1mod async_context;
2mod entity_map;
3mod model_context;
4#[cfg(any(test, feature = "test-support"))]
5mod test_context;
6
7pub use async_context::*;
8pub use entity_map::*;
9pub use model_context::*;
10use refineable::Refineable;
11use smallvec::SmallVec;
12#[cfg(any(test, feature = "test-support"))]
13pub use test_context::*;
14
15use crate::{
16 current_platform, image_cache::ImageCache, Action, AnyBox, AnyView, AppMetadata, AssetSource,
17 ClipboardItem, Context, DispatchPhase, DisplayId, Executor, FocusEvent, FocusHandle, FocusId,
18 KeyBinding, Keymap, LayoutId, MainThread, MainThreadOnly, Pixels, Platform, Point,
19 SharedString, SubscriberSet, Subscription, SvgRenderer, Task, TextStyle, TextStyleRefinement,
20 TextSystem, View, Window, WindowContext, WindowHandle, WindowId,
21};
22use anyhow::{anyhow, Result};
23use collections::{HashMap, HashSet, VecDeque};
24use futures::{future::BoxFuture, Future};
25use parking_lot::{Mutex, RwLock};
26use slotmap::SlotMap;
27use std::{
28 any::{type_name, Any, TypeId},
29 borrow::Borrow,
30 marker::PhantomData,
31 mem,
32 ops::{Deref, DerefMut},
33 path::PathBuf,
34 sync::{atomic::Ordering::SeqCst, Arc, Weak},
35 time::Duration,
36};
37use util::http::{self, HttpClient};
38
39pub struct App(Arc<Mutex<AppContext>>);
40
41impl App {
42 pub fn production(asset_source: Arc<dyn AssetSource>) -> Self {
43 Self(AppContext::new(
44 current_platform(),
45 asset_source,
46 http::client(),
47 ))
48 }
49
50 pub fn run<F>(self, on_finish_launching: F)
51 where
52 F: 'static + FnOnce(&mut MainThread<AppContext>),
53 {
54 let this = self.0.clone();
55 let platform = self.0.lock().platform.clone();
56 platform.borrow_on_main_thread().run(Box::new(move || {
57 let cx = &mut *this.lock();
58 let cx = unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) };
59 on_finish_launching(cx);
60 }));
61 }
62
63 pub fn on_open_urls<F>(&self, mut callback: F) -> &Self
64 where
65 F: 'static + FnMut(Vec<String>, &mut AppContext),
66 {
67 let this = Arc::downgrade(&self.0);
68 self.0
69 .lock()
70 .platform
71 .borrow_on_main_thread()
72 .on_open_urls(Box::new(move |urls| {
73 if let Some(app) = this.upgrade() {
74 callback(urls, &mut app.lock());
75 }
76 }));
77 self
78 }
79
80 pub fn on_reopen<F>(&self, mut callback: F) -> &Self
81 where
82 F: 'static + FnMut(&mut AppContext),
83 {
84 let this = Arc::downgrade(&self.0);
85 self.0
86 .lock()
87 .platform
88 .borrow_on_main_thread()
89 .on_reopen(Box::new(move || {
90 if let Some(app) = this.upgrade() {
91 callback(&mut app.lock());
92 }
93 }));
94 self
95 }
96
97 pub fn metadata(&self) -> AppMetadata {
98 self.0.lock().app_metadata.clone()
99 }
100
101 pub fn executor(&self) -> Executor {
102 self.0.lock().executor.clone()
103 }
104
105 pub fn text_system(&self) -> Arc<TextSystem> {
106 self.0.lock().text_system.clone()
107 }
108}
109
110type ActionBuilder = fn(json: Option<serde_json::Value>) -> anyhow::Result<Box<dyn Action>>;
111type FrameCallback = Box<dyn FnOnce(&mut WindowContext) + Send>;
112type Handler = Box<dyn FnMut(&mut AppContext) -> bool + Send + Sync + 'static>;
113type Listener = Box<dyn FnMut(&dyn Any, &mut AppContext) -> bool + Send + Sync + 'static>;
114type QuitHandler =
115 Box<dyn FnMut(&mut AppContext) -> BoxFuture<'static, ()> + Send + Sync + 'static>;
116type ReleaseListener = Box<dyn FnMut(&mut dyn Any, &mut AppContext) + Send + Sync + 'static>;
