(Rc<RefCell<MutableAppContext>>);
215
216#[derive(Clone)]
217pub struct TestAppContext {
218 cx: Rc<RefCell<MutableAppContext>>,
219 foreground_platform: Rc<platform::test::ForegroundPlatform>,
220}
221
222impl App {
223 pub fn new(asset_source: impl AssetSource) -> Result<Self> {
224 let platform = platform::current::platform();
225 let foreground_platform = platform::current::foreground_platform();
226 let foreground = Rc::new(executor::Foreground::platform(platform.dispatcher())?);
227 let app = Self(Rc::new(RefCell::new(MutableAppContext::new(
228 foreground,
229 Arc::new(executor::Background::new()),
230 platform.clone(),
231 foreground_platform.clone(),
232 Arc::new(FontCache::new(platform.fonts())),
233 asset_source,
234 ))));
235
236 foreground_platform.on_quit(Box::new({
237 let cx = app.0.clone();
238 move || {
239 cx.borrow_mut().quit();
240 }
241 }));
242 foreground_platform.on_menu_command(Box::new({
243 let cx = app.0.clone();
244 move |action| {
245 let mut cx = cx.borrow_mut();
246 if let Some(key_window_id) = cx.cx.platform.key_window_id() {
247 if let Some((presenter, _)) =
248 cx.presenters_and_platform_windows.get(&key_window_id)
249 {
250 let presenter = presenter.clone();
251 let path = presenter.borrow().dispatch_path(cx.as_ref());
252 cx.dispatch_action_any(key_window_id, &path, action);
253 } else {
254 cx.dispatch_global_action_any(action);
255 }
256 } else {
257 cx.dispatch_global_action_any(action);
258 }
259 }
260 }));
261
262 app.0.borrow_mut().weak_self = Some(Rc::downgrade(&app.0));
263 Ok(app)
264 }
265
266 pub fn on_become_active<F>(self, mut callback: F) -> Self
267 where
268 F: 'static + FnMut(&mut MutableAppContext),
269 {
270 let cx = self.0.clone();
271 self.0
272 .borrow_mut()
273 .foreground_platform
274 .on_become_active(Box::new(move || callback(&mut *cx.borrow_mut())));
275 self
276 }
277
278 pub fn on_resign_active<F>(self, mut callback: F) -> Self
279 where
280 F: 'static + FnMut(&mut MutableAppContext),
281 {
282 let cx = self.0.clone();
283 self.0
284 .borrow_mut()
285 .foreground_platform
286 .on_resign_active(Box::new(move || callback(&mut *cx.borrow_mut())));
287 self
288 }
289
290 pub fn on_quit<F>(self, mut callback: F) -> Self
291 where
292 F: 'static + FnMut(&mut MutableAppContext),
293 {
294 let cx = self.0.clone();
295 self.0
296 .borrow_mut()
297 .foreground_platform
298 .on_quit(Box::new(move || callback(&mut *cx.borrow_mut())));
299 self
300 }
301
302 pub fn on_event<F>(self, mut callback: F) -> Self
303 where
304 F: 'static + FnMut(Event, &mut MutableAppContext) -> bool,
305 {
306 let cx = self.0.clone();
307 self.0
308 .borrow_mut()
309 .foreground_platform
310 .on_event(Box::new(move |event| {
311 callback(event, &mut *cx.borrow_mut())
312 }));
313 self
314 }
315
316 pub fn on_open_files<F>(self, mut callback: F) -> Self
317 where
318 F: 'static + FnMut(Vec<PathBuf>, &mut MutableAppContext),
319 {
320 let cx = self.0.clone();
321 self.0
322 .borrow_mut()
323 .foreground_platform
324 .on_open_files(Box::new(move |paths| {
325 callback(paths, &mut *cx.borrow_mut())
326 }));
327 self
328 }
329
330 pub fn run<F>(self, on_finish_launching: F)
331 where
332 F: 'static + FnOnce(&mut MutableAppContext),
333 {
334 let platform = self.0.borrow().foreground_platform.clone();
335 platform.run(Box::new(move || {
336 let mut cx = self.0.borrow_mut();
337 let cx = &mut *cx;
338 crate::views::init(cx);
339 on_finish_launching(cx);
340 }))
341 }
342
343 pub fn platform(&self) -> Arc<dyn Platform> {
344 self.0.borrow().platform()
345 }
346
347 pub fn font_cache(&self) -> Arc<FontCache> {
348 self.0.borrow().cx.font_cache.clone()
349 }
350
351 fn update<T, F: FnOnce(&mut MutableAppContext) -> T>(&mut self, callback: F) -> T {
352 let mut state = self.0.borrow_mut();
353 let result = state.update(callback);
354 state.pending_notifications.clear();
355 result
356 }
357}
358
359impl TestAppContext {
360 pub fn new(
361 foreground_platform: Rc<platform::test::ForegroundPlatform>,
362 platform: Arc<dyn Platform>,
363 foreground: Rc<executor::Foreground>,
364 background: Arc<executor::Background>,
365 font_cache: Arc<FontCache>,
366 first_entity_id: usize,
367 ) -> Self {
368 let mut cx = MutableAppContext::new(
369 foreground.clone(),
370 background,
371 platform,
372 foreground_platform.clone(),
373 font_cache,
374 (),
375 );
376 cx.next_entity_id = first_entity_id;
377 let cx = TestAppContext {
378 cx: Rc::new(RefCell::new(cx)),
379 foreground_platform,
380 };
381 cx.cx.borrow_mut().weak_self = Some(Rc::downgrade(&cx.cx));
382 cx
383 }
384
385 pub fn dispatch_action<A: Action>(
386 &self,
387 window_id: usize,
388 responder_chain: Vec<usize>,
389 action: A,
390 ) {
391 self.cx
392 .borrow_mut()
393 .dispatch_action_any(window_id, &responder_chain, &action);
394 }
395
396 pub fn dispatch_global_action<A: Action>(&self, action: A) {
397 self.cx.borrow_mut().dispatch_global_action(action);
398 }
399
400 pub fn dispatch_keystroke(
401 &self,
402 window_id: usize,
403 responder_chain: Vec<usize>,
404 keystroke: &Keystroke,
405 ) -> Result<bool> {
406 let mut state = self.cx.borrow_mut();
407 state.dispatch_keystroke(window_id, responder_chain, keystroke)
408 }
409
410 pub fn add_model<T, F>(&mut self, build_model: F) -> ModelHandle<T>
411 where
412 T: Entity,
413 F: FnOnce(&mut ModelContext<T>) -> T,
414 {
415 self.cx.borrow_mut().add_model(build_model)
416 }
417
418 pub fn add_window<T, F>(&mut self, build_root_view: F) -> (usize, ViewHandle<T>)
419 where
420 T: View,
421 F: FnOnce(&mut ViewContext<T>) -> T,
422 {
423 self.cx
424 .borrow_mut()
425 .add_window(Default::default(), build_root_view)
426 }
427
428 pub fn window_ids(&self) -> Vec<usize> {
429 self.cx.borrow().window_ids().collect()
430 }
431
432 pub fn root_view<T: View>(&self, window_id: usize) -> Option<ViewHandle<T>> {
433 self.cx.borrow().root_view(window_id)
434 }
435
436 pub fn add_view<T, F>(&mut self, window_id: usize, build_view: F) -> ViewHandle<T>
437 where
438 T: View,
439 F: FnOnce(&mut ViewContext<T>) -> T,
440 {
441 self.cx.borrow_mut().add_view(window_id, build_view)
442 }
443
444 pub fn add_option_view<T, F>(
445 &mut self,
446 window_id: usize,
447 build_view: F,
448 ) -> Option<ViewHandle<T>>
449 where
450 T: View,
451 F: FnOnce(&mut ViewContext<T>) -> Option<T>,
452 {
453 self.cx.borrow_mut().add_option_view(window_id, build_view)
454 }
455
456 pub fn read<T, F: FnOnce(&AppContext) -> T>(&self, callback: F) -> T {
457 callback(self.cx.borrow().as_ref())
458 }
459
460 pub fn update<T, F: FnOnce(&mut MutableAppContext) -> T>(&mut self, callback: F) -> T {
461 let mut state = self.cx.borrow_mut();
462 // Don't increment pending flushes in order to effects to be flushed before the callback
463 // completes, which is helpful in tests.
464 let result = callback(&mut *state);
465 // Flush effects after the callback just in case there are any. This can happen in edge
466 // cases such as the closure dropping handles.
467 state.flush_effects();
468 result
469 }
470
471 pub fn to_async(&self) -> AsyncAppContext {
472 AsyncAppContext(self.cx.clone())
473 }
474
475 pub fn font_cache(&self) -> Arc<FontCache> {
476 self.cx.borrow().cx.font_cache.clone()
477 }
478
479 pub fn foreground_platform(&self) -> Rc<platform::test::ForegroundPlatform> {
480 self.foreground_platform.clone()
481 }
482
483 pub fn platform(&self) -> Arc<dyn platform::Platform> {
484 self.cx.borrow().cx.platform.clone()
485 }
486
487 pub fn foreground(&self) -> Rc<executor::Foreground> {
488 self.cx.borrow().foreground().clone()
489 }
490
491 pub fn background(&self) -> Arc<executor::Background> {
492 self.cx.borrow().background().clone()
493 }
494
495 pub fn simulate_new_path_selection(&self, result: impl FnOnce(PathBuf) -> Option<PathBuf>) {
496 self.foreground_platform.simulate_new_path_selection(result);
497 }
498
499 pub fn did_prompt_for_new_path(&self) -> bool {
500 self.foreground_platform.as_ref().did_prompt_for_new_path()
501 }
502
503 pub fn simulate_prompt_answer(&self, window_id: usize, answer: usize) {
504 let mut state = self.cx.borrow_mut();
505 let (_, window) = state
506 .presenters_and_platform_windows
507 .get_mut(&window_id)
508 .unwrap();
509 let test_window = window
510 .as_any_mut()
511 .downcast_mut::<platform::test::Window>()
512 .unwrap();
513 let mut done_tx = test_window
514 .last_prompt
515 .take()
516 .expect("prompt was not called");
517 let _ = done_tx.try_send(answer);
518 }
519}
520
521impl AsyncAppContext {
522 pub fn spawn<F, Fut, T>(&self, f: F) -> Task<T>
523 where
524 F: FnOnce(AsyncAppContext) -> Fut,
525 Fut: 'static + Future<Output = T>,
526 T: 'static,
527 {
528 self.0.borrow().foreground.spawn(f(self.clone()))
529 }
530
531 pub fn read<T, F: FnOnce(&AppContext) -> T>(&mut self, callback: F) -> T {
532 callback(self.0.borrow().as_ref())
533 }
534
535 pub fn update<T, F: FnOnce(&mut MutableAppContext) -> T>(&mut self, callback: F) -> T {
536 self.0.borrow_mut().update(callback)
537 }
538
539 pub fn add_model<T, F>(&mut self, build_model: F) -> ModelHandle<T>
540 where
541 T: Entity,
542 F: FnOnce(&mut ModelContext<T>) -> T,
543 {
544 self.update(|cx| cx.add_model(build_model))
545 }
546
547 pub fn platform(&self) -> Arc<dyn Platform> {
548 self.0.borrow().platform()
549 }
550
551 pub fn foreground(&self) -> Rc<executor::Foreground> {
552 self.0.borrow().foreground.clone()
553 }
554
555 pub fn background(&self) -> Arc<executor::Background> {
556 self.0.borrow().cx.background.clone()
557 }
558}
559
560impl UpdateModel for AsyncAppContext {
561 fn update_model<E: Entity, O>(
562 &mut self,
563 handle: &ModelHandle<E>,
564 update: &mut dyn FnMut(&mut E, &mut ModelContext<E>) -> O,
565 ) -> O {
566 self.0.borrow_mut().update_model(handle, update)
567 }
568}
569
570impl UpgradeModelHandle for AsyncAppContext {
571 fn upgrade_model_handle<T: Entity>(
572 &self,
573 handle: &WeakModelHandle<T>,
574 ) -> Option<ModelHandle<T>> {
575 self.0.borrow().upgrade_model_handle(handle)
576 }
577
578 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
579 self.0.borrow().upgrade_any_model_handle(handle)
580 }
581}
582
583impl UpgradeViewHandle for AsyncAppContext {
584 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
585 self.0.borrow_mut().upgrade_view_handle(handle)
586 }
587}
588
589impl ReadModelWith for AsyncAppContext {
590 fn read_model_with<E: Entity, T>(
591 &self,
592 handle: &ModelHandle<E>,
593 read: &mut dyn FnMut(&E, &AppContext) -> T,
594 ) -> T {
595 let cx = self.0.borrow();
596 let cx = cx.as_ref();
597 read(handle.read(cx), cx)
598 }
599}
600
601impl UpdateView for AsyncAppContext {
602 fn update_view<T, S>(
603 &mut self,
604 handle: &ViewHandle<T>,
605 update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
606 ) -> S
607 where
608 T: View,
609 {
610 self.0.borrow_mut().update_view(handle, update)
611 }
612}
613
614impl ReadViewWith for AsyncAppContext {
615 fn read_view_with<V, T>(
616 &self,
617 handle: &ViewHandle<V>,
618 read: &mut dyn FnMut(&V, &AppContext) -> T,
619 ) -> T
620 where
621 V: View,
622 {
623 let cx = self.0.borrow();
624 let cx = cx.as_ref();
625 read(handle.read(cx), cx)
626 }
627}
628
629impl UpdateModel for TestAppContext {
630 fn update_model<T: Entity, O>(
631 &mut self,
632 handle: &ModelHandle<T>,
633 update: &mut dyn FnMut(&mut T, &mut ModelContext<T>) -> O,
634 ) -> O {
635 self.cx.borrow_mut().update_model(handle, update)
636 }
637}
638
639impl ReadModelWith for TestAppContext {
640 fn read_model_with<E: Entity, T>(
641 &self,
642 handle: &ModelHandle<E>,
643 read: &mut dyn FnMut(&E, &AppContext) -> T,
644 ) -> T {
645 let cx = self.cx.borrow();
646 let cx = cx.as_ref();
647 read(handle.read(cx), cx)
648 }
649}
650
651impl UpdateView for TestAppContext {
652 fn update_view<T, S>(
653 &mut self,
654 handle: &ViewHandle<T>,
655 update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
656 ) -> S
657 where
658 T: View,
659 {
660 self.cx.borrow_mut().update_view(handle, update)
661 }
662}
663
664impl ReadViewWith for TestAppContext {
665 fn read_view_with<V, T>(
666 &self,
667 handle: &ViewHandle<V>,
668 read: &mut dyn FnMut(&V, &AppContext) -> T,
669 ) -> T
670 where
671 V: View,
672 {
673 let cx = self.cx.borrow();
674 let cx = cx.as_ref();
675 read(handle.read(cx), cx)
676 }
677}
678
679type ActionCallback =
680 dyn FnMut(&mut dyn AnyView, &dyn AnyAction, &mut MutableAppContext, usize, usize) -> bool;
681type GlobalActionCallback = dyn FnMut(&dyn AnyAction, &mut MutableAppContext);
682
683type SubscriptionCallback = Box<dyn FnMut(&dyn Any, &mut MutableAppContext) -> bool>;
684type ObservationCallback = Box<dyn FnMut(&mut MutableAppContext) -> bool>;
685type ReleaseObservationCallback = Box<dyn FnMut(&mut MutableAppContext)>;
686
687pub struct MutableAppContext {
688 weak_self: Option<rc::Weak<RefCell<Self>>>,
689 foreground_platform: Rc<dyn platform::ForegroundPlatform>,
690 assets: Arc<AssetCache>,
691 cx: AppContext,
692 actions: HashMap<TypeId, HashMap<TypeId, Vec<Box<ActionCallback>>>>,
693 global_actions: HashMap<TypeId, Box<GlobalActionCallback>>,
694 keystroke_matcher: keymap::Matcher,
695 next_entity_id: usize,
696 next_window_id: usize,
697 next_subscription_id: usize,
698 frame_count: usize,
699 subscriptions: Arc<Mutex<HashMap<usize, BTreeMap<usize, SubscriptionCallback>>>>,
700 observations: Arc<Mutex<HashMap<usize, BTreeMap<usize, ObservationCallback>>>>,
701 release_observations: Arc<Mutex<HashMap<usize, BTreeMap<usize, ReleaseObservationCallback>>>>,
702 presenters_and_platform_windows:
703 HashMap<usize, (Rc<RefCell<Presenter>>, Box<dyn platform::Window>)>,
704 debug_elements_callbacks: HashMap<usize, Box<dyn Fn(&AppContext) -> crate::json::Value>>,
705 foreground: Rc<executor::Foreground>,
706 pending_effects: VecDeque<Effect>,
707 pending_notifications: HashSet<usize>,
708 pending_flushes: usize,
709 flushing_effects: bool,
710 next_cursor_style_handle_id: Arc<AtomicUsize>,
711}
712
713impl MutableAppContext {
714 fn new(
715 foreground: Rc<executor::Foreground>,
716 background: Arc<executor::Background>,
717 platform: Arc<dyn platform::Platform>,
718 foreground_platform: Rc<dyn platform::ForegroundPlatform>,
719 font_cache: Arc<FontCache>,
720 asset_source: impl AssetSource,
721 // entity_drop_tx:
722 ) -> Self {
723 Self {
724 weak_self: None,
725 foreground_platform,
726 assets: Arc::new(AssetCache::new(asset_source)),
727 cx: AppContext {
728 models: Default::default(),
729 views: Default::default(),
730 windows: Default::default(),
731 element_states: Default::default(),
732 ref_counts: Arc::new(Mutex::new(RefCounts::default())),
733 background,
734 font_cache,
735 platform,
736 },
737 actions: HashMap::new(),
738 global_actions: HashMap::new(),
739 keystroke_matcher: keymap::Matcher::default(),
740 next_entity_id: 0,
741 next_window_id: 0,
742 next_subscription_id: 0,
743 frame_count: 0,
744 subscriptions: Default::default(),
745 observations: Default::default(),
746 release_observations: Default::default(),
747 presenters_and_platform_windows: HashMap::new(),
748 debug_elements_callbacks: HashMap::new(),
749 foreground,
750 pending_effects: VecDeque::new(),
751 pending_notifications: HashSet::new(),
752 pending_flushes: 0,
753 flushing_effects: false,
754 next_cursor_style_handle_id: Default::default(),
755 }
756 }
757
758 pub fn upgrade(&self) -> App {
759 App(self.weak_self.as_ref().unwrap().upgrade().unwrap())
760 }
761
762 pub fn quit(&mut self) {
763 let mut futures = Vec::new();
764 for model_id in self.cx.models.keys().copied().collect::<Vec<_>>() {
765 let mut model = self.cx.models.remove(&model_id).unwrap();
766 futures.extend(model.app_will_quit(self));
767 self.cx.models.insert(model_id, model);
768 }
769
770 for view_id in self.cx.views.keys().copied().collect::<Vec<_>>() {
771 let mut view = self.cx.views.remove(&view_id).unwrap();
772 futures.extend(view.app_will_quit(self));
773 self.cx.views.insert(view_id, view);
774 }
775
776 self.remove_all_windows();
777
778 let futures = futures::future::join_all(futures);
779 if self
780 .background
781 .block_with_timeout(Duration::from_millis(100), futures)
782 .is_err()
783 {
784 log::error!("timed out waiting on app_will_quit");
785 }
786 }
787
788 fn remove_all_windows(&mut self) {
789 for (window_id, _) in self.cx.windows.drain() {
790 self.presenters_and_platform_windows.remove(&window_id);
791 }
792 self.remove_dropped_entities();
793 }
794
795 pub fn platform(&self) -> Arc<dyn platform::Platform> {
796 self.cx.platform.clone()
797 }
798
799 pub fn font_cache(&self) -> &Arc<FontCache> {
800 &self.cx.font_cache
801 }
802
803 pub fn foreground(&self) -> &Rc<executor::Foreground> {
804 &self.foreground
805 }
806
807 pub fn background(&self) -> &Arc<executor::Background> {
808 &self.cx.background
809 }
810
811 pub fn on_debug_elements<F>(&mut self, window_id: usize, callback: F)
812 where
813 F: 'static + Fn(&AppContext) -> crate::json::Value,
814 {
815 self.debug_elements_callbacks
816 .insert(window_id, Box::new(callback));
817 }
818
819 pub fn debug_elements(&self, window_id: usize) -> Option<crate::json::Value> {
820 self.debug_elements_callbacks
821 .get(&window_id)
822 .map(|debug_elements| debug_elements(&self.cx))
823 }
824
825 pub fn add_action<A, V, F>(&mut self, mut handler: F)
826 where
827 A: Action,
828 V: View,
829 F: 'static + FnMut(&mut V, &A, &mut ViewContext<V>),
830 {
831 let handler = Box::new(
832 move |view: &mut dyn AnyView,
833 action: &dyn AnyAction,
834 cx: &mut MutableAppContext,
835 window_id: usize,
836 view_id: usize| {
837 let action = action.as_any().downcast_ref().unwrap();
838 let mut cx = ViewContext::new(cx, window_id, view_id);
839 handler(
840 view.as_any_mut()
841 .downcast_mut()
842 .expect("downcast is type safe"),
843 action,
844 &mut cx,
845 );
846 cx.halt_action_dispatch
847 },
848 );
849
850 self.actions
851 .entry(TypeId::of::<V>())
852 .or_default()
853 .entry(TypeId::of::<A>())
854 .or_default()
855 .push(handler);
856 }
857
858 pub fn add_async_action<A, V, F>(&mut self, mut handler: F)
859 where
860 A: Action,
861 V: View,
862 F: 'static + FnMut(&mut V, &A, &mut ViewContext<V>) -> Option<Task<Result<()>>>,
863 {
864 self.add_action(move |view, action, cx| {
865 handler(view, action, cx).map(|task| task.detach_and_log_err(cx));
866 })
867 }
868
869 pub fn add_global_action<A, F>(&mut self, mut handler: F)
870 where
871 A: Action,
872 F: 'static + FnMut(&A, &mut MutableAppContext),
873 {
874 let handler = Box::new(move |action: &dyn AnyAction, cx: &mut MutableAppContext| {
875 let action = action.as_any().downcast_ref().unwrap();
876 handler(action, cx);
877 });
878
879 if self
880 .global_actions
881 .insert(TypeId::of::<A>(), handler)
882 .is_some()
883 {
884 panic!("registered multiple global handlers for the same action type");
885 }
886 }
887
888 pub fn window_ids(&self) -> impl Iterator<Item = usize> + '_ {
889 self.cx.windows.keys().cloned()
890 }
891
892 pub fn activate_window(&self, window_id: usize) {
893 if let Some((_, window)) = self.presenters_and_platform_windows.get(&window_id) {
894 window.activate()
895 }
896 }
897
898 pub fn root_view<T: View>(&self, window_id: usize) -> Option<ViewHandle<T>> {
899 self.cx
900 .windows
901 .get(&window_id)
902 .and_then(|window| window.root_view.clone().downcast::<T>())
903 }
904
905 pub fn root_view_id(&self, window_id: usize) -> Option<usize> {
906 self.cx.root_view_id(window_id)
907 }
908
909 pub fn focused_view_id(&self, window_id: usize) -> Option<usize> {
910 self.cx.focused_view_id(window_id)
911 }
912
913 pub fn render_view(
914 &mut self,
915 window_id: usize,
916 view_id: usize,
917 titlebar_height: f32,
918 refreshing: bool,
919 ) -> Result<ElementBox> {
920 let mut view = self
921 .cx
922 .views
923 .remove(&(window_id, view_id))
924 .ok_or(anyhow!("view not found"))?;
925 let element = view.render(window_id, view_id, titlebar_height, refreshing, self);
926 self.cx.views.insert((window_id, view_id), view);
927 Ok(element)
928 }
929
930 pub fn render_views(
931 &mut self,
932 window_id: usize,
933 titlebar_height: f32,
934 ) -> HashMap<usize, ElementBox> {
935 self.start_frame();
936 let view_ids = self
937 .views
938 .keys()
939 .filter_map(|(win_id, view_id)| {
940 if *win_id == window_id {
941 Some(*view_id)
942 } else {
943 None
944 }
945 })
946 .collect::<Vec<_>>();
947 view_ids
948 .into_iter()
949 .map(|view_id| {
950 (
951 view_id,
952 self.render_view(window_id, view_id, titlebar_height, false)
953 .unwrap(),
954 )
955 })
956 .collect()
957 }
958
959 pub(crate) fn start_frame(&mut self) {
960 self.frame_count += 1;
961 }
962
963 pub fn update<T, F: FnOnce(&mut Self) -> T>(&mut self, callback: F) -> T {
964 self.pending_flushes += 1;
965 let result = callback(self);
966 self.flush_effects();
967 result
968 }
969
970 pub fn set_menus(&mut self, menus: Vec<Menu>) {
971 self.foreground_platform.set_menus(menus);
972 }
973
974 fn prompt(
975 &self,
976 window_id: usize,
977 level: PromptLevel,
978 msg: &str,
979 answers: &[&str],
980 ) -> oneshot::Receiver<usize> {
981 let (_, window) = &self.presenters_and_platform_windows[&window_id];
982 window.prompt(level, msg, answers)
983 }
984
985 pub fn prompt_for_paths(
986 &self,
987 options: PathPromptOptions,
988 ) -> oneshot::Receiver<Option<Vec<PathBuf>>> {
989 self.foreground_platform.prompt_for_paths(options)
990 }
991
992 pub fn prompt_for_new_path(&self, directory: &Path) -> oneshot::Receiver<Option<PathBuf>> {
993 self.foreground_platform.prompt_for_new_path(directory)
994 }
995
996 pub fn subscribe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
997 where
998 E: Entity,
999 E::Event: 'static,
1000 H: Handle<E>,
1001 F: 'static + FnMut(H, &E::Event, &mut Self),
1002 {
1003 self.subscribe_internal(handle, move |handle, event, cx| {
1004 callback(handle, event, cx);
1005 true
1006 })
1007 }
1008
1009 pub fn observe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
1010 where
1011 E: Entity,
1012 E::Event: 'static,
1013 H: Handle<E>,
1014 F: 'static + FnMut(H, &mut Self),
1015 {
1016 self.observe_internal(handle, move |handle, cx| {
1017 callback(handle, cx);
1018 true
1019 })
1020 }
1021
1022 pub fn subscribe_internal<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
1023 where
1024 E: Entity,
1025 E::Event: 'static,
1026 H: Handle<E>,
1027 F: 'static + FnMut(H, &E::Event, &mut Self) -> bool,
1028 {
1029 let id = post_inc(&mut self.next_subscription_id);
1030 let emitter = handle.downgrade();
1031 self.subscriptions
1032 .lock()
1033 .entry(handle.id())
1034 .or_default()
1035 .insert(
1036 id,
1037 Box::new(move |payload, cx| {
1038 if let Some(emitter) = H::upgrade_from(&emitter, cx.as_ref()) {
1039 let payload = payload.downcast_ref().expect("downcast is type safe");
1040 callback(emitter, payload, cx)
1041 } else {
1042 false
1043 }
1044 }),
1045 );
1046 Subscription::Subscription {
1047 id,
1048 entity_id: handle.id(),
1049 subscriptions: Some(Arc::downgrade(&self.subscriptions)),
1050 }
1051 }
1052
1053 fn observe_internal<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
1054 where
1055 E: Entity,
1056 E::Event: 'static,
1057 H: Handle<E>,
1058 F: 'static + FnMut(H, &mut Self) -> bool,
1059 {
1060 let id = post_inc(&mut self.next_subscription_id);
1061 let observed = handle.downgrade();
1062 self.observations
1063 .lock()
1064 .entry(handle.id())
1065 .or_default()
1066 .insert(
1067 id,
1068 Box::new(move |cx| {
1069 if let Some(observed) = H::upgrade_from(&observed, cx) {
1070 callback(observed, cx)
1071 } else {
1072 false
1073 }
1074 }),
1075 );
1076 Subscription::Observation {
1077 id,
1078 entity_id: handle.id(),
1079 observations: Some(Arc::downgrade(&self.observations)),
1080 }
1081 }
1082
1083 pub fn observe_release<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
1084 where
1085 E: Entity,
1086 E::Event: 'static,
1087 H: Handle<E>,
1088 F: 'static + FnMut(&mut Self),
1089 {
1090 let id = post_inc(&mut self.next_subscription_id);
1091 self.release_observations
1092 .lock()
1093 .entry(handle.id())
1094 .or_default()
1095 .insert(id, Box::new(move |cx| callback(cx)));
1096 Subscription::ReleaseObservation {
1097 id,
1098 entity_id: handle.id(),
1099 observations: Some(Arc::downgrade(&self.release_observations)),
1100 }
1101 }
1102
1103 fn defer(&mut self, callback: Box<dyn FnOnce(&mut MutableAppContext)>) {
1104 self.pending_effects.push_back(Effect::Deferred(callback))
1105 }
1106
1107 pub(crate) fn notify_model(&mut self, model_id: usize) {
1108 if self.pending_notifications.insert(model_id) {
1109 self.pending_effects
1110 .push_back(Effect::ModelNotification { model_id });
1111 }
1112 }
1113
1114 pub(crate) fn notify_view(&mut self, window_id: usize, view_id: usize) {
1115 if self.pending_notifications.insert(view_id) {
1116 self.pending_effects
1117 .push_back(Effect::ViewNotification { window_id, view_id });
1118 }
1119 }
1120
1121 pub fn dispatch_action<A: Action>(
1122 &mut self,
1123 window_id: usize,
1124 responder_chain: Vec<usize>,
1125 action: &A,
1126 ) {
1127 self.dispatch_action_any(window_id, &responder_chain, action);
1128 }
1129
1130 pub(crate) fn dispatch_action_any(
1131 &mut self,
1132 window_id: usize,
1133 path: &[usize],
1134 action: &dyn AnyAction,
1135 ) -> bool {
1136 self.update(|this| {
1137 let mut halted_dispatch = false;
1138 for view_id in path.iter().rev() {
1139 if let Some(mut view) = this.cx.views.remove(&(window_id, *view_id)) {
1140 let type_id = view.as_any().type_id();
1141
1142 if let Some((name, mut handlers)) = this
1143 .actions
1144 .get_mut(&type_id)
1145 .and_then(|h| h.remove_entry(&action.id()))
1146 {
1147 for handler in handlers.iter_mut().rev() {
1148 let halt_dispatch =
1149 handler(view.as_mut(), action, this, window_id, *view_id);
1150 if halt_dispatch {
1151 halted_dispatch = true;
1152 break;
1153 }
1154 }
1155 this.actions
1156 .get_mut(&type_id)
1157 .unwrap()
1158 .insert(name, handlers);
1159 }
1160
1161 this.cx.views.insert((window_id, *view_id), view);
1162
1163 if halted_dispatch {
1164 break;
1165 }
1166 }
1167 }
1168
1169 if !halted_dispatch {
1170 halted_dispatch = this.dispatch_global_action_any(action);
1171 }
1172 halted_dispatch
1173 })
1174 }
1175
1176 pub fn dispatch_global_action<A: Action>(&mut self, action: A) {
1177 self.dispatch_global_action_any(&action);
1178 }
1179
1180 fn dispatch_global_action_any(&mut self, action: &dyn AnyAction) -> bool {
1181 self.update(|this| {
1182 if let Some((name, mut handler)) = this.global_actions.remove_entry(&action.id()) {
1183 handler(action, this);
1184 this.global_actions.insert(name, handler);
1185 true
1186 } else {
1187 false
1188 }
1189 })
1190 }
1191
1192 pub fn add_bindings<T: IntoIterator<Item = keymap::Binding>>(&mut self, bindings: T) {
1193 self.keystroke_matcher.add_bindings(bindings);
1194 }
1195
1196 pub fn dispatch_keystroke(
1197 &mut self,
1198 window_id: usize,
1199 responder_chain: Vec<usize>,
1200 keystroke: &Keystroke,
1201 ) -> Result<bool> {
1202 let mut context_chain = Vec::new();
1203 for view_id in &responder_chain {
1204 if let Some(view) = self.cx.views.get(&(window_id, *view_id)) {
1205 context_chain.push(view.keymap_context(self.as_ref()));
1206 } else {
1207 return Err(anyhow!(
1208 "View {} in responder chain does not exist",
1209 view_id
1210 ));
1211 }
1212 }
1213
1214 let mut pending = false;
1215 for (i, cx) in context_chain.iter().enumerate().rev() {
1216 match self
1217 .keystroke_matcher
1218 .push_keystroke(keystroke.clone(), responder_chain[i], cx)
1219 {
1220 MatchResult::None => {}
1221 MatchResult::Pending => pending = true,
1222 MatchResult::Action(action) => {
1223 if self.dispatch_action_any(window_id, &responder_chain[0..=i], action.as_ref())
1224 {
1225 self.keystroke_matcher.clear_pending();
1226 return Ok(true);
1227 }
1228 }