117
118pub struct AppContext {
119 this: Weak<Mutex<AppContext>>,
120 pub(crate) platform: MainThreadOnly<dyn Platform>,
121 app_metadata: AppMetadata,
122 text_system: Arc<TextSystem>,
123 flushing_effects: bool,
124 pending_updates: usize,
125 pub(crate) active_drag: Option<AnyDrag>,
126 pub(crate) next_frame_callbacks: HashMap<DisplayId, Vec<FrameCallback>>,
127 pub(crate) executor: Executor,
128 pub(crate) svg_renderer: SvgRenderer,
129 asset_source: Arc<dyn AssetSource>,
130 pub(crate) image_cache: ImageCache,
131 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
132 pub(crate) globals_by_type: HashMap<TypeId, AnyBox>,
133 pub(crate) unit_entity: Handle<()>,
134 pub(crate) entities: EntityMap,
135 pub(crate) windows: SlotMap<WindowId, Option<Window>>,
136 pub(crate) keymap: Arc<RwLock<Keymap>>,
137 pub(crate) global_action_listeners:
138 HashMap<TypeId, Vec<Box<dyn Fn(&dyn Action, DispatchPhase, &mut Self) + Send + Sync>>>,
139 action_builders: HashMap<SharedString, ActionBuilder>,
140 pending_effects: VecDeque<Effect>,
141 pub(crate) pending_notifications: HashSet<EntityId>,
142 pub(crate) pending_global_notifications: HashSet<TypeId>,
143 pub(crate) observers: SubscriberSet<EntityId, Handler>,
144 pub(crate) event_listeners: SubscriberSet<EntityId, Listener>,
145 pub(crate) release_listeners: SubscriberSet<EntityId, ReleaseListener>,
146 pub(crate) global_observers: SubscriberSet<TypeId, Handler>,
147 pub(crate) quit_observers: SubscriberSet<(), QuitHandler>,
148 pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
149 pub(crate) propagate_event: bool,
150}
151
152impl AppContext {
153 pub(crate) fn new(
154 platform: Arc<dyn Platform>,
155 asset_source: Arc<dyn AssetSource>,
156 http_client: Arc<dyn HttpClient>,
157 ) -> Arc<Mutex<Self>> {
158 let executor = platform.executor();
159 assert!(
160 executor.is_main_thread(),
161 "must construct App on main thread"
162 );
163
164 let text_system = Arc::new(TextSystem::new(platform.text_system()));
165 let mut entities = EntityMap::new();
166 let unit_entity = entities.insert(entities.reserve(), ());
167 let app_metadata = AppMetadata {
168 os_name: platform.os_name(),
169 os_version: platform.os_version().ok(),
170 app_version: platform.app_version().ok(),
171 };
172
173 Arc::new_cyclic(|this| {
174 Mutex::new(AppContext {
175 this: this.clone(),
176 text_system,
177 platform: MainThreadOnly::new(platform, executor.clone()),
178 app_metadata,
179 flushing_effects: false,
180 pending_updates: 0,
181 next_frame_callbacks: Default::default(),
182 executor,
183 svg_renderer: SvgRenderer::new(asset_source.clone()),
184 asset_source,
185 image_cache: ImageCache::new(http_client),
186 text_style_stack: Vec::new(),
187 globals_by_type: HashMap::default(),
188 unit_entity,
189 entities,
190 windows: SlotMap::with_key(),
191 keymap: Arc::new(RwLock::new(Keymap::default())),
192 global_action_listeners: HashMap::default(),
193 action_builders: HashMap::default(),
194 pending_effects: VecDeque::new(),
195 pending_notifications: HashSet::default(),
196 pending_global_notifications: HashSet::default(),
197 observers: SubscriberSet::new(),
198 event_listeners: SubscriberSet::new(),
199 release_listeners: SubscriberSet::new(),
200 global_observers: SubscriberSet::new(),
201 quit_observers: SubscriberSet::new(),
202 layout_id_buffer: Default::default(),