1229 }
1230 }
1231
1232 Ok(pending)
1233 }
1234
1235 pub fn add_model<T, F>(&mut self, build_model: F) -> ModelHandle<T>
1236 where
1237 T: Entity,
1238 F: FnOnce(&mut ModelContext<T>) -> T,
1239 {
1240 self.update(|this| {
1241 let model_id = post_inc(&mut this.next_entity_id);
1242 let handle = ModelHandle::new(model_id, &this.cx.ref_counts);
1243 let mut cx = ModelContext::new(this, model_id);
1244 let model = build_model(&mut cx);
1245 this.cx.models.insert(model_id, Box::new(model));
1246 handle
1247 })
1248 }
1249
1250 pub fn add_window<T, F>(
1251 &mut self,
1252 window_options: WindowOptions,
1253 build_root_view: F,
1254 ) -> (usize, ViewHandle<T>)
1255 where
1256 T: View,
1257 F: FnOnce(&mut ViewContext<T>) -> T,
1258 {
1259 self.update(|this| {
1260 let window_id = post_inc(&mut this.next_window_id);
1261 let root_view = this.add_view(window_id, build_root_view);
1262
1263 this.cx.windows.insert(
1264 window_id,
1265 Window {
1266 root_view: root_view.clone().into(),
1267 focused_view_id: root_view.id(),
1268 invalidation: None,
1269 },
1270 );
1271 this.open_platform_window(window_id, window_options);
1272 root_view.update(this, |view, cx| {
1273 view.on_focus(cx);
1274 cx.notify();
1275 });
1276
1277 (window_id, root_view)
1278 })
1279 }
1280
1281 pub fn remove_window(&mut self, window_id: usize) {
1282 self.cx.windows.remove(&window_id);
1283 self.presenters_and_platform_windows.remove(&window_id);
1284 self.remove_dropped_entities();
1285 self.flush_effects();
1286 }
1287
1288 fn open_platform_window(&mut self, window_id: usize, window_options: WindowOptions) {
1289 let mut window =
1290 self.cx
1291 .platform
1292 .open_window(window_id, window_options, self.foreground.clone());
1293 let presenter = Rc::new(RefCell::new(
1294 self.build_presenter(window_id, window.titlebar_height()),
1295 ));
1296
1297 {
1298 let mut app = self.upgrade();
1299 let presenter = presenter.clone();
1300 window.on_event(Box::new(move |event| {
1301 app.update(|cx| {
1302 if let Event::KeyDown { keystroke, .. } = &event {
1303 if cx
1304 .dispatch_keystroke(
1305 window_id,
1306 presenter.borrow().dispatch_path(cx.as_ref()),
1307 keystroke,
1308 )
1309 .unwrap()
1310 {
1311 return;
1312 }
1313 }
1314
1315 presenter.borrow_mut().dispatch_event(event, cx);
1316 })
1317 }));
1318 }
1319
1320 {
1321 let mut app = self.upgrade();
1322 window.on_resize(Box::new(move || {
1323 app.update(|cx| cx.resize_window(window_id))
1324 }));
1325 }
1326
1327 {
1328 let mut app = self.upgrade();
1329 window.on_close(Box::new(move || {
1330 app.update(|cx| cx.remove_window(window_id));
1331 }));
1332 }
1333
1334 self.presenters_and_platform_windows
1335 .insert(window_id, (presenter.clone(), window));
1336
1337 self.on_debug_elements(window_id, move |cx| {
1338 presenter.borrow().debug_elements(cx).unwrap()
1339 });
1340 }
1341
1342 pub fn build_presenter(&mut self, window_id: usize, titlebar_height: f32) -> Presenter {
1343 Presenter::new(
1344 window_id,
1345 titlebar_height,
1346 self.cx.font_cache.clone(),
1347 TextLayoutCache::new(self.cx.platform.fonts()),
1348 self.assets.clone(),
1349 self,
1350 )
1351 }
1352
1353 pub fn build_render_context<V: View>(
1354 &mut self,
1355 window_id: usize,
1356 view_id: usize,
1357 titlebar_height: f32,
1358 refreshing: bool,
1359 ) -> RenderContext<V> {
1360 RenderContext {
1361 app: self,
1362 titlebar_height,
1363 refreshing,
1364 window_id,
1365 view_id,
1366 view_type: PhantomData,
1367 }
1368 }
1369
1370 pub fn add_view<T, F>(&mut self, window_id: usize, build_view: F) -> ViewHandle<T>
1371 where
1372 T: View,
1373 F: FnOnce(&mut ViewContext<T>) -> T,
1374 {
1375 self.add_option_view(window_id, |cx| Some(build_view(cx)))
1376 .unwrap()
1377 }
1378
1379 pub fn add_option_view<T, F>(
1380 &mut self,
1381 window_id: usize,
1382 build_view: F,
1383 ) -> Option<ViewHandle<T>>
1384 where
1385 T: View,
1386 F: FnOnce(&mut ViewContext<T>) -> Option<T>,
1387 {
1388 self.update(|this| {
1389 let view_id = post_inc(&mut this.next_entity_id);
1390 let mut cx = ViewContext::new(this, window_id, view_id);
1391 let handle = if let Some(view) = build_view(&mut cx) {
1392 this.cx.views.insert((window_id, view_id), Box::new(view));
1393 if let Some(window) = this.cx.windows.get_mut(&window_id) {
1394 window
1395 .invalidation
1396 .get_or_insert_with(Default::default)
1397 .updated
1398 .insert(view_id);
1399 }
1400 Some(ViewHandle::new(window_id, view_id, &this.cx.ref_counts))
1401 } else {
1402 None
1403 };
1404 handle
1405 })
1406 }
1407
1408 pub fn element_state<Tag: 'static, T: 'static + Default>(
1409 &mut self,
1410 id: ElementStateId,
1411 ) -> ElementStateHandle<T> {
1412 let key = (TypeId::of::<Tag>(), id);
1413 self.cx
1414 .element_states
1415 .entry(key)
1416 .or_insert_with(|| Box::new(T::default()));
1417 ElementStateHandle::new(
1418 TypeId::of::<Tag>(),
1419 id,
1420 self.frame_count,
1421 &self.cx.ref_counts,
1422 )
1423 }
1424
1425 fn remove_dropped_entities(&mut self) {
1426 loop {
1427 let (dropped_models, dropped_views, dropped_element_states) =
1428 self.cx.ref_counts.lock().take_dropped();
1429 if dropped_models.is_empty()
1430 && dropped_views.is_empty()
1431 && dropped_element_states.is_empty()
1432 {
1433 break;
1434 }
1435
1436 for model_id in dropped_models {
1437 self.subscriptions.lock().remove(&model_id);
1438 self.observations.lock().remove(&model_id);
1439 let mut model = self.cx.models.remove(&model_id).unwrap();
1440 model.release(self);
1441 self.pending_effects.push_back(Effect::Release {
1442 entity_id: model_id,
1443 });
1444 }
1445
1446 for (window_id, view_id) in dropped_views {
1447 self.subscriptions.lock().remove(&view_id);
1448 self.observations.lock().remove(&view_id);
1449 let mut view = self.cx.views.remove(&(window_id, view_id)).unwrap();
1450 view.release(self);
1451 let change_focus_to = self.cx.windows.get_mut(&window_id).and_then(|window| {
1452 window
1453 .invalidation
1454 .get_or_insert_with(Default::default)
1455 .removed
1456 .push(view_id);
1457 if window.focused_view_id == view_id {
1458 Some(window.root_view.id())
1459 } else {
1460 None
1461 }
1462 });
1463
1464 if let Some(view_id) = change_focus_to {
1465 self.focus(window_id, view_id);
1466 }
1467
1468 self.pending_effects
1469 .push_back(Effect::Release { entity_id: view_id });
1470 }
1471
1472 for key in dropped_element_states {
1473 self.cx.element_states.remove(&key);
1474 }
1475 }
1476 }
1477
1478 fn flush_effects(&mut self) {
1479 self.pending_flushes = self.pending_flushes.saturating_sub(1);
1480
1481 if !self.flushing_effects && self.pending_flushes == 0 {
1482 self.flushing_effects = true;
1483
1484 let mut refreshing = false;
1485 loop {
1486 if let Some(effect) = self.pending_effects.pop_front() {
1487 match effect {
1488 Effect::Event { entity_id, payload } => self.emit_event(entity_id, payload),
1489 Effect::ModelNotification { model_id } => {
1490 self.notify_model_observers(model_id)
1491 }
1492 Effect::ViewNotification { window_id, view_id } => {
1493 self.notify_view_observers(window_id, view_id)
1494 }
1495 Effect::Deferred(callback) => callback(self),
1496 Effect::Release { entity_id } => self.notify_release_observers(entity_id),
1497 Effect::Focus { window_id, view_id } => {
1498 self.focus(window_id, view_id);
1499 }
1500 Effect::ResizeWindow { window_id } => {
1501 if let Some(window) = self.cx.windows.get_mut(&window_id) {
1502 window
1503 .invalidation
1504 .get_or_insert(WindowInvalidation::default());
1505 }
1506 }
1507 Effect::RefreshWindows => {
1508 refreshing = true;
1509 }
1510 }
1511 self.pending_notifications.clear();
1512 self.remove_dropped_entities();
1513 } else {
1514 self.remove_dropped_entities();
1515 if refreshing {
1516 self.perform_window_refresh();
1517 } else {
1518 self.update_windows();
1519 }
1520
1521 if self.pending_effects.is_empty() {
1522 self.flushing_effects = false;
1523 self.pending_notifications.clear();
1524 break;
1525 } else {
1526 refreshing = false;
1527 }
1528 }
1529 }
1530 }
1531 }
1532
1533 fn update_windows(&mut self) {
1534 let mut invalidations = HashMap::new();
1535 for (window_id, window) in &mut self.cx.windows {
1536 if let Some(invalidation) = window.invalidation.take() {
1537 invalidations.insert(*window_id, invalidation);
1538 }
1539 }
1540
1541 for (window_id, invalidation) in invalidations {
1542 if let Some((presenter, mut window)) =
1543 self.presenters_and_platform_windows.remove(&window_id)
1544 {
1545 {
1546 let mut presenter = presenter.borrow_mut();
1547 presenter.invalidate(invalidation, self);
1548 let scene =
1549 presenter.build_scene(window.size(), window.scale_factor(), false, self);
1550 window.present_scene(scene);
1551 }
1552 self.presenters_and_platform_windows
1553 .insert(window_id, (presenter, window));
1554 }
1555 }
1556 }
1557
1558 fn resize_window(&mut self, window_id: usize) {
1559 self.pending_effects
1560 .push_back(Effect::ResizeWindow { window_id });
1561 }
1562
1563 pub fn refresh_windows(&mut self) {
1564 self.pending_effects.push_back(Effect::RefreshWindows);
1565 }
1566
1567 fn perform_window_refresh(&mut self) {
1568 let mut presenters = mem::take(&mut self.presenters_and_platform_windows);
1569 for (window_id, (presenter, window)) in &mut presenters {
1570 let invalidation = self
1571 .cx
1572 .windows
1573 .get_mut(&window_id)
1574 .unwrap()
1575 .invalidation
1576 .take();
1577 let mut presenter = presenter.borrow_mut();
1578 presenter.refresh(invalidation, self);
1579 let scene = presenter.build_scene(window.size(), window.scale_factor(), true, self);
1580 window.present_scene(scene);
1581 }
1582 self.presenters_and_platform_windows = presenters;
1583 }
1584
1585 pub fn set_cursor_style(&mut self, style: CursorStyle) -> CursorStyleHandle {
1586 self.platform.set_cursor_style(style);
1587 let id = self.next_cursor_style_handle_id.fetch_add(1, SeqCst);
1588 CursorStyleHandle {
1589 id,
1590 next_cursor_style_handle_id: self.next_cursor_style_handle_id.clone(),
1591 platform: self.platform(),
1592 }
1593 }
1594
1595 fn emit_event(&mut self, entity_id: usize, payload: Box<dyn Any>) {
1596 let callbacks = self.subscriptions.lock().remove(&entity_id);
1597 if let Some(callbacks) = callbacks {
1598 for (id, mut callback) in callbacks {
1599 let alive = callback(payload.as_ref(), self);
1600 if alive {
1601 self.subscriptions
1602 .lock()
1603 .entry(entity_id)
1604 .or_default()
1605 .insert(id, callback);
1606 }
1607 }
1608 }
1609 }
1610
1611 fn notify_model_observers(&mut self, observed_id: usize) {
1612 let callbacks = self.observations.lock().remove(&observed_id);
1613 if let Some(callbacks) = callbacks {
1614 if self.cx.models.contains_key(&observed_id) {
1615 for (id, mut callback) in callbacks {
1616 let alive = callback(self);
1617 if alive {
1618 self.observations
1619 .lock()
1620 .entry(observed_id)
1621 .or_default()
1622 .insert(id, callback);
1623 }
1624 }
1625 }
1626 }
1627 }
1628
1629 fn notify_view_observers(&mut self, observed_window_id: usize, observed_view_id: usize) {
1630 if let Some(window) = self.cx.windows.get_mut(&observed_window_id) {
1631 window
1632 .invalidation
1633 .get_or_insert_with(Default::default)
1634 .updated
1635 .insert(observed_view_id);
1636 }
1637
1638 let callbacks = self.observations.lock().remove(&observed_view_id);
1639 if let Some(callbacks) = callbacks {
1640 if self
1641 .cx
1642 .views
1643 .contains_key(&(observed_window_id, observed_view_id))
1644 {
1645 for (id, mut callback) in callbacks {
1646 let alive = callback(self);
1647 if alive {
1648 self.observations
1649 .lock()
1650 .entry(observed_view_id)
1651 .or_default()
1652 .insert(id, callback);
1653 }
1654 }
1655 }
1656 }
1657 }
1658
1659 fn notify_release_observers(&mut self, entity_id: usize) {
1660 let callbacks = self.release_observations.lock().remove(&entity_id);
1661 if let Some(callbacks) = callbacks {
1662 for (_, mut callback) in callbacks {
1663 callback(self);
1664 }
1665 }
1666 }
1667
1668 fn focus(&mut self, window_id: usize, focused_id: usize) {
1669 if self
1670 .cx
1671 .windows
1672 .get(&window_id)
1673 .map(|w| w.focused_view_id)
1674 .map_or(false, |cur_focused| cur_focused == focused_id)
1675 {
1676 return;
1677 }
1678
1679 self.update(|this| {
1680 let blurred_id = this.cx.windows.get_mut(&window_id).map(|window| {
1681 let blurred_id = window.focused_view_id;
1682 window.focused_view_id = focused_id;
1683 blurred_id
1684 });
1685
1686 if let Some(blurred_id) = blurred_id {
1687 if let Some(mut blurred_view) = this.cx.views.remove(&(window_id, blurred_id)) {
1688 blurred_view.on_blur(this, window_id, blurred_id);
1689 this.cx.views.insert((window_id, blurred_id), blurred_view);
1690 }
1691 }
1692
1693 if let Some(mut focused_view) = this.cx.views.remove(&(window_id, focused_id)) {
1694 focused_view.on_focus(this, window_id, focused_id);
1695 this.cx.views.insert((window_id, focused_id), focused_view);
1696 }
1697 })
1698 }
1699
1700 pub fn spawn<F, Fut, T>(&self, f: F) -> Task<T>
1701 where
1702 F: FnOnce(AsyncAppContext) -> Fut,
1703 Fut: 'static + Future<Output = T>,
1704 T: 'static,
1705 {
1706 let future = f(self.to_async());
1707 let cx = self.to_async();
1708 self.foreground.spawn(async move {
1709 let result = future.await;
1710 cx.0.borrow_mut().flush_effects();
1711 result
1712 })
1713 }
1714
1715 pub fn to_async(&self) -> AsyncAppContext {
1716 AsyncAppContext(self.weak_self.as_ref().unwrap().upgrade().unwrap())
1717 }
1718
1719 pub fn write_to_clipboard(&self, item: ClipboardItem) {
1720 self.cx.platform.write_to_clipboard(item);
1721 }
1722
1723 pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
1724 self.cx.platform.read_from_clipboard()
1725 }
1726}
1727
1728impl ReadModel for MutableAppContext {
1729 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
1730 if let Some(model) = self.cx.models.get(&handle.model_id) {
1731 model
1732 .as_any()
1733 .downcast_ref()
1734 .expect("downcast is type safe")
1735 } else {
1736 panic!("circular model reference");
1737 }
1738 }
1739}
1740
1741impl UpdateModel for MutableAppContext {
1742 fn update_model<T: Entity, V>(
1743 &mut self,
1744 handle: &ModelHandle<T>,
1745 update: &mut dyn FnMut(&mut T, &mut ModelContext<T>) -> V,
1746 ) -> V {
1747 if let Some(mut model) = self.cx.models.remove(&handle.model_id) {
1748 self.update(|this| {
1749 let mut cx = ModelContext::new(this, handle.model_id);
1750 let result = update(
1751 model
1752 .as_any_mut()
1753 .downcast_mut()
1754 .expect("downcast is type safe"),
1755 &mut cx,
1756 );
1757 this.cx.models.insert(handle.model_id, model);
1758 result
1759 })
1760 } else {
1761 panic!("circular model update");
1762 }
1763 }
1764}
1765
1766impl UpgradeModelHandle for MutableAppContext {
1767 fn upgrade_model_handle<T: Entity>(
1768 &self,
1769 handle: &WeakModelHandle<T>,
1770 ) -> Option<ModelHandle<T>> {
1771 self.cx.upgrade_model_handle(handle)
1772 }
1773
1774 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
1775 self.cx.upgrade_any_model_handle(handle)
1776 }
1777}
1778
1779impl UpgradeViewHandle for MutableAppContext {
1780 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
1781 self.cx.upgrade_view_handle(handle)
1782 }
1783}
1784
1785impl ReadView for MutableAppContext {
1786 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
1787 if let Some(view) = self.cx.views.get(&(handle.window_id, handle.view_id)) {
1788 view.as_any().downcast_ref().expect("downcast is type safe")
1789 } else {
1790 panic!("circular view reference");
1791 }
1792 }
1793}
1794
1795impl UpdateView for MutableAppContext {
1796 fn update_view<T, S>(
1797 &mut self,
1798 handle: &ViewHandle<T>,
1799 update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
1800 ) -> S
1801 where
1802 T: View,
1803 {
1804 self.update(|this| {
1805 let mut view = this
1806 .cx
1807 .views
1808 .remove(&(handle.window_id, handle.view_id))
1809 .expect("circular view update");
1810
1811 let mut cx = ViewContext::new(this, handle.window_id, handle.view_id);
1812 let result = update(
1813 view.as_any_mut()
1814 .downcast_mut()
1815 .expect("downcast is type safe"),
1816 &mut cx,
1817 );
1818 this.cx
1819 .views
1820 .insert((handle.window_id, handle.view_id), view);
1821 result
1822 })
1823 }
1824}
1825
1826impl AsRef<AppContext> for MutableAppContext {
1827 fn as_ref(&self) -> &AppContext {
1828 &self.cx
1829 }
1830}
1831
1832impl Deref for MutableAppContext {
1833 type Target = AppContext;
1834
1835 fn deref(&self) -> &Self::Target {
1836 &self.cx
1837 }
1838}
1839
1840pub struct AppContext {
1841 models: HashMap<usize, Box<dyn AnyModel>>,
1842 views: HashMap<(usize, usize), Box<dyn AnyView>>,
1843 windows: HashMap<usize, Window>,
1844 element_states: HashMap<(TypeId, ElementStateId), Box<dyn Any>>,
1845 background: Arc<executor::Background>,
1846 ref_counts: Arc<Mutex<RefCounts>>,
1847 font_cache: Arc<FontCache>,
1848 platform: Arc<dyn Platform>,
1849}
1850
1851impl AppContext {
1852 pub fn root_view_id(&self, window_id: usize) -> Option<usize> {
1853 self.windows
1854 .get(&window_id)
1855 .map(|window| window.root_view.id())
1856 }
1857
1858 pub fn focused_view_id(&self, window_id: usize) -> Option<usize> {
1859 self.windows
1860 .get(&window_id)
1861 .map(|window| window.focused_view_id)
1862 }
1863
1864 pub fn background(&self) -> &Arc<executor::Background> {
1865 &self.background
1866 }
1867
1868 pub fn font_cache(&self) -> &Arc<FontCache> {
1869 &self.font_cache
1870 }
1871
1872 pub fn platform(&self) -> &Arc<dyn Platform> {
1873 &self.platform
1874 }
1875}
1876
1877impl ReadModel for AppContext {
1878 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
1879 if let Some(model) = self.models.get(&handle.model_id) {
1880 model
1881 .as_any()
1882 .downcast_ref()
1883 .expect("downcast should be type safe")
1884 } else {
1885 panic!("circular model reference");
1886 }
1887 }
1888}
1889
1890impl UpgradeModelHandle for AppContext {
1891 fn upgrade_model_handle<T: Entity>(
1892 &self,
1893 handle: &WeakModelHandle<T>,
1894 ) -> Option<ModelHandle<T>> {
1895 if self.models.contains_key(&handle.model_id) {
1896 Some(ModelHandle::new(handle.model_id, &self.ref_counts))
1897 } else {
1898 None
1899 }
1900 }
1901
1902 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
1903 if self.models.contains_key(&handle.model_id) {
1904 self.ref_counts.lock().inc_model(handle.model_id);
1905 Some(AnyModelHandle {
1906 model_id: handle.model_id,
1907 model_type: handle.model_type,
1908 ref_counts: self.ref_counts.clone(),
1909 })
1910 } else {
1911 None
1912 }
1913 }
1914}
1915
1916impl UpgradeViewHandle for AppContext {
1917 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
1918 if self.ref_counts.lock().is_entity_alive(handle.view_id) {
1919 Some(ViewHandle::new(
1920 handle.window_id,
1921 handle.view_id,
1922 &self.ref_counts,
1923 ))
1924 } else {
1925 None
1926 }
1927 }
1928}
1929
1930impl ReadView for AppContext {
1931 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
1932 if let Some(view) = self.views.get(&(handle.window_id, handle.view_id)) {
1933 view.as_any()
1934 .downcast_ref()
1935 .expect("downcast should be type safe")
1936 } else {
1937 panic!("circular view reference");
1938 }
1939 }
1940}
1941
1942struct Window {
1943 root_view: AnyViewHandle,
1944 focused_view_id: usize,
1945 invalidation: Option<WindowInvalidation>,
1946}
1947
1948#[derive(Default, Clone)]
1949pub struct WindowInvalidation {
1950 pub updated: HashSet<usize>,
1951 pub removed: Vec<usize>,
1952}
1953
1954pub enum Effect {
1955 Event {
1956 entity_id: usize,
1957 payload: Box<dyn Any>,
1958 },
1959 ModelNotification {
1960 model_id: usize,
1961 },
1962 ViewNotification {
1963 window_id: usize,
1964 view_id: usize,
1965 },
1966 Deferred(Box<dyn FnOnce(&mut MutableAppContext)>),
1967 Release {
1968 entity_id: usize,
1969 },
1970 Focus {
1971 window_id: usize,
1972 view_id: usize,
1973 },
1974 ResizeWindow {
1975 window_id: usize,
1976 },
1977 RefreshWindows,
1978}
1979
1980impl Debug for Effect {
1981 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1982 match self {
1983 Effect::Event { entity_id, .. } => f
1984 .debug_struct("Effect::Event")
1985 .field("entity_id", entity_id)
1986 .finish(),
1987 Effect::ModelNotification { model_id } => f
1988 .debug_struct("Effect::ModelNotification")
1989 .field("model_id", model_id)
1990 .finish(),
1991 Effect::ViewNotification { window_id, view_id } => f
1992 .debug_struct("Effect::ViewNotification")
1993 .field("window_id", window_id)
1994 .field("view_id", view_id)
1995 .finish(),
1996 Effect::Deferred(_) => f.debug_struct("Effect::Deferred").finish(),
1997 Effect::Release { entity_id } => f
1998 .debug_struct("Effect::Release")
1999 .field("entity_id", entity_id)
2000 .finish(),
2001 Effect::Focus { window_id, view_id } => f
2002 .debug_struct("Effect::Focus")
2003 .field("window_id", window_id)
2004 .field("view_id", view_id)
2005 .finish(),
2006 Effect::ResizeWindow { window_id } => f
2007 .debug_struct("Effect::RefreshWindow")
2008 .field("window_id", window_id)
2009 .finish(),
2010 Effect::RefreshWindows => f.debug_struct("Effect::FullViewRefresh").finish(),
2011 }
2012 }
2013}
2014
2015pub trait AnyModel {
2016 fn as_any(&self) -> &dyn Any;
2017 fn as_any_mut(&mut self) -> &mut dyn Any;
2018 fn release(&mut self, cx: &mut MutableAppContext);
2019 fn app_will_quit(
2020 &mut self,
2021 cx: &mut MutableAppContext,
2022 ) -> Option<Pin<Box<dyn 'static + Future<Output = ()>>>>;
2023}
2024
2025impl<T> AnyModel for T
2026where
2027 T: Entity,
2028{
2029 fn as_any(&self) -> &dyn Any {
2030 self
2031 }
2032
2033 fn as_any_mut(&mut self) -> &mut dyn Any {
2034 self
2035 }
2036
2037 fn release(&mut self, cx: &mut MutableAppContext) {
2038 self.release(cx);
2039 }
2040
2041 fn app_will_quit(
2042 &mut self,
2043 cx: &mut MutableAppContext,
2044 ) -> Option<Pin<Box<dyn 'static + Future<Output = ()>>>> {
2045 self.app_will_quit(cx)
2046 }
2047}
2048
2049pub trait AnyView {
2050 fn as_any(&self) -> &dyn Any;
2051 fn as_any_mut(&mut self) -> &mut dyn Any;
2052 fn release(&mut self, cx: &mut MutableAppContext);
2053 fn app_will_quit(
2054 &mut self,
2055 cx: &mut MutableAppContext,
2056 ) -> Option<Pin<Box<dyn 'static + Future<Output = ()>>>>;
2057 fn ui_name(&self) -> &'static str;
2058 fn render<'a>(
2059 &mut self,
2060 window_id: usize,
2061 view_id: usize,
2062 titlebar_height: f32,
2063 refreshing: bool,
2064 cx: &mut MutableAppContext,
2065 ) -> ElementBox;
2066 fn on_focus(&mut self, cx: &mut MutableAppContext, window_id: usize, view_id: usize);
2067 fn on_blur(&mut self, cx: &mut MutableAppContext, window_id: usize, view_id: usize);
2068 fn keymap_context(&self, cx: &AppContext) -> keymap::Context;
2069}
2070
2071impl<T> AnyView for T
2072where
2073 T: View,
2074{
2075 fn as_any(&self) -> &dyn Any {
2076 self
2077 }
2078
2079 fn as_any_mut(&mut self) -> &mut dyn Any {
2080 self
2081 }
2082
2083 fn release(&mut self, cx: &mut MutableAppContext) {
2084 self.release(cx);
2085 }
2086
2087 fn app_will_quit(
2088 &mut self,
2089 cx: &mut MutableAppContext,
2090 ) -> Option<Pin<Box<dyn 'static + Future<Output = ()>>>> {
2091 self.app_will_quit(cx)
2092 }
2093
2094 fn ui_name(&self) -> &'static str {
2095 T::ui_name()
2096 }
2097
2098 fn render<'a>(
2099 &mut self,
2100 window_id: usize,
2101 view_id: usize,
2102 titlebar_height: f32,
2103 refreshing: bool,
2104 cx: &mut MutableAppContext,
2105 ) -> ElementBox {
2106 View::render(
2107 self,
2108 &mut RenderContext {
2109 window_id,
2110 view_id,
2111 app: cx,
2112 view_type: PhantomData::<T>,
2113 titlebar_height,
2114 refreshing,
2115 },
2116 )
2117 }
2118
2119 fn on_focus(&mut self, cx: &mut MutableAppContext, window_id: usize, view_id: usize) {
2120 let mut cx = ViewContext::new(cx, window_id, view_id);
2121 View::on_focus(self, &mut cx);
2122 }
2123
2124 fn on_blur(&mut self, cx: &mut MutableAppContext, window_id: usize, view_id: usize) {
2125 let mut cx = ViewContext::new(cx, window_id, view_id);
2126 View::on_blur(self, &mut cx);
2127 }
2128
2129 fn keymap_context(&self, cx: &AppContext) -> keymap::Context {
2130 View::keymap_context(self, cx)
2131 }
2132}
2133
2134pub struct ModelContext<'a, T: ?Sized> {
2135 app: &'a mut MutableAppContext,
2136 model_id: usize,
2137 model_type: PhantomData<T>,
2138 halt_stream: bool,
2139}
2140
2141impl<'a, T: Entity> ModelContext<'a, T> {
2142 fn new(app: &'a mut MutableAppContext, model_id: usize) -> Self {
2143 Self {
2144 app,
2145 model_id,
2146 model_type: PhantomData,
2147 halt_stream: false,
2148 }
2149 }
2150
2151 pub fn background(&self) -> &Arc<executor::Background> {
2152 &self.app.cx.background
2153 }
2154
2155 pub fn halt_stream(&mut self) {
2156 self.halt_stream = true;
2157 }
2158
2159 pub fn model_id(&self) -> usize {
2160 self.model_id
2161 }
2162
2163 pub fn add_model<S, F>(&mut self, build_model: F) -> ModelHandle<S>
2164 where
2165 S: Entity,
2166 F: FnOnce(&mut ModelContext<S>) -> S,
2167 {
2168 self.app.add_model(build_model)
2169 }
2170
2171 pub fn emit(&mut self, payload: T::Event) {
2172 self.app.pending_effects.push_back(Effect::Event {
2173 entity_id: self.model_id,
2174 payload: Box::new(payload),
2175 });
2176 }
2177
2178 pub fn notify(&mut self) {
2179 self.app.notify_model(self.model_id);
2180 }
2181
2182 pub fn subscribe<S: Entity, F>(
2183 &mut self,
2184 handle: &ModelHandle<S>,
2185 mut callback: F,
2186 ) -> Subscription
2187 where
2188 S::Event: 'static,
2189 F: 'static + FnMut(&mut T, ModelHandle<S>, &S::Event, &mut ModelContext<T>),
2190 {
2191 let subscriber = self.weak_handle();
2192 self.app
2193 .subscribe_internal(handle, move |emitter, event, cx| {
2194 if let Some(subscriber) = subscriber.upgrade(cx) {
2195 subscriber.update(cx, |subscriber, cx| {
2196 callback(subscriber, emitter, event, cx);
2197 });
2198 true
2199 } else {
2200 false
2201 }
2202 })
2203 }
2204
2205 pub fn observe<S, F>(&mut self, handle: &ModelHandle<S>, mut callback: F) -> Subscription
2206 where
2207 S: Entity,
2208 F: 'static + FnMut(&mut T, ModelHandle<S>, &mut ModelContext<T>),
2209 {
2210 let observer = self.weak_handle();
2211 self.app.observe_internal(handle, move |observed, cx| {
2212 if let Some(observer) = observer.upgrade(cx) {
2213 observer.update(cx, |observer, cx| {
2214 callback(observer, observed, cx);
2215 });
2216 true
2217 } else {
2218 false
2219 }
2220 })
2221 }
2222
2223 pub fn observe_release<S, F>(
2224 &mut self,
2225 handle: &ModelHandle<S>,
2226 mut callback: F,
2227 ) -> Subscription
2228 where
2229 S: Entity,
2230 F: 'static + FnMut(&mut T, &mut ModelContext<T>),
2231 {
2232 let observer = self.weak_handle();
2233 self.app.observe_release(handle, move |cx| {
2234 if let Some(observer) = observer.upgrade(cx) {
2235 observer.update(cx, |observer, cx| {
2236 callback(observer, cx);
2237 });
2238 }
2239 })
2240 }
2241
2242 pub fn handle(&self) -> ModelHandle<T> {
2243 ModelHandle::new(self.model_id, &self.app.cx.ref_counts)
2244 }
2245
2246 pub fn weak_handle(&self) -> WeakModelHandle<T> {
2247 WeakModelHandle::new(self.model_id)
2248 }
2249
2250 pub fn spawn<F, Fut, S>(&self, f: F) -> Task<S>
2251 where
2252 F: FnOnce(ModelHandle<T>, AsyncAppContext) -> Fut,
2253 Fut: 'static + Future<Output = S>,
2254 S: 'static,
2255 {
2256 let handle = self.handle();
2257 self.app.spawn(|cx| f(handle, cx))
2258 }
2259
2260 pub fn spawn_weak<F, Fut, S>(&self, f: F) -> Task<S>
2261 where
2262 F: FnOnce(WeakModelHandle<T>, AsyncAppContext) -> Fut,
2263 Fut: 'static + Future<Output = S>,
2264 S: 'static,
2265 {
2266 let handle = self.weak_handle();
2267 self.app.spawn(|cx| f(handle, cx))
2268 }
2269}
2270
2271impl<M> AsRef<AppContext> for ModelContext<'_, M> {
2272 fn as_ref(&self) -> &AppContext {
2273 &self.app.cx
2274 }
2275}
2276
2277impl<M> AsMut<MutableAppContext> for ModelContext<'_, M> {