203 propagate_event: true,
204 active_drag: None,
205 })
206 })
207 }
208
209 pub fn quit(&mut self) {
210 let mut futures = Vec::new();
211
212 self.quit_observers.clone().retain(&(), |observer| {
213 futures.push(observer(self));
214 true
215 });
216
217 self.windows.clear();
218 self.flush_effects();
219
220 let futures = futures::future::join_all(futures);
221 if self
222 .executor
223 .block_with_timeout(Duration::from_millis(100), futures)
224 .is_err()
225 {
226 log::error!("timed out waiting on app_will_quit");
227 }
228
229 self.globals_by_type.clear();
230 }
231
232 pub fn app_metadata(&self) -> AppMetadata {
233 self.app_metadata.clone()
234 }
235
236 pub fn refresh(&mut self) {
237 self.pending_effects.push_back(Effect::Refresh);
238 }
239
240 pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
241 self.pending_updates += 1;
242 let result = update(self);
243 if !self.flushing_effects && self.pending_updates == 1 {
244 self.flushing_effects = true;
245 self.flush_effects();
246 self.flushing_effects = false;
247 }
248 self.pending_updates -= 1;
249 result
250 }
251
252 pub(crate) fn read_window<R>(
253 &mut self,
254 id: WindowId,
255 read: impl FnOnce(&WindowContext) -> R,
256 ) -> Result<R> {
257 let window = self
258 .windows
259 .get(id)
260 .ok_or_else(|| anyhow!("window not found"))?
261 .as_ref()
262 .unwrap();
263 Ok(read(&WindowContext::immutable(self, &window)))
264 }
265
266 pub(crate) fn update_window<R>(
267 &mut self,
268 id: WindowId,
269 update: impl FnOnce(&mut WindowContext) -> R,
270 ) -> Result<R> {
271 self.update(|cx| {
272 let mut window = cx
273 .windows
274 .get_mut(id)
275 .ok_or_else(|| anyhow!("window not found"))?
276 .take()
277 .unwrap();
278
279 let result = update(&mut WindowContext::mutable(cx, &mut window));
280
281 cx.windows
282 .get_mut(id)
283 .ok_or_else(|| anyhow!("window not found"))?
284 .replace(window);
285
286 Ok(result)
287 })
288 }
289
290 pub(crate) fn push_effect(&mut self, effect: Effect) {
291 match &effect {
292 Effect::Notify { emitter } => {
293 if !self.pending_notifications.insert(*emitter) {
294 return;
295 }
296 }
297 Effect::NotifyGlobalObservers { global_type } => {
298 if !self.pending_global_notifications.insert(*global_type) {
299 return;
300 }
301 }
302 _ => {}
303 };
304
305 self.pending_effects.push_back(effect);
306 }
307
308 fn flush_effects(&mut self) {
309 loop {
310 self.release_dropped_entities();
311 self.release_dropped_focus_handles();
312 if let Some(effect) = self.pending_effects.pop_front() {
313 match effect {
314 Effect::Notify { emitter } => {
315 self.apply_notify_effect(emitter);
316 }
317 Effect::Emit { emitter, event } => self.apply_emit_effect(emitter, event),
318 Effect::FocusChanged { window_id, focused } => {
319 self.apply_focus_changed_effect(window_id, focused);
320 }
321 Effect::Refresh => {
322 self.apply_refresh_effect();
323 }
324 Effect::NotifyGlobalObservers { global_type } => {
325 self.apply_notify_global_observers_effect(global_type);
326 }
327 Effect::Defer { callback } => {
328 self.apply_defer_effect(callback);
329 }
330 }
331 } else {
332 break;
333 }
334 }
335
336 let dirty_window_ids = self
337 .windows
338 .iter()
339 .filter_map(|(window_id, window)| {
340 let window = window.as_ref().unwrap();
341 if window.dirty {
342 Some(window_id)
343 } else {
344 None
345 }
346 })