2278 fn as_mut(&mut self) -> &mut MutableAppContext {
2279 self.app
2280 }
2281}
2282
2283impl<M> ReadModel for ModelContext<'_, M> {
2284 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
2285 self.app.read_model(handle)
2286 }
2287}
2288
2289impl<M> UpdateModel for ModelContext<'_, M> {
2290 fn update_model<T: Entity, V>(
2291 &mut self,
2292 handle: &ModelHandle<T>,
2293 update: &mut dyn FnMut(&mut T, &mut ModelContext<T>) -> V,
2294 ) -> V {
2295 self.app.update_model(handle, update)
2296 }
2297}
2298
2299impl<M> UpgradeModelHandle for ModelContext<'_, M> {
2300 fn upgrade_model_handle<T: Entity>(
2301 &self,
2302 handle: &WeakModelHandle<T>,
2303 ) -> Option<ModelHandle<T>> {
2304 self.cx.upgrade_model_handle(handle)
2305 }
2306
2307 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
2308 self.cx.upgrade_any_model_handle(handle)
2309 }
2310}
2311
2312impl<M> Deref for ModelContext<'_, M> {
2313 type Target = MutableAppContext;
2314
2315 fn deref(&self) -> &Self::Target {
2316 &self.app
2317 }
2318}
2319
2320impl<M> DerefMut for ModelContext<'_, M> {
2321 fn deref_mut(&mut self) -> &mut Self::Target {
2322 &mut self.app
2323 }
2324}
2325
2326pub struct ViewContext<'a, T: ?Sized> {
2327 app: &'a mut MutableAppContext,
2328 window_id: usize,
2329 view_id: usize,
2330 view_type: PhantomData<T>,
2331 halt_action_dispatch: bool,
2332}
2333
2334impl<'a, T: View> ViewContext<'a, T> {
2335 fn new(app: &'a mut MutableAppContext, window_id: usize, view_id: usize) -> Self {
2336 Self {
2337 app,
2338 window_id,
2339 view_id,
2340 view_type: PhantomData,
2341 halt_action_dispatch: true,
2342 }
2343 }
2344
2345 pub fn handle(&self) -> ViewHandle<T> {
2346 ViewHandle::new(self.window_id, self.view_id, &self.app.cx.ref_counts)
2347 }
2348
2349 pub fn weak_handle(&self) -> WeakViewHandle<T> {
2350 WeakViewHandle::new(self.window_id, self.view_id)
2351 }
2352
2353 pub fn window_id(&self) -> usize {
2354 self.window_id
2355 }
2356
2357 pub fn view_id(&self) -> usize {
2358 self.view_id
2359 }
2360
2361 pub fn foreground(&self) -> &Rc<executor::Foreground> {
2362 self.app.foreground()
2363 }
2364
2365 pub fn background_executor(&self) -> &Arc<executor::Background> {
2366 &self.app.cx.background
2367 }
2368
2369 pub fn platform(&self) -> Arc<dyn Platform> {
2370 self.app.platform()
2371 }
2372
2373 pub fn prompt(
2374 &self,
2375 level: PromptLevel,
2376 msg: &str,
2377 answers: &[&str],
2378 ) -> oneshot::Receiver<usize> {
2379 self.app.prompt(self.window_id, level, msg, answers)
2380 }
2381
2382 pub fn prompt_for_paths(
2383 &self,
2384 options: PathPromptOptions,
2385 ) -> oneshot::Receiver<Option<Vec<PathBuf>>> {
2386 self.app.prompt_for_paths(options)
2387 }
2388
2389 pub fn prompt_for_new_path(&self, directory: &Path) -> oneshot::Receiver<Option<PathBuf>> {
2390 self.app.prompt_for_new_path(directory)
2391 }
2392
2393 pub fn debug_elements(&self) -> crate::json::Value {
2394 self.app.debug_elements(self.window_id).unwrap()
2395 }
2396
2397 pub fn focus<S>(&mut self, handle: S)
2398 where
2399 S: Into<AnyViewHandle>,
2400 {
2401 let handle = handle.into();
2402 self.app.pending_effects.push_back(Effect::Focus {
2403 window_id: handle.window_id,
2404 view_id: handle.view_id,
2405 });
2406 }
2407
2408 pub fn focus_self(&mut self) {
2409 self.app.pending_effects.push_back(Effect::Focus {
2410 window_id: self.window_id,
2411 view_id: self.view_id,
2412 });
2413 }
2414
2415 pub fn add_model<S, F>(&mut self, build_model: F) -> ModelHandle<S>
2416 where
2417 S: Entity,
2418 F: FnOnce(&mut ModelContext<S>) -> S,
2419 {
2420 self.app.add_model(build_model)
2421 }
2422
2423 pub fn add_view<S, F>(&mut self, build_view: F) -> ViewHandle<S>
2424 where
2425 S: View,
2426 F: FnOnce(&mut ViewContext<S>) -> S,
2427 {
2428 self.app.add_view(self.window_id, build_view)
2429 }
2430
2431 pub fn add_option_view<S, F>(&mut self, build_view: F) -> Option<ViewHandle<S>>
2432 where
2433 S: View,
2434 F: FnOnce(&mut ViewContext<S>) -> Option<S>,
2435 {
2436 self.app.add_option_view(self.window_id, build_view)
2437 }
2438
2439 pub fn subscribe<E, H, F>(&mut self, handle: &H, mut callback: F) -> Subscription
2440 where
2441 E: Entity,
2442 E::Event: 'static,
2443 H: Handle<E>,
2444 F: 'static + FnMut(&mut T, H, &E::Event, &mut ViewContext<T>),
2445 {
2446 let subscriber = self.weak_handle();
2447 self.app
2448 .subscribe_internal(handle, move |emitter, event, cx| {
2449 if let Some(subscriber) = subscriber.upgrade(cx) {
2450 subscriber.update(cx, |subscriber, cx| {
2451 callback(subscriber, emitter, event, cx);
2452 });
2453 true
2454 } else {
2455 false
2456 }
2457 })
2458 }
2459
2460 pub fn observe<E, F, H>(&mut self, handle: &H, mut callback: F) -> Subscription
2461 where
2462 E: Entity,
2463 H: Handle<E>,
2464 F: 'static + FnMut(&mut T, H, &mut ViewContext<T>),
2465 {
2466 let observer = self.weak_handle();
2467 self.app.observe_internal(handle, move |observed, cx| {
2468 if let Some(observer) = observer.upgrade(cx) {
2469 observer.update(cx, |observer, cx| {
2470 callback(observer, observed, cx);
2471 });
2472 true
2473 } else {
2474 false
2475 }
2476 })
2477 }
2478
2479 pub fn observe_release<E, F, H>(&mut self, handle: &H, mut callback: F) -> Subscription
2480 where
2481 E: Entity,
2482 H: Handle<E>,
2483 F: 'static + FnMut(&mut T, &mut ViewContext<T>),
2484 {
2485 let observer = self.weak_handle();
2486 self.app.observe_release(handle, move |cx| {
2487 if let Some(observer) = observer.upgrade(cx) {
2488 observer.update(cx, |observer, cx| {
2489 callback(observer, cx);
2490 });
2491 }
2492 })
2493 }
2494
2495 pub fn emit(&mut self, payload: T::Event) {
2496 self.app.pending_effects.push_back(Effect::Event {
2497 entity_id: self.view_id,
2498 payload: Box::new(payload),
2499 });
2500 }
2501
2502 pub fn notify(&mut self) {
2503 self.app.notify_view(self.window_id, self.view_id);
2504 }
2505
2506 pub fn defer(&mut self, callback: impl 'static + FnOnce(&mut T, &mut ViewContext<T>)) {
2507 let handle = self.handle();
2508 self.app.defer(Box::new(move |cx| {
2509 handle.update(cx, |view, cx| {
2510 callback(view, cx);
2511 })
2512 }))
2513 }
2514
2515 pub fn propagate_action(&mut self) {
2516 self.halt_action_dispatch = false;
2517 }
2518
2519 pub fn spawn<F, Fut, S>(&self, f: F) -> Task<S>
2520 where
2521 F: FnOnce(ViewHandle<T>, AsyncAppContext) -> Fut,
2522 Fut: 'static + Future<Output = S>,
2523 S: 'static,
2524 {
2525 let handle = self.handle();
2526 self.app.spawn(|cx| f(handle, cx))
2527 }
2528
2529 pub fn spawn_weak<F, Fut, S>(&self, f: F) -> Task<S>
2530 where
2531 F: FnOnce(WeakViewHandle<T>, AsyncAppContext) -> Fut,
2532 Fut: 'static + Future<Output = S>,
2533 S: 'static,
2534 {
2535 let handle = self.weak_handle();
2536 self.app.spawn(|cx| f(handle, cx))
2537 }
2538}
2539
2540pub struct RenderContext<'a, T: View> {
2541 pub app: &'a mut MutableAppContext,
2542 pub titlebar_height: f32,
2543 pub refreshing: bool,
2544 window_id: usize,
2545 view_id: usize,
2546 view_type: PhantomData<T>,
2547}
2548
2549impl<'a, T: View> RenderContext<'a, T> {
2550 pub fn handle(&self) -> WeakViewHandle<T> {
2551 WeakViewHandle::new(self.window_id, self.view_id)
2552 }
2553
2554 pub fn view_id(&self) -> usize {
2555 self.view_id
2556 }
2557}
2558
2559impl AsRef<AppContext> for &AppContext {
2560 fn as_ref(&self) -> &AppContext {
2561 self
2562 }
2563}
2564
2565impl<V: View> Deref for RenderContext<'_, V> {
2566 type Target = MutableAppContext;
2567
2568 fn deref(&self) -> &Self::Target {
2569 self.app
2570 }
2571}
2572
2573impl<V: View> DerefMut for RenderContext<'_, V> {
2574 fn deref_mut(&mut self) -> &mut Self::Target {
2575 self.app
2576 }
2577}
2578
2579impl<V: View> ReadModel for RenderContext<'_, V> {
2580 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
2581 self.app.read_model(handle)
2582 }
2583}
2584
2585impl<V: View> UpdateModel for RenderContext<'_, V> {
2586 fn update_model<T: Entity, O>(
2587 &mut self,
2588 handle: &ModelHandle<T>,
2589 update: &mut dyn FnMut(&mut T, &mut ModelContext<T>) -> O,
2590 ) -> O {
2591 self.app.update_model(handle, update)
2592 }
2593}
2594
2595impl<V: View> ReadView for RenderContext<'_, V> {
2596 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
2597 self.app.read_view(handle)
2598 }
2599}
2600
2601impl<M> AsRef<AppContext> for ViewContext<'_, M> {
2602 fn as_ref(&self) -> &AppContext {
2603 &self.app.cx
2604 }
2605}
2606
2607impl<M> Deref for ViewContext<'_, M> {
2608 type Target = MutableAppContext;
2609
2610 fn deref(&self) -> &Self::Target {
2611 &self.app
2612 }
2613}
2614
2615impl<M> DerefMut for ViewContext<'_, M> {
2616 fn deref_mut(&mut self) -> &mut Self::Target {
2617 &mut self.app
2618 }
2619}
2620
2621impl<M> AsMut<MutableAppContext> for ViewContext<'_, M> {
2622 fn as_mut(&mut self) -> &mut MutableAppContext {
2623 self.app
2624 }
2625}
2626
2627impl<V> ReadModel for ViewContext<'_, V> {
2628 fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
2629 self.app.read_model(handle)
2630 }
2631}
2632
2633impl<V> UpgradeModelHandle for ViewContext<'_, V> {
2634 fn upgrade_model_handle<T: Entity>(
2635 &self,
2636 handle: &WeakModelHandle<T>,
2637 ) -> Option<ModelHandle<T>> {
2638 self.cx.upgrade_model_handle(handle)
2639 }
2640
2641 fn upgrade_any_model_handle(&self, handle: &AnyWeakModelHandle) -> Option<AnyModelHandle> {
2642 self.cx.upgrade_any_model_handle(handle)
2643 }
2644}
2645
2646impl<V> UpgradeViewHandle for ViewContext<'_, V> {
2647 fn upgrade_view_handle<T: View>(&self, handle: &WeakViewHandle<T>) -> Option<ViewHandle<T>> {
2648 self.cx.upgrade_view_handle(handle)
2649 }
2650}
2651
2652impl<V: View> UpdateModel for ViewContext<'_, V> {
2653 fn update_model<T: Entity, O>(
2654 &mut self,
2655 handle: &ModelHandle<T>,
2656 update: &mut dyn FnMut(&mut T, &mut ModelContext<T>) -> O,
2657 ) -> O {
2658 self.app.update_model(handle, update)
2659 }
2660}
2661
2662impl<V: View> ReadView for ViewContext<'_, V> {
2663 fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
2664 self.app.read_view(handle)
2665 }
2666}
2667
2668impl<V: View> UpdateView for ViewContext<'_, V> {
2669 fn update_view<T, S>(
2670 &mut self,
2671 handle: &ViewHandle<T>,
2672 update: &mut dyn FnMut(&mut T, &mut ViewContext<T>) -> S,
2673 ) -> S
2674 where
2675 T: View,
2676 {
2677 self.app.update_view(handle, update)
2678 }
2679}
2680
2681pub trait Handle<T> {
2682 type Weak: 'static;
2683 fn id(&self) -> usize;
2684 fn location(&self) -> EntityLocation;
2685 fn downgrade(&self) -> Self::Weak;
2686 fn upgrade_from(weak: &Self::Weak, cx: &AppContext) -> Option<Self>
2687 where
2688 Self: Sized;
2689}
2690
2691#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
2692pub enum EntityLocation {
2693 Model(usize),
2694 View(usize, usize),
2695}
2696
2697pub struct ModelHandle<T> {
2698 model_id: usize,
2699 model_type: PhantomData<T>,
2700 ref_counts: Arc<Mutex<RefCounts>>,
2701}
2702
2703impl<T: Entity> ModelHandle<T> {
2704 fn new(model_id: usize, ref_counts: &Arc<Mutex<RefCounts>>) -> Self {
2705 ref_counts.lock().inc_model(model_id);
2706 Self {
2707 model_id,
2708 model_type: PhantomData,
2709 ref_counts: ref_counts.clone(),
2710 }
2711 }
2712
2713 pub fn downgrade(&self) -> WeakModelHandle<T> {
2714 WeakModelHandle::new(self.model_id)
2715 }
2716
2717 pub fn id(&self) -> usize {
2718 self.model_id
2719 }
2720
2721 pub fn read<'a, C: ReadModel>(&self, cx: &'a C) -> &'a T {
2722 cx.read_model(self)
2723 }
2724
2725 pub fn read_with<'a, C, F, S>(&self, cx: &C, read: F) -> S
2726 where
2727 C: ReadModelWith,
2728 F: FnOnce(&T, &AppContext) -> S,
2729 {
2730 let mut read = Some(read);
2731 cx.read_model_with(self, &mut |model, cx| {
2732 let read = read.take().unwrap();
2733 read(model, cx)
2734 })
2735 }
2736
2737 pub fn update<C, F, S>(&self, cx: &mut C, update: F) -> S
2738 where
2739 C: UpdateModel,
2740 F: FnOnce(&mut T, &mut ModelContext<T>) -> S,
2741 {
2742 let mut update = Some(update);
2743 cx.update_model(self, &mut |model, cx| {
2744 let update = update.take().unwrap();
2745 update(model, cx)
2746 })
2747 }
2748
2749 pub fn next_notification(&self, cx: &TestAppContext) -> impl Future<Output = ()> {
2750 let (mut tx, mut rx) = mpsc::channel(1);
2751 let mut cx = cx.cx.borrow_mut();
2752 let subscription = cx.observe(self, move |_, _| {
2753 tx.try_send(()).ok();
2754 });
2755
2756 let duration = if std::env::var("CI").is_ok() {
2757 Duration::from_secs(5)
2758 } else {
2759 Duration::from_secs(1)
2760 };
2761
2762 async move {
2763 let notification = timeout(duration, rx.recv())
2764 .await
2765 .expect("next notification timed out");
2766 drop(subscription);
2767 notification.expect("model dropped while test was waiting for its next notification")
2768 }
2769 }
2770
2771 pub fn next_event(&self, cx: &TestAppContext) -> impl Future<Output = T::Event>
2772 where
2773 T::Event: Clone,
2774 {
2775 let (mut tx, mut rx) = mpsc::channel(1);
2776 let mut cx = cx.cx.borrow_mut();
2777 let subscription = cx.subscribe(self, move |_, event, _| {
2778 tx.blocking_send(event.clone()).ok();
2779 });
2780
2781 let duration = if std::env::var("CI").is_ok() {
2782 Duration::from_secs(5)
2783 } else {
2784 Duration::from_secs(1)
2785 };
2786
2787 async move {
2788 let event = timeout(duration, rx.recv())
2789 .await
2790 .expect("next event timed out");
2791 drop(subscription);
2792 event.expect("model dropped while test was waiting for its next event")
2793 }
2794 }
2795
2796 pub fn condition(
2797 &self,
2798 cx: &TestAppContext,
2799 mut predicate: impl FnMut(&T, &AppContext) -> bool,
2800 ) -> impl Future<Output = ()> {
2801 let (tx, mut rx) = mpsc::channel(1024);
2802
2803 let mut cx = cx.cx.borrow_mut();
2804 let subscriptions = (
2805 cx.observe(self, {
2806 let mut tx = tx.clone();
2807 move |_, _| {
2808 tx.blocking_send(()).ok();
2809 }
2810 }),
2811 cx.subscribe(self, {
2812 let mut tx = tx.clone();
2813 move |_, _, _| {
2814 tx.blocking_send(()).ok();
2815 }
2816 }),
2817 );
2818
2819 let cx = cx.weak_self.as_ref().unwrap().upgrade().unwrap();
2820 let handle = self.downgrade();
2821 let duration = if std::env::var("CI").is_ok() {
2822 Duration::from_secs(5)
2823 } else {
2824 Duration::from_secs(1)
2825 };
2826
2827 async move {
2828 timeout(duration, async move {
2829 loop {
2830 {
2831 let cx = cx.borrow();
2832 let cx = cx.as_ref();
2833 if predicate(
2834 handle
2835 .upgrade(cx)
2836 .expect("model dropped with pending condition")
2837 .read(cx),
2838 cx,
2839 ) {
2840 break;
2841 }
2842 }
2843
2844 cx.borrow().foreground().start_waiting();
2845 rx.recv()
2846 .await
2847 .expect("model dropped with pending condition");
2848 cx.borrow().foreground().finish_waiting();
2849 }
2850 })
2851 .await
2852 .expect("condition timed out");
2853 drop(subscriptions);
2854 }
2855 }
2856}
2857
2858impl<T> Clone for ModelHandle<T> {
2859 fn clone(&self) -> Self {
2860 self.ref_counts.lock().inc_model(self.model_id);
2861 Self {
2862 model_id: self.model_id,
2863 model_type: PhantomData,
2864 ref_counts: self.ref_counts.clone(),
2865 }
2866 }
2867}
2868
2869impl<T> PartialEq for ModelHandle<T> {
2870 fn eq(&self, other: &Self) -> bool {
2871 self.model_id == other.model_id
2872 }
2873}
2874
2875impl<T> Eq for ModelHandle<T> {}
2876
2877impl<T> Hash for ModelHandle<T> {
2878 fn hash<H: Hasher>(&self, state: &mut H) {
2879 self.model_id.hash(state);
2880 }
2881}
2882
2883impl<T> std::borrow::Borrow<usize> for ModelHandle<T> {
2884 fn borrow(&self) -> &usize {
2885 &self.model_id
2886 }
2887}
2888
2889impl<T> Debug for ModelHandle<T> {
2890 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2891 f.debug_tuple(&format!("ModelHandle<{}>", type_name::<T>()))
2892 .field(&self.model_id)
2893 .finish()
2894 }
2895}
2896
2897unsafe impl<T> Send for ModelHandle<T> {}
2898unsafe impl<T> Sync for ModelHandle<T> {}
2899
2900impl<T> Drop for ModelHandle<T> {
2901 fn drop(&mut self) {
2902 self.ref_counts.lock().dec_model(self.model_id);
2903 }
2904}
2905
2906impl<T: Entity> Handle<T> for ModelHandle<T> {
2907 type Weak = WeakModelHandle<T>;
2908
2909 fn id(&self) -> usize {
2910 self.model_id
2911 }
2912
2913 fn location(&self) -> EntityLocation {
2914 EntityLocation::Model(self.model_id)
2915 }
2916
2917 fn downgrade(&self) -> Self::Weak {
2918 self.downgrade()
2919 }
2920
2921 fn upgrade_from(weak: &Self::Weak, cx: &AppContext) -> Option<Self>
2922 where
2923 Self: Sized,
2924 {
2925 weak.upgrade(cx)
2926 }
2927}
2928
2929pub struct WeakModelHandle<T> {
2930 model_id: usize,
2931 model_type: PhantomData<T>,
2932}
2933
2934unsafe impl<T> Send for WeakModelHandle<T> {}
2935unsafe impl<T> Sync for WeakModelHandle<T> {}
2936
2937impl<T: Entity> WeakModelHandle<T> {
2938 fn new(model_id: usize) -> Self {
2939 Self {
2940 model_id,
2941 model_type: PhantomData,
2942 }
2943 }
2944
2945 pub fn id(&self) -> usize {
2946 self.model_id
2947 }
2948
2949 pub fn upgrade(&self, cx: &impl UpgradeModelHandle) -> Option<ModelHandle<T>> {
2950 cx.upgrade_model_handle(self)
2951 }
2952}
2953
2954impl<T> Hash for WeakModelHandle<T> {
2955 fn hash<H: Hasher>(&self, state: &mut H) {
2956 self.model_id.hash(state)
2957 }
2958}
2959
2960impl<T> PartialEq for WeakModelHandle<T> {
2961 fn eq(&self, other: &Self) -> bool {
2962 self.model_id == other.model_id
2963 }
2964}
2965
2966impl<T> Eq for WeakModelHandle<T> {}
2967
2968impl<T> Clone for WeakModelHandle<T> {
2969 fn clone(&self) -> Self {
2970 Self {
2971 model_id: self.model_id,
2972 model_type: PhantomData,
2973 }
2974 }
2975}
2976
2977impl<T> Copy for WeakModelHandle<T> {}
2978
2979pub struct ViewHandle<T> {
2980 window_id: usize,
2981 view_id: usize,
2982 view_type: PhantomData<T>,
2983 ref_counts: Arc<Mutex<RefCounts>>,
2984}
2985
2986impl<T: View> ViewHandle<T> {
2987 fn new(window_id: usize, view_id: usize, ref_counts: &Arc<Mutex<RefCounts>>) -> Self {
2988 ref_counts.lock().inc_view(window_id, view_id);
2989 Self {
2990 window_id,
2991 view_id,
2992 view_type: PhantomData,
2993 ref_counts: ref_counts.clone(),
2994 }
2995 }
2996
2997 pub fn downgrade(&self) -> WeakViewHandle<T> {
2998 WeakViewHandle::new(self.window_id, self.view_id)
2999 }
3000
3001 pub fn window_id(&self) -> usize {
3002 self.window_id
3003 }
3004
3005 pub fn id(&self) -> usize {
3006 self.view_id
3007 }
3008
3009 pub fn read<'a, C: ReadView>(&self, cx: &'a C) -> &'a T {
3010 cx.read_view(self)
3011 }
3012
3013 pub fn read_with<C, F, S>(&self, cx: &C, read: F) -> S
3014 where
3015 C: ReadViewWith,
3016 F: FnOnce(&T, &AppContext) -> S,
3017 {
3018 let mut read = Some(read);
3019 cx.read_view_with(self, &mut |view, cx| {
3020 let read = read.take().unwrap();
3021 read(view, cx)
3022 })
3023 }
3024
3025 pub fn update<C, F, S>(&self, cx: &mut C, update: F) -> S
3026 where
3027 C: UpdateView,
3028 F: FnOnce(&mut T, &mut ViewContext<T>) -> S,
3029 {
3030 let mut update = Some(update);
3031 cx.update_view(self, &mut |view, cx| {
3032 let update = update.take().unwrap();
3033 update(view, cx)
3034 })
3035 }
3036
3037 pub fn defer<C, F>(&self, cx: &mut C, update: F)
3038 where
3039 C: AsMut<MutableAppContext>,
3040 F: 'static + FnOnce(&mut T, &mut ViewContext<T>),
3041 {
3042 let this = self.clone();
3043 cx.as_mut().defer(Box::new(move |cx| {
3044 this.update(cx, |view, cx| update(view, cx));
3045 }));
3046 }
3047
3048 pub fn is_focused(&self, cx: &AppContext) -> bool {
3049 cx.focused_view_id(self.window_id)
3050 .map_or(false, |focused_id| focused_id == self.view_id)
3051 }
3052
3053 pub fn next_notification(&self, cx: &TestAppContext) -> impl Future<Output = ()> {
3054 let (mut tx, mut rx) = mpsc::channel(1);
3055 let mut cx = cx.cx.borrow_mut();
3056 let subscription = cx.observe(self, move |_, _| {
3057 tx.try_send(()).ok();
3058 });
3059
3060 let duration = if std::env::var("CI").is_ok() {
3061 Duration::from_secs(5)
3062 } else {
3063 Duration::from_secs(1)
3064 };
3065
3066 async move {
3067 let notification = timeout(duration, rx.recv())
3068 .await
3069 .expect("next notification timed out");
3070 drop(subscription);
3071 notification.expect("model dropped while test was waiting for its next notification")
3072 }
3073 }
3074
3075 pub fn condition(
3076 &self,
3077 cx: &TestAppContext,
3078 mut predicate: impl FnMut(&T, &AppContext) -> bool,
3079 ) -> impl Future<Output = ()> {
3080 let (tx, mut rx) = mpsc::channel(1024);
3081
3082 let mut cx = cx.cx.borrow_mut();
3083 let subscriptions = self.update(&mut *cx, |_, cx| {
3084 (
3085 cx.observe(self, {
3086 let mut tx = tx.clone();
3087 move |_, _, _| {
3088 tx.blocking_send(()).ok();
3089 }
3090 }),
3091 cx.subscribe(self, {
3092 let mut tx = tx.clone();
3093 move |_, _, _, _| {
3094 tx.blocking_send(()).ok();
3095 }
3096 }),
3097 )
3098 });
3099
3100 let cx = cx.weak_self.as_ref().unwrap().upgrade().unwrap();
3101 let handle = self.downgrade();
3102 let duration = if std::env::var("CI").is_ok() {
3103 Duration::from_secs(2)
3104 } else {
3105 Duration::from_millis(500)
3106 };
3107
3108 async move {
3109 timeout(duration, async move {
3110 loop {
3111 {
3112 let cx = cx.borrow();
3113 let cx = cx.as_ref();
3114 if predicate(
3115 handle
3116 .upgrade(cx)
3117 .expect("view dropped with pending condition")
3118 .read(cx),
3119 cx,
3120 ) {
3121 break;
3122 }
3123 }
3124
3125 cx.borrow().foreground().start_waiting();
3126 rx.recv()
3127 .await
3128 .expect("view dropped with pending condition");
3129 cx.borrow().foreground().finish_waiting();
3130 }
3131 })
3132 .await
3133 .expect("condition timed out");
3134 drop(subscriptions);
3135 }
3136 }
3137}
3138
3139impl<T> Clone for ViewHandle<T> {
3140 fn clone(&self) -> Self {
3141 self.ref_counts
3142 .lock()
3143 .inc_view(self.window_id, self.view_id);
3144 Self {
3145 window_id: self.window_id,
3146 view_id: self.view_id,
3147 view_type: PhantomData,
3148 ref_counts: self.ref_counts.clone(),
3149 }
3150 }
3151}
3152
3153impl<T> PartialEq for ViewHandle<T> {
3154 fn eq(&self, other: &Self) -> bool {
3155 self.window_id == other.window_id && self.view_id == other.view_id
3156 }
3157}
3158
3159impl<T> Eq for ViewHandle<T> {}
3160
3161impl<T> Debug for ViewHandle<T> {
3162 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
3163 f.debug_struct(&format!("ViewHandle<{}>", type_name::<T>()))
3164 .field("window_id", &self.window_id)
3165 .field("view_id", &self.view_id)
3166 .finish()
3167 }
3168}
3169
3170impl<T> Drop for ViewHandle<T> {
3171 fn drop(&mut self) {
3172 self.ref_counts
3173 .lock()
3174 .dec_view(self.window_id, self.view_id);
3175 }
3176}
3177
3178impl<T: View> Handle<T> for ViewHandle<T> {
3179 type Weak = WeakViewHandle<T>;
3180
3181 fn id(&self) -> usize {
3182 self.view_id
3183 }
3184
3185 fn location(&self) -> EntityLocation {
3186 EntityLocation::View(self.window_id, self.view_id)
3187 }
3188
3189 fn downgrade(&self) -> Self::Weak {
3190 self.downgrade()
3191 }
3192
3193 fn upgrade_from(weak: &Self::Weak, cx: &AppContext) -> Option<Self>
3194 where
3195 Self: Sized,
3196 {
3197 weak.upgrade(cx)
3198 }
3199}
3200
3201pub struct AnyViewHandle {
3202 window_id: usize,
3203 view_id: usize,
3204 view_type: TypeId,
3205 ref_counts: Arc<Mutex<RefCounts>>,
3206}
3207
3208impl AnyViewHandle {
3209 pub fn id(&self) -> usize {
3210 self.view_id
3211 }
3212
3213 pub fn is<T: 'static>(&self) -> bool {
3214 TypeId::of::<T>() == self.view_type
3215 }
3216
3217 pub fn is_focused(&self, cx: &AppContext) -> bool {
3218 cx.focused_view_id(self.window_id)
3219 .map_or(false, |focused_id| focused_id == self.view_id)
3220 }
3221
3222 pub fn downcast<T: View>(self) -> Option<ViewHandle<T>> {
3223 if self.is::<T>() {
3224 let result = Some(ViewHandle {
3225 window_id: self.window_id,
3226 view_id: self.view_id,
3227 ref_counts: self.ref_counts.clone(),
3228 view_type: PhantomData,
3229 });
3230 unsafe {
3231 Arc::decrement_strong_count(&self.ref_counts);
3232 }
3233 std::mem::forget(self);
3234 result
3235 } else {
3236 None
3237 }
3238 }
3239}
3240
3241impl Clone for AnyViewHandle {
3242 fn clone(&self) -> Self {
3243 self.ref_counts
3244 .lock()
3245 .inc_view(self.window_id, self.view_id);
3246 Self {
3247 window_id: self.window_id,
3248 view_id: self.view_id,
3249 view_type: self.view_type,
3250 ref_counts: self.ref_counts.clone(),
3251 }
3252 }
3253}
3254
3255impl From<&AnyViewHandle> for AnyViewHandle {
3256 fn from(handle: &AnyViewHandle) -> Self {
3257 handle.clone()
3258 }
3259}
3260
3261impl<T: View> From<&ViewHandle<T>> for AnyViewHandle {
3262 fn from(handle: &ViewHandle<T>) -> Self {
3263 handle
3264 .ref_counts
3265 .lock()
3266 .inc_view(handle.window_id, handle.view_id);
3267 AnyViewHandle {
3268 window_id: handle.window_id,
3269 view_id: handle.view_id,
3270 view_type: TypeId::of::<T>(),
3271 ref_counts: handle.ref_counts.clone(),
3272 }
3273 }
3274}
3275
3276impl<T: View> From<ViewHandle<T>> for AnyViewHandle {
3277 fn from(handle: ViewHandle<T>) -> Self {
3278 let any_handle = AnyViewHandle {
3279 window_id: handle.window_id,
3280 view_id: handle.view_id,
3281 view_type: TypeId::of::<T>(),
3282 ref_counts: handle.ref_counts.clone(),
3283 };
3284 unsafe {
3285 Arc::decrement_strong_count(&handle.ref_counts);
3286 }
3287 std::mem::forget(handle);
3288 any_handle
3289 }
3290}
3291
3292impl Drop for AnyViewHandle {
3293 fn drop(&mut self) {
3294 self.ref_counts
3295 .lock()
3296 .dec_view(self.window_id, self.view_id);
3297 }
3298}
3299
3300pub struct AnyModelHandle {
3301 model_id: usize,
3302 model_type: TypeId,
3303 ref_counts: Arc<Mutex<RefCounts>>,
3304}
3305
3306impl AnyModelHandle {
3307 pub fn downcast<T: Entity>(self) -> Option<ModelHandle<T>> {
3308 if self.is::<T>() {
3309 let result = Some(ModelHandle {
3310 model_id: self.model_id,
3311 model_type: PhantomData,
3312 ref_counts: self.ref_counts.clone(),
3313 });
3314 unsafe {
3315 Arc::decrement_strong_count(&self.ref_counts);
3316 }
3317 std::mem::forget(self);
3318 result
3319 } else {
3320 None
3321 }
3322 }
3323
3324 pub fn downgrade(&self) -> AnyWeakModelHandle {
3325 AnyWeakModelHandle {
3326 model_id: self.model_id,
3327 model_type: self.model_type,
3328 }
3329 }
3330
3331 pub fn is<T: Entity>(&self) -> bool {
3332 self.model_type == TypeId::of::<T>()
3333 }
3334}
3335
3336impl<T: Entity> From<ModelHandle<T>> for AnyModelHandle {
3337 fn from(handle: ModelHandle<T>) -> Self {
3338 handle.ref_counts.lock().inc_model(handle.model_id);
3339 Self {
3340 model_id: handle.model_id,
3341 model_type: TypeId::of::<T>(),
3342 ref_counts: handle.ref_counts.clone(),
3343 }
3344 }
3345}
3346
3347impl Clone for AnyModelHandle {
3348 fn clone(&self) -> Self {
3349 self.ref_counts.lock().inc_model(self.model_id);
3350 Self {
3351 model_id: self.model_id,
3352 model_type: self.model_type,
3353 ref_counts: self.ref_counts.clone(),
3354 }
3355 }
3356}
3357
3358impl Drop for AnyModelHandle {
3359 fn drop(&mut self) {
3360 self.ref_counts.lock().dec_model(self.model_id);
3361 }
3362}
3363
3364pub struct AnyWeakModelHandle {
3365 model_id: usize,
3366 model_type: TypeId,
3367}
3368
3369impl AnyWeakModelHandle {
3370 pub fn upgrade(&self, cx: &impl UpgradeModelHandle) -> Option<AnyModelHandle> {
3371 cx.upgrade_any_model_handle(self)
3372 }
3373}
3374
3375pub struct WeakViewHandle<T> {
3376 window_id: usize,
3377 view_id: usize,
3378 view_type: PhantomData<T>,
3379}
3380
3381impl<T: View> WeakViewHandle<T> {
3382 fn new(window_id: usize, view_id: usize) -> Self {
3383 Self {
3384 window_id,
3385 view_id,
3386 view_type: PhantomData,
3387 }
3388 }
3389
3390 pub fn id(&self) -> usize {
3391 self.view_id
3392 }
3393
3394 pub fn upgrade(&self, cx: &impl UpgradeViewHandle) -> Option<ViewHandle<T>> {
3395 cx.upgrade_view_handle(self)
3396 }
3397}
3398
3399impl<T> Clone for WeakViewHandle<T> {
3400 fn clone(&self) -> Self {
3401 Self {
3402 window_id: self.window_id,
3403 view_id: self.view_id,