347 .collect::<SmallVec<[_; 8]>>();
348
349 for dirty_window_id in dirty_window_ids {
350 self.update_window(dirty_window_id, |cx| cx.draw()).unwrap();
351 }
352 }
353
354 fn release_dropped_entities(&mut self) {
355 loop {
356 let dropped = self.entities.take_dropped();
357 if dropped.is_empty() {
358 break;
359 }
360
361 for (entity_id, mut entity) in dropped {
362 self.observers.remove(&entity_id);
363 self.event_listeners.remove(&entity_id);
364 for mut release_callback in self.release_listeners.remove(&entity_id) {
365 release_callback(entity.as_mut(), self);
366 }
367 }
368 }
369 }
370
371 fn release_dropped_focus_handles(&mut self) {
372 let window_ids = self.windows.keys().collect::<SmallVec<[_; 8]>>();
373 for window_id in window_ids {
374 self.update_window(window_id, |cx| {
375 let mut blur_window = false;
376 let focus = cx.window.focus;
377 cx.window.focus_handles.write().retain(|handle_id, count| {
378 if count.load(SeqCst) == 0 {
379 if focus == Some(handle_id) {
380 blur_window = true;
381 }
382 false
383 } else {
384 true
385 }
386 });
387
388 if blur_window {
389 cx.blur();
390 }
391 })
392 .unwrap();
393 }
394 }
395
396 fn apply_notify_effect(&mut self, emitter: EntityId) {
397 self.pending_notifications.remove(&emitter);
398 self.observers
399 .clone()
400 .retain(&emitter, |handler| handler(self));
401 }
402
403 fn apply_emit_effect(&mut self, emitter: EntityId, event: Box<dyn Any>) {
404 self.event_listeners
405 .clone()
406 .retain(&emitter, |handler| handler(event.as_ref(), self));
407 }
408
409 fn apply_focus_changed_effect(&mut self, window_id: WindowId, focused: Option<FocusId>) {
410 self.update_window(window_id, |cx| {
411 if cx.window.focus == focused {
412 let mut listeners = mem::take(&mut cx.window.focus_listeners);
413 let focused =
414 focused.map(|id| FocusHandle::for_id(id, &cx.window.focus_handles).unwrap());
415 let blurred = cx
416 .window
417 .last_blur
418 .take()
419 .unwrap()
420 .and_then(|id| FocusHandle::for_id(id, &cx.window.focus_handles));
421 if focused.is_some() || blurred.is_some() {
422 let event = FocusEvent { focused, blurred };
423 for listener in &listeners {
424 listener(&event, cx);
425 }
426 }
427
428 listeners.extend(cx.window.focus_listeners.drain(..));
429 cx.window.focus_listeners = listeners;
430 }
431 })
432 .ok();
433 }
434
435 fn apply_refresh_effect(&mut self) {
436 for window in self.windows.values_mut() {
437 if let Some(window) = window.as_mut() {
438 window.dirty = true;
439 }
440 }
441 }
442
443 fn apply_notify_global_observers_effect(&mut self, type_id: TypeId) {
444 self.pending_global_notifications.remove(&type_id);
445 self.global_observers
446 .clone()
447 .retain(&type_id, |observer| observer(self));
448 }
449
450 fn apply_defer_effect(&mut self, callback: Box<dyn FnOnce(&mut Self) + Send + Sync + 'static>) {
451 callback(self);
452 }
453
454 pub fn to_async(&self) -> AsyncAppContext {
455 AsyncAppContext {
456 app: unsafe { mem::transmute(self.this.clone()) },
457 executor: self.executor.clone(),
458 }
459 }
460
461 pub fn executor(&self) -> &Executor {
462 &self.executor
463 }
464
465 pub fn run_on_main<R>(
466 &mut self,
467 f: impl FnOnce(&mut MainThread<AppContext>) -> R + Send + 'static,
468 ) -> Task<R>
469 where
470 R: Send + 'static,
471 {
472 if self.executor.is_main_thread() {
473 Task::ready(f(unsafe {