3404 view_type: PhantomData,
3405 }
3406 }
3407}
3408
3409impl<T> PartialEq for WeakViewHandle<T> {
3410 fn eq(&self, other: &Self) -> bool {
3411 self.window_id == other.window_id && self.view_id == other.view_id
3412 }
3413}
3414
3415impl<T> Eq for WeakViewHandle<T> {}
3416
3417impl<T> Hash for WeakViewHandle<T> {
3418 fn hash<H: Hasher>(&self, state: &mut H) {
3419 self.window_id.hash(state);
3420 self.view_id.hash(state);
3421 }
3422}
3423
3424#[derive(Clone, Copy, PartialEq, Eq, Hash)]
3425pub struct ElementStateId(usize, usize);
3426
3427impl From<usize> for ElementStateId {
3428 fn from(id: usize) -> Self {
3429 Self(id, 0)
3430 }
3431}
3432
3433impl From<(usize, usize)> for ElementStateId {
3434 fn from(id: (usize, usize)) -> Self {
3435 Self(id.0, id.1)
3436 }
3437}
3438
3439pub struct ElementStateHandle<T> {
3440 value_type: PhantomData<T>,
3441 tag_type_id: TypeId,
3442 id: ElementStateId,
3443 ref_counts: Weak<Mutex<RefCounts>>,
3444}
3445
3446impl<T: 'static> ElementStateHandle<T> {
3447 fn new(
3448 tag_type_id: TypeId,
3449 id: ElementStateId,
3450 frame_id: usize,
3451 ref_counts: &Arc<Mutex<RefCounts>>,
3452 ) -> Self {
3453 ref_counts
3454 .lock()
3455 .inc_element_state(tag_type_id, id, frame_id);
3456 Self {
3457 value_type: PhantomData,
3458 tag_type_id,
3459 id,
3460 ref_counts: Arc::downgrade(ref_counts),
3461 }
3462 }
3463
3464 pub fn read<'a>(&self, cx: &'a AppContext) -> &'a T {
3465 cx.element_states
3466 .get(&(self.tag_type_id, self.id))
3467 .unwrap()
3468 .downcast_ref()
3469 .unwrap()
3470 }
3471
3472 pub fn update<C, R>(&self, cx: &mut C, f: impl FnOnce(&mut T, &mut C) -> R) -> R
3473 where
3474 C: DerefMut<Target = MutableAppContext>,
3475 {
3476 let mut element_state = cx
3477 .deref_mut()
3478 .cx
3479 .element_states
3480 .remove(&(self.tag_type_id, self.id))
3481 .unwrap();
3482 let result = f(element_state.downcast_mut().unwrap(), cx);
3483 cx.deref_mut()
3484 .cx
3485 .element_states
3486 .insert((self.tag_type_id, self.id), element_state);
3487 result
3488 }
3489}
3490
3491impl<T> Drop for ElementStateHandle<T> {
3492 fn drop(&mut self) {
3493 if let Some(ref_counts) = self.ref_counts.upgrade() {
3494 ref_counts
3495 .lock()
3496 .dec_element_state(self.tag_type_id, self.id);
3497 }
3498 }
3499}
3500
3501pub struct CursorStyleHandle {
3502 id: usize,
3503 next_cursor_style_handle_id: Arc<AtomicUsize>,
3504 platform: Arc<dyn Platform>,
3505}
3506
3507impl Drop for CursorStyleHandle {
3508 fn drop(&mut self) {
3509 if self.id + 1 == self.next_cursor_style_handle_id.load(SeqCst) {
3510 self.platform.set_cursor_style(CursorStyle::Arrow);
3511 }
3512 }
3513}
3514
3515#[must_use]
3516pub enum Subscription {
3517 Subscription {
3518 id: usize,
3519 entity_id: usize,
3520 subscriptions: Option<Weak<Mutex<HashMap<usize, BTreeMap<usize, SubscriptionCallback>>>>>,
3521 },
3522 Observation {
3523 id: usize,
3524 entity_id: usize,
3525 observations: Option<Weak<Mutex<HashMap<usize, BTreeMap<usize, ObservationCallback>>>>>,
3526 },
3527 ReleaseObservation {
3528 id: usize,
3529 entity_id: usize,
3530 observations:
3531 Option<Weak<Mutex<HashMap<usize, BTreeMap<usize, ReleaseObservationCallback>>>>>,
3532 },
3533}
3534
3535impl Subscription {
3536 pub fn detach(&mut self) {
3537 match self {
3538 Subscription::Subscription { subscriptions, .. } => {
3539 subscriptions.take();
3540 }
3541 Subscription::Observation { observations, .. } => {
3542 observations.take();
3543 }
3544 Subscription::ReleaseObservation { observations, .. } => {
3545 observations.take();
3546 }
3547 }
3548 }
3549}
3550
3551impl Drop for Subscription {
3552 fn drop(&mut self) {
3553 match self {
3554 Subscription::Observation {
3555 id,
3556 entity_id,
3557 observations,
3558 } => {
3559 if let Some(observations) = observations.as_ref().and_then(Weak::upgrade) {
3560 if let Some(observations) = observations.lock().get_mut(entity_id) {
3561 observations.remove(id);
3562 }
3563 }
3564 }
3565 Subscription::ReleaseObservation {
3566 id,
3567 entity_id,
3568 observations,
3569 } => {
3570 if let Some(observations) = observations.as_ref().and_then(Weak::upgrade) {
3571 if let Some(observations) = observations.lock().get_mut(entity_id) {
3572 observations.remove(id);
3573 }
3574 }
3575 }
3576 Subscription::Subscription {
3577 id,
3578 entity_id,
3579 subscriptions,
3580 } => {
3581 if let Some(subscriptions) = subscriptions.as_ref().and_then(Weak::upgrade) {
3582 if let Some(subscriptions) = subscriptions.lock().get_mut(entity_id) {
3583 subscriptions.remove(id);
3584 }
3585 }
3586 }
3587 }
3588 }
3589}
3590
3591#[derive(Default)]
3592struct RefCounts {
3593 entity_counts: HashMap<usize, usize>,
3594 element_state_counts: HashMap<(TypeId, ElementStateId), ElementStateRefCount>,
3595 dropped_models: HashSet<usize>,
3596 dropped_views: HashSet<(usize, usize)>,
3597 dropped_element_states: HashSet<(TypeId, ElementStateId)>,
3598}
3599
3600struct ElementStateRefCount {
3601 ref_count: usize,
3602 frame_id: usize,
3603}
3604
3605impl RefCounts {
3606 fn inc_model(&mut self, model_id: usize) {
3607 match self.entity_counts.entry(model_id) {
3608 Entry::Occupied(mut entry) => {
3609 *entry.get_mut() += 1;
3610 }
3611 Entry::Vacant(entry) => {
3612 entry.insert(1);
3613 self.dropped_models.remove(&model_id);
3614 }
3615 }
3616 }
3617
3618 fn inc_view(&mut self, window_id: usize, view_id: usize) {
3619 match self.entity_counts.entry(view_id) {
3620 Entry::Occupied(mut entry) => *entry.get_mut() += 1,
3621 Entry::Vacant(entry) => {
3622 entry.insert(1);
3623 self.dropped_views.remove(&(window_id, view_id));
3624 }
3625 }
3626 }
3627
3628 fn inc_element_state(&mut self, tag_type_id: TypeId, id: ElementStateId, frame_id: usize) {
3629 match self.element_state_counts.entry((tag_type_id, id)) {
3630 Entry::Occupied(mut entry) => {
3631 let entry = entry.get_mut();
3632 if entry.frame_id == frame_id || entry.ref_count >= 2 {
3633 panic!("used the same element state more than once in the same frame");
3634 }
3635 entry.ref_count += 1;
3636 entry.frame_id = frame_id;
3637 }
3638 Entry::Vacant(entry) => {
3639 entry.insert(ElementStateRefCount {
3640 ref_count: 1,
3641 frame_id,
3642 });
3643 self.dropped_element_states.remove(&(tag_type_id, id));
3644 }
3645 }
3646 }
3647
3648 fn dec_model(&mut self, model_id: usize) {
3649 let count = self.entity_counts.get_mut(&model_id).unwrap();
3650 *count -= 1;
3651 if *count == 0 {
3652 self.entity_counts.remove(&model_id);
3653 self.dropped_models.insert(model_id);
3654 }
3655 }
3656
3657 fn dec_view(&mut self, window_id: usize, view_id: usize) {
3658 let count = self.entity_counts.get_mut(&view_id).unwrap();
3659 *count -= 1;
3660 if *count == 0 {
3661 self.entity_counts.remove(&view_id);
3662 self.dropped_views.insert((window_id, view_id));
3663 }
3664 }
3665
3666 fn dec_element_state(&mut self, tag_type_id: TypeId, id: ElementStateId) {
3667 let key = (tag_type_id, id);
3668 let entry = self.element_state_counts.get_mut(&key).unwrap();
3669 entry.ref_count -= 1;
3670 if entry.ref_count == 0 {
3671 self.element_state_counts.remove(&key);
3672 self.dropped_element_states.insert(key);
3673 }
3674 }
3675
3676 fn is_entity_alive(&self, entity_id: usize) -> bool {
3677 self.entity_counts.contains_key(&entity_id)
3678 }
3679
3680 fn take_dropped(
3681 &mut self,
3682 ) -> (
3683 HashSet<usize>,
3684 HashSet<(usize, usize)>,
3685 HashSet<(TypeId, ElementStateId)>,
3686 ) {
3687 (
3688 std::mem::take(&mut self.dropped_models),
3689 std::mem::take(&mut self.dropped_views),
3690 std::mem::take(&mut self.dropped_element_states),
3691 )
3692 }
3693}
3694
3695#[cfg(test)]
3696mod tests {
3697 use super::*;
3698 use crate::elements::*;
3699 use smol::future::poll_once;
3700 use std::{
3701 cell::Cell,
3702 sync::atomic::{AtomicUsize, Ordering::SeqCst},
3703 };
3704
3705 #[crate::test(self)]
3706 fn test_model_handles(cx: &mut MutableAppContext) {
3707 struct Model {
3708 other: Option<ModelHandle<Model>>,
3709 events: Vec<String>,
3710 }
3711
3712 impl Entity for Model {
3713 type Event = usize;
3714 }
3715
3716 impl Model {
3717 fn new(other: Option<ModelHandle<Self>>, cx: &mut ModelContext<Self>) -> Self {
3718 if let Some(other) = other.as_ref() {
3719 cx.observe(other, |me, _, _| {
3720 me.events.push("notified".into());
3721 })
3722 .detach();
3723 cx.subscribe(other, |me, _, event, _| {
3724 me.events.push(format!("observed event {}", event));
3725 })
3726 .detach();
3727 }
3728
3729 Self {
3730 other,
3731 events: Vec::new(),
3732 }
3733 }
3734 }
3735
3736 let handle_1 = cx.add_model(|cx| Model::new(None, cx));
3737 let handle_2 = cx.add_model(|cx| Model::new(Some(handle_1.clone()), cx));
3738 assert_eq!(cx.cx.models.len(), 2);
3739
3740 handle_1.update(cx, |model, cx| {
3741 model.events.push("updated".into());
3742 cx.emit(1);
3743 cx.notify();
3744 cx.emit(2);
3745 });
3746 assert_eq!(handle_1.read(cx).events, vec!["updated".to_string()]);
3747 assert_eq!(
3748 handle_2.read(cx).events,
3749 vec![
3750 "observed event 1".to_string(),
3751 "notified".to_string(),
3752 "observed event 2".to_string(),
3753 ]
3754 );
3755
3756 handle_2.update(cx, |model, _| {
3757 drop(handle_1);
3758 model.other.take();
3759 });
3760
3761 assert_eq!(cx.cx.models.len(), 1);
3762 assert!(cx.subscriptions.lock().is_empty());
3763 assert!(cx.observations.lock().is_empty());
3764 }
3765
3766 #[crate::test(self)]
3767 fn test_subscribe_and_emit_from_model(cx: &mut MutableAppContext) {
3768 #[derive(Default)]
3769 struct Model {
3770 events: Vec<usize>,
3771 }
3772
3773 impl Entity for Model {
3774 type Event = usize;
3775 }
3776
3777 let handle_1 = cx.add_model(|_| Model::default());
3778 let handle_2 = cx.add_model(|_| Model::default());
3779 let handle_2b = handle_2.clone();
3780
3781 handle_1.update(cx, |_, c| {
3782 c.subscribe(&handle_2, move |model: &mut Model, _, event, c| {
3783 model.events.push(*event);
3784
3785 c.subscribe(&handle_2b, |model, _, event, _| {
3786 model.events.push(*event * 2);
3787 })
3788 .detach();
3789 })
3790 .detach();
3791 });
3792
3793 handle_2.update(cx, |_, c| c.emit(7));
3794 assert_eq!(handle_1.read(cx).events, vec![7]);
3795
3796 handle_2.update(cx, |_, c| c.emit(5));
3797 assert_eq!(handle_1.read(cx).events, vec![7, 5, 10]);
3798 }
3799
3800 #[crate::test(self)]
3801 fn test_observe_and_notify_from_model(cx: &mut MutableAppContext) {
3802 #[derive(Default)]
3803 struct Model {
3804 count: usize,
3805 events: Vec<usize>,
3806 }
3807
3808 impl Entity for Model {
3809 type Event = ();
3810 }
3811
3812 let handle_1 = cx.add_model(|_| Model::default());
3813 let handle_2 = cx.add_model(|_| Model::default());
3814 let handle_2b = handle_2.clone();
3815
3816 handle_1.update(cx, |_, c| {
3817 c.observe(&handle_2, move |model, observed, c| {
3818 model.events.push(observed.read(c).count);
3819 c.observe(&handle_2b, |model, observed, c| {
3820 model.events.push(observed.read(c).count * 2);
3821 })
3822 .detach();
3823 })
3824 .detach();
3825 });
3826
3827 handle_2.update(cx, |model, c| {
3828 model.count = 7;
3829 c.notify()
3830 });
3831 assert_eq!(handle_1.read(cx).events, vec![7]);
3832
3833 handle_2.update(cx, |model, c| {
3834 model.count = 5;
3835 c.notify()
3836 });
3837 assert_eq!(handle_1.read(cx).events, vec![7, 5, 10])
3838 }
3839
3840 #[crate::test(self)]
3841 fn test_view_handles(cx: &mut MutableAppContext) {
3842 struct View {
3843 other: Option<ViewHandle<View>>,
3844 events: Vec<String>,
3845 }
3846
3847 impl Entity for View {
3848 type Event = usize;
3849 }
3850
3851 impl super::View for View {
3852 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
3853 Empty::new().boxed()
3854 }
3855
3856 fn ui_name() -> &'static str {
3857 "View"
3858 }
3859 }
3860
3861 impl View {
3862 fn new(other: Option<ViewHandle<View>>, cx: &mut ViewContext<Self>) -> Self {
3863 if let Some(other) = other.as_ref() {
3864 cx.subscribe(other, |me, _, event, _| {
3865 me.events.push(format!("observed event {}", event));
3866 })
3867 .detach();
3868 }
3869 Self {
3870 other,
3871 events: Vec::new(),
3872 }
3873 }
3874 }
3875
3876 let (window_id, _) = cx.add_window(Default::default(), |cx| View::new(None, cx));
3877 let handle_1 = cx.add_view(window_id, |cx| View::new(None, cx));
3878 let handle_2 = cx.add_view(window_id, |cx| View::new(Some(handle_1.clone()), cx));
3879 assert_eq!(cx.cx.views.len(), 3);
3880
3881 handle_1.update(cx, |view, cx| {
3882 view.events.push("updated".into());
3883 cx.emit(1);
3884 cx.emit(2);
3885 });
3886 assert_eq!(handle_1.read(cx).events, vec!["updated".to_string()]);
3887 assert_eq!(
3888 handle_2.read(cx).events,
3889 vec![
3890 "observed event 1".to_string(),
3891 "observed event 2".to_string(),
3892 ]
3893 );
3894
3895 handle_2.update(cx, |view, _| {
3896 drop(handle_1);
3897 view.other.take();
3898 });
3899
3900 assert_eq!(cx.cx.views.len(), 2);
3901 assert!(cx.subscriptions.lock().is_empty());
3902 assert!(cx.observations.lock().is_empty());
3903 }
3904
3905 #[crate::test(self)]
3906 fn test_add_window(cx: &mut MutableAppContext) {
3907 struct View {
3908 mouse_down_count: Arc<AtomicUsize>,
3909 }
3910
3911 impl Entity for View {
3912 type Event = ();
3913 }
3914
3915 impl super::View for View {
3916 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
3917 let mouse_down_count = self.mouse_down_count.clone();
3918 EventHandler::new(Empty::new().boxed())
3919 .on_mouse_down(move |_| {
3920 mouse_down_count.fetch_add(1, SeqCst);
3921 true
3922 })
3923 .boxed()
3924 }
3925
3926 fn ui_name() -> &'static str {
3927 "View"
3928 }
3929 }
3930
3931 let mouse_down_count = Arc::new(AtomicUsize::new(0));
3932 let (window_id, _) = cx.add_window(Default::default(), |_| View {
3933 mouse_down_count: mouse_down_count.clone(),
3934 });
3935 let presenter = cx.presenters_and_platform_windows[&window_id].0.clone();
3936 // Ensure window's root element is in a valid lifecycle state.
3937 presenter.borrow_mut().dispatch_event(
3938 Event::LeftMouseDown {
3939 position: Default::default(),
3940 ctrl: false,
3941 alt: false,
3942 shift: false,
3943 cmd: false,
3944 click_count: 1,
3945 },
3946 cx,
3947 );
3948 assert_eq!(mouse_down_count.load(SeqCst), 1);
3949 }
3950
3951 #[crate::test(self)]
3952 fn test_entity_release_hooks(cx: &mut MutableAppContext) {
3953 struct Model {
3954 released: Rc<Cell<bool>>,
3955 }
3956
3957 struct View {
3958 released: Rc<Cell<bool>>,
3959 }
3960
3961 impl Entity for Model {
3962 type Event = ();
3963
3964 fn release(&mut self, _: &mut MutableAppContext) {
3965 self.released.set(true);
3966 }
3967 }
3968
3969 impl Entity for View {
3970 type Event = ();
3971
3972 fn release(&mut self, _: &mut MutableAppContext) {
3973 self.released.set(true);
3974 }
3975 }
3976
3977 impl super::View for View {
3978 fn ui_name() -> &'static str {
3979 "View"
3980 }
3981
3982 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
3983 Empty::new().boxed()
3984 }
3985 }
3986
3987 let model_released = Rc::new(Cell::new(false));
3988 let model_release_observed = Rc::new(Cell::new(false));
3989 let view_released = Rc::new(Cell::new(false));
3990 let view_release_observed = Rc::new(Cell::new(false));
3991
3992 let model = cx.add_model(|_| Model {
3993 released: model_released.clone(),
3994 });
3995 let (window_id, view) = cx.add_window(Default::default(), |_| View {
3996 released: view_released.clone(),
3997 });
3998 assert!(!model_released.get());
3999 assert!(!view_released.get());
4000
4001 cx.observe_release(&model, {
4002 let model_release_observed = model_release_observed.clone();
4003 move |_| model_release_observed.set(true)
4004 })
4005 .detach();
4006 cx.observe_release(&view, {
4007 let view_release_observed = view_release_observed.clone();
4008 move |_| view_release_observed.set(true)
4009 })
4010 .detach();
4011
4012 cx.update(move |_| {
4013 drop(model);
4014 });
4015 assert!(model_released.get());
4016 assert!(model_release_observed.get());
4017
4018 drop(view);
4019 cx.remove_window(window_id);
4020 assert!(view_released.get());
4021 assert!(view_release_observed.get());
4022 }
4023
4024 #[crate::test(self)]
4025 fn test_subscribe_and_emit_from_view(cx: &mut MutableAppContext) {
4026 #[derive(Default)]
4027 struct View {
4028 events: Vec<usize>,
4029 }
4030
4031 impl Entity for View {
4032 type Event = usize;
4033 }
4034
4035 impl super::View for View {
4036 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4037 Empty::new().boxed()
4038 }
4039
4040 fn ui_name() -> &'static str {
4041 "View"
4042 }
4043 }
4044
4045 struct Model;
4046
4047 impl Entity for Model {
4048 type Event = usize;
4049 }
4050
4051 let (window_id, handle_1) = cx.add_window(Default::default(), |_| View::default());
4052 let handle_2 = cx.add_view(window_id, |_| View::default());
4053 let handle_2b = handle_2.clone();
4054 let handle_3 = cx.add_model(|_| Model);
4055
4056 handle_1.update(cx, |_, c| {
4057 c.subscribe(&handle_2, move |me, _, event, c| {
4058 me.events.push(*event);
4059
4060 c.subscribe(&handle_2b, |me, _, event, _| {
4061 me.events.push(*event * 2);
4062 })
4063 .detach();
4064 })
4065 .detach();
4066
4067 c.subscribe(&handle_3, |me, _, event, _| {
4068 me.events.push(*event);
4069 })
4070 .detach();
4071 });
4072
4073 handle_2.update(cx, |_, c| c.emit(7));
4074 assert_eq!(handle_1.read(cx).events, vec![7]);
4075
4076 handle_2.update(cx, |_, c| c.emit(5));
4077 assert_eq!(handle_1.read(cx).events, vec![7, 5, 10]);
4078
4079 handle_3.update(cx, |_, c| c.emit(9));
4080 assert_eq!(handle_1.read(cx).events, vec![7, 5, 10, 9]);
4081 }
4082
4083 #[crate::test(self)]
4084 fn test_dropping_subscribers(cx: &mut MutableAppContext) {
4085 struct View;
4086
4087 impl Entity for View {
4088 type Event = ();
4089 }
4090
4091 impl super::View for View {
4092 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4093 Empty::new().boxed()
4094 }
4095
4096 fn ui_name() -> &'static str {
4097 "View"
4098 }
4099 }
4100
4101 struct Model;
4102
4103 impl Entity for Model {
4104 type Event = ();
4105 }
4106
4107 let (window_id, _) = cx.add_window(Default::default(), |_| View);
4108 let observing_view = cx.add_view(window_id, |_| View);
4109 let emitting_view = cx.add_view(window_id, |_| View);
4110 let observing_model = cx.add_model(|_| Model);
4111 let observed_model = cx.add_model(|_| Model);
4112
4113 observing_view.update(cx, |_, cx| {
4114 cx.subscribe(&emitting_view, |_, _, _, _| {}).detach();
4115 cx.subscribe(&observed_model, |_, _, _, _| {}).detach();
4116 });
4117 observing_model.update(cx, |_, cx| {
4118 cx.subscribe(&observed_model, |_, _, _, _| {}).detach();
4119 });
4120
4121 cx.update(|_| {
4122 drop(observing_view);
4123 drop(observing_model);
4124 });
4125
4126 emitting_view.update(cx, |_, cx| cx.emit(()));
4127 observed_model.update(cx, |_, cx| cx.emit(()));
4128 }
4129
4130 #[crate::test(self)]
4131 fn test_observe_and_notify_from_view(cx: &mut MutableAppContext) {
4132 #[derive(Default)]
4133 struct View {
4134 events: Vec<usize>,
4135 }
4136
4137 impl Entity for View {
4138 type Event = usize;
4139 }
4140
4141 impl super::View for View {
4142 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4143 Empty::new().boxed()
4144 }
4145
4146 fn ui_name() -> &'static str {
4147 "View"
4148 }
4149 }
4150
4151 #[derive(Default)]
4152 struct Model {
4153 count: usize,
4154 }
4155
4156 impl Entity for Model {
4157 type Event = ();
4158 }
4159
4160 let (_, view) = cx.add_window(Default::default(), |_| View::default());
4161 let model = cx.add_model(|_| Model::default());
4162
4163 view.update(cx, |_, c| {
4164 c.observe(&model, |me, observed, c| {
4165 me.events.push(observed.read(c).count)
4166 })
4167 .detach();
4168 });
4169
4170 model.update(cx, |model, c| {
4171 model.count = 11;
4172 c.notify();
4173 });
4174 assert_eq!(view.read(cx).events, vec![11]);
4175 }
4176
4177 #[crate::test(self)]
4178 fn test_dropping_observers(cx: &mut MutableAppContext) {
4179 struct View;
4180
4181 impl Entity for View {
4182 type Event = ();
4183 }
4184
4185 impl super::View for View {
4186 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4187 Empty::new().boxed()
4188 }
4189
4190 fn ui_name() -> &'static str {
4191 "View"
4192 }
4193 }
4194
4195 struct Model;
4196
4197 impl Entity for Model {
4198 type Event = ();
4199 }
4200
4201 let (window_id, _) = cx.add_window(Default::default(), |_| View);
4202 let observing_view = cx.add_view(window_id, |_| View);
4203 let observing_model = cx.add_model(|_| Model);
4204 let observed_model = cx.add_model(|_| Model);
4205
4206 observing_view.update(cx, |_, cx| {
4207 cx.observe(&observed_model, |_, _, _| {}).detach();
4208 });
4209 observing_model.update(cx, |_, cx| {
4210 cx.observe(&observed_model, |_, _, _| {}).detach();
4211 });
4212
4213 cx.update(|_| {
4214 drop(observing_view);
4215 drop(observing_model);
4216 });
4217
4218 observed_model.update(cx, |_, cx| cx.notify());
4219 }
4220
4221 #[crate::test(self)]
4222 fn test_focus(cx: &mut MutableAppContext) {
4223 struct View {
4224 name: String,
4225 events: Arc<Mutex<Vec<String>>>,
4226 }
4227
4228 impl Entity for View {
4229 type Event = ();
4230 }
4231
4232 impl super::View for View {
4233 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4234 Empty::new().boxed()
4235 }
4236
4237 fn ui_name() -> &'static str {
4238 "View"
4239 }
4240
4241 fn on_focus(&mut self, _: &mut ViewContext<Self>) {
4242 self.events.lock().push(format!("{} focused", &self.name));
4243 }
4244
4245 fn on_blur(&mut self, _: &mut ViewContext<Self>) {
4246 self.events.lock().push(format!("{} blurred", &self.name));
4247 }
4248 }
4249
4250 let events: Arc<Mutex<Vec<String>>> = Default::default();
4251 let (window_id, view_1) = cx.add_window(Default::default(), |_| View {
4252 events: events.clone(),
4253 name: "view 1".to_string(),
4254 });
4255 let view_2 = cx.add_view(window_id, |_| View {
4256 events: events.clone(),
4257 name: "view 2".to_string(),
4258 });
4259
4260 view_1.update(cx, |_, cx| cx.focus(&view_2));
4261 view_1.update(cx, |_, cx| cx.focus(&view_1));
4262 view_1.update(cx, |_, cx| cx.focus(&view_2));
4263 view_1.update(cx, |_, _| drop(view_2));
4264
4265 assert_eq!(
4266 *events.lock(),
4267 [
4268 "view 1 focused".to_string(),
4269 "view 1 blurred".to_string(),
4270 "view 2 focused".to_string(),
4271 "view 2 blurred".to_string(),
4272 "view 1 focused".to_string(),
4273 "view 1 blurred".to_string(),
4274 "view 2 focused".to_string(),
4275 "view 1 focused".to_string(),
4276 ],
4277 );
4278 }
4279
4280 #[crate::test(self)]
4281 fn test_dispatch_action(cx: &mut MutableAppContext) {
4282 struct ViewA {
4283 id: usize,
4284 }
4285
4286 impl Entity for ViewA {
4287 type Event = ();
4288 }
4289
4290 impl View for ViewA {
4291 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4292 Empty::new().boxed()
4293 }
4294
4295 fn ui_name() -> &'static str {
4296 "View"
4297 }
4298 }
4299
4300 struct ViewB {
4301 id: usize,
4302 }
4303
4304 impl Entity for ViewB {
4305 type Event = ();
4306 }
4307
4308 impl View for ViewB {
4309 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4310 Empty::new().boxed()
4311 }
4312
4313 fn ui_name() -> &'static str {
4314 "View"
4315 }
4316 }
4317
4318 action!(Action, &'static str);
4319
4320 let actions = Rc::new(RefCell::new(Vec::new()));
4321
4322 let actions_clone = actions.clone();
4323 cx.add_global_action(move |_: &Action, _: &mut MutableAppContext| {
4324 actions_clone.borrow_mut().push("global".to_string());
4325 });
4326
4327 let actions_clone = actions.clone();
4328 cx.add_action(move |view: &mut ViewA, action: &Action, cx| {
4329 assert_eq!(action.0, "bar");
4330 cx.propagate_action();
4331 actions_clone.borrow_mut().push(format!("{} a", view.id));
4332 });
4333
4334 let actions_clone = actions.clone();
4335 cx.add_action(move |view: &mut ViewA, _: &Action, cx| {
4336 if view.id != 1 {
4337 cx.propagate_action();
4338 }
4339 actions_clone.borrow_mut().push(format!("{} b", view.id));
4340 });
4341
4342 let actions_clone = actions.clone();
4343 cx.add_action(move |view: &mut ViewB, _: &Action, cx| {
4344 cx.propagate_action();
4345 actions_clone.borrow_mut().push(format!("{} c", view.id));
4346 });
4347
4348 let actions_clone = actions.clone();
4349 cx.add_action(move |view: &mut ViewB, _: &Action, cx| {
4350 cx.propagate_action();
4351 actions_clone.borrow_mut().push(format!("{} d", view.id));
4352 });
4353
4354 let (window_id, view_1) = cx.add_window(Default::default(), |_| ViewA { id: 1 });
4355 let view_2 = cx.add_view(window_id, |_| ViewB { id: 2 });
4356 let view_3 = cx.add_view(window_id, |_| ViewA { id: 3 });
4357 let view_4 = cx.add_view(window_id, |_| ViewB { id: 4 });
4358
4359 cx.dispatch_action(
4360 window_id,
4361 vec![view_1.id(), view_2.id(), view_3.id(), view_4.id()],
4362 &Action("bar"),
4363 );
4364
4365 assert_eq!(
4366 *actions.borrow(),
4367 vec!["4 d", "4 c", "3 b", "3 a", "2 d", "2 c", "1 b"]
4368 );
4369
4370 // Remove view_1, which doesn't propagate the action
4371 actions.borrow_mut().clear();
4372 cx.dispatch_action(
4373 window_id,
4374 vec![view_2.id(), view_3.id(), view_4.id()],
4375 &Action("bar"),
4376 );
4377
4378 assert_eq!(
4379 *actions.borrow(),
4380 vec!["4 d", "4 c", "3 b", "3 a", "2 d", "2 c", "global"]
4381 );
4382 }
4383
4384 #[crate::test(self)]
4385 fn test_dispatch_keystroke(cx: &mut MutableAppContext) {
4386 use std::cell::Cell;
4387
4388 action!(Action, &'static str);
4389
4390 struct View {
4391 id: usize,
4392 keymap_context: keymap::Context,
4393 }
4394
4395 impl Entity for View {
4396 type Event = ();
4397 }
4398
4399 impl super::View for View {
4400 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4401 Empty::new().boxed()
4402 }
4403
4404 fn ui_name() -> &'static str {
4405 "View"
4406 }
4407
4408 fn keymap_context(&self, _: &AppContext) -> keymap::Context {
4409 self.keymap_context.clone()
4410 }
4411 }
4412
4413 impl View {
4414 fn new(id: usize) -> Self {
4415 View {
4416 id,
4417 keymap_context: keymap::Context::default(),
4418 }
4419 }
4420 }
4421
4422 let mut view_1 = View::new(1);
4423 let mut view_2 = View::new(2);
4424 let mut view_3 = View::new(3);
4425 view_1.keymap_context.set.insert("a".into());
4426 view_2.keymap_context.set.insert("a".into());
4427 view_2.keymap_context.set.insert("b".into());
4428 view_3.keymap_context.set.insert("a".into());
4429 view_3.keymap_context.set.insert("b".into());
4430 view_3.keymap_context.set.insert("c".into());
4431
4432 let (window_id, view_1) = cx.add_window(Default::default(), |_| view_1);
4433 let view_2 = cx.add_view(window_id, |_| view_2);
4434 let view_3 = cx.add_view(window_id, |_| view_3);
4435
4436 // This keymap's only binding dispatches an action on view 2 because that view will have
4437 // "a" and "b" in its context, but not "c".
4438 cx.add_bindings(vec![keymap::Binding::new(
4439 "a",
4440 Action("a"),
4441 Some("a && b && !c"),
4442 )]);
4443
4444 let handled_action = Rc::new(Cell::new(false));
4445 let handled_action_clone = handled_action.clone();
4446 cx.add_action(move |view: &mut View, action: &Action, _| {
4447 handled_action_clone.set(true);
4448 assert_eq!(view.id, 2);
4449 assert_eq!(action.0, "a");
4450 });
4451
4452 cx.dispatch_keystroke(
4453 window_id,
4454 vec![view_1.id(), view_2.id(), view_3.id()],
4455 &Keystroke::parse("a").unwrap(),
4456 )
4457 .unwrap();
4458
4459 assert!(handled_action.get());
4460 }
4461
4462 #[crate::test(self)]
4463 async fn test_model_condition(mut cx: TestAppContext) {
4464 struct Counter(usize);
4465
4466 impl super::Entity for Counter {
4467 type Event = ();
4468 }
4469
4470 impl Counter {
4471 fn inc(&mut self, cx: &mut ModelContext<Self>) {
4472 self.0 += 1;
4473 cx.notify();
4474 }
4475 }
4476
4477 let model = cx.add_model(|_| Counter(0));
4478
4479 let condition1 = model.condition(&cx, |model, _| model.0 == 2);
4480 let condition2 = model.condition(&cx, |model, _| model.0 == 3);
4481 smol::pin!(condition1, condition2);
4482
4483 model.update(&mut cx, |model, cx| model.inc(cx));
4484 assert_eq!(poll_once(&mut condition1).await, None);
4485 assert_eq!(poll_once(&mut condition2).await, None);
4486
4487 model.update(&mut cx, |model, cx| model.inc(cx));
4488 assert_eq!(poll_once(&mut condition1).await, Some(()));
4489 assert_eq!(poll_once(&mut condition2).await, None);
4490
4491 model.update(&mut cx, |model, cx| model.inc(cx));
4492 assert_eq!(poll_once(&mut condition2).await, Some(()));
4493
4494 model.update(&mut cx, |_, cx| cx.notify());
4495 }
4496
4497 #[crate::test(self)]
4498 #[should_panic]
4499 async fn test_model_condition_timeout(mut cx: TestAppContext) {
4500 struct Model;
4501
4502 impl super::Entity for Model {
4503 type Event = ();
4504 }
4505
4506 let model = cx.add_model(|_| Model);
4507 model.condition(&cx, |_, _| false).await;
4508 }
4509
4510 #[crate::test(self)]
4511 #[should_panic(expected = "model dropped with pending condition")]
4512 async fn test_model_condition_panic_on_drop(mut cx: TestAppContext) {
4513 struct Model;
4514
4515 impl super::Entity for Model {
4516 type Event = ();
4517 }
4518
4519 let model = cx.add_model(|_| Model);
4520 let condition = model.condition(&cx, |_, _| false);
4521 cx.update(|_| drop(model));
4522 condition.await;
4523 }
4524
4525 #[crate::test(self)]
4526 async fn test_view_condition(mut cx: TestAppContext) {
4527 struct Counter(usize);
4528
4529 impl super::Entity for Counter {
4530 type Event = ();
4531 }
4532
4533 impl super::View for Counter {
4534 fn ui_name() -> &'static str {
4535 "test view"
4536 }
4537
4538 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4539 Empty::new().boxed()
4540 }
4541 }
4542
4543 impl Counter {
4544 fn inc(&mut self, cx: &mut ViewContext<Self>) {
4545 self.0 += 1;
4546 cx.notify();
4547 }
4548 }
4549
4550 let (_, view) = cx.add_window(|_| Counter(0));
4551
4552 let condition1 = view.condition(&cx, |view, _| view.0 == 2);
4553 let condition2 = view.condition(&cx, |view, _| view.0 == 3);
4554 smol::pin!(condition1, condition2);
4555
4556 view.update(&mut cx, |view, cx| view.inc(cx));
4557 assert_eq!(poll_once(&mut condition1).await, None);
4558 assert_eq!(poll_once(&mut condition2).await, None);
4559
4560 view.update(&mut cx, |view, cx| view.inc(cx));
4561 assert_eq!(poll_once(&mut condition1).await, Some(()));
4562 assert_eq!(poll_once(&mut condition2).await, None);
4563
4564 view.update(&mut cx, |view, cx| view.inc(cx));
4565 assert_eq!(poll_once(&mut condition2).await, Some(()));
4566 view.update(&mut cx, |_, cx| cx.notify());
4567 }
4568
4569 #[crate::test(self)]
4570 #[should_panic]
4571 async fn test_view_condition_timeout(mut cx: TestAppContext) {
4572 struct View;
4573
4574 impl super::Entity for View {
4575 type Event = ();
4576 }
4577
4578 impl super::View for View {
4579 fn ui_name() -> &'static str {
4580 "test view"
4581 }
4582
4583 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4584 Empty::new().boxed()
4585 }
4586 }
4587
4588 let (_, view) = cx.add_window(|_| View);
4589 view.condition(&cx, |_, _| false).await;
4590 }
4591
4592 #[crate::test(self)]
4593 #[should_panic(expected = "view dropped with pending condition")]
4594 async fn test_view_condition_panic_on_drop(mut cx: TestAppContext) {
4595 struct View;
4596
4597 impl super::Entity for View {
4598 type Event = ();
4599 }
4600
4601 impl super::View for View {
4602 fn ui_name() -> &'static str {
4603 "test view"
4604 }
4605
4606 fn render(&mut self, _: &mut RenderContext<Self>) -> ElementBox {
4607 Empty::new().boxed()
4608 }
4609 }
4610
4611 let window_id = cx.add_window(|_| View).0;
4612 let view = cx.add_view(window_id, |_| View);
4613
4614 let condition = view.condition(&cx, |_, _| false);
4615 cx.update(|_| drop(view));
4616 condition.await;
4617 }
4618}