474 mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(self)
475 }))
476 } else {
477 let this = self.this.upgrade().unwrap();
478 self.executor.run_on_main(move || {
479 let cx = &mut *this.lock();
480 cx.update(|cx| f(unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(cx) }))
481 })
482 }
483 }
484
485 pub fn spawn_on_main<F, R>(
486 &self,
487 f: impl FnOnce(MainThread<AsyncAppContext>) -> F + Send + 'static,
488 ) -> Task<R>
489 where
490 F: Future<Output = R> + 'static,
491 R: Send + 'static,
492 {
493 let cx = self.to_async();
494 self.executor.spawn_on_main(move || f(MainThread(cx)))
495 }
496
497 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncAppContext) -> Fut + Send + 'static) -> Task<R>
498 where
499 Fut: Future<Output = R> + Send + 'static,
500 R: Send + 'static,
501 {
502 let cx = self.to_async();
503 self.executor.spawn(async move {
504 let future = f(cx);
505 future.await
506 })
507 }
508
509 pub fn defer(&mut self, f: impl FnOnce(&mut AppContext) + 'static + Send + Sync) {
510 self.push_effect(Effect::Defer {
511 callback: Box::new(f),
512 });
513 }
514
515 pub fn asset_source(&self) -> &Arc<dyn AssetSource> {
516 &self.asset_source
517 }
518
519 pub fn text_system(&self) -> &Arc<TextSystem> {
520 &self.text_system
521 }
522
523 pub fn text_style(&self) -> TextStyle {
524 let mut style = TextStyle::default();
525 for refinement in &self.text_style_stack {
526 style.refine(refinement);
527 }
528 style
529 }
530
531 pub fn has_global<G: 'static>(&self) -> bool {
532 self.globals_by_type.contains_key(&TypeId::of::<G>())
533 }
534
535 pub fn global<G: 'static>(&self) -> &G {
536 self.globals_by_type
537 .get(&TypeId::of::<G>())
538 .map(|any_state| any_state.downcast_ref::<G>().unwrap())
539 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
540 .unwrap()
541 }
542
543 pub fn try_global<G: 'static>(&self) -> Option<&G> {
544 self.globals_by_type
545 .get(&TypeId::of::<G>())
546 .map(|any_state| any_state.downcast_ref::<G>().unwrap())
547 }
548
549 pub fn global_mut<G: 'static>(&mut self) -> &mut G {
550 let global_type = TypeId::of::<G>();
551 self.push_effect(Effect::NotifyGlobalObservers { global_type });
552 self.globals_by_type
553 .get_mut(&global_type)
554 .and_then(|any_state| any_state.downcast_mut::<G>())
555 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
556 .unwrap()
557 }
558
559 pub fn default_global<G: 'static + Default + Sync + Send>(&mut self) -> &mut G {
560 let global_type = TypeId::of::<G>();
561 self.push_effect(Effect::NotifyGlobalObservers { global_type });
562 self.globals_by_type
563 .entry(global_type)
564 .or_insert_with(|| Box::new(G::default()))
565 .downcast_mut::<G>()
566 .unwrap()
567 }
568
569 pub fn set_global<G: Any + Send + Sync>(&mut self, global: G) {
570 let global_type = TypeId::of::<G>();
571 self.push_effect(Effect::NotifyGlobalObservers { global_type });
572 self.globals_by_type.insert(global_type, Box::new(global));
573 }
574
575 pub fn update_global<G: 'static, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R {
576 let mut global = self.lease_global::<G>();
577 let result = f(&mut global, self);
578 self.end_global_lease(global);
579 result
580 }
581
582 pub fn observe_global<G: 'static>(
583 &mut self,
584 mut f: impl FnMut(&mut Self) + Send + Sync + 'static,
585 ) -> Subscription {
586 self.global_observers.insert(
587 TypeId::of::<G>(),
588 Box::new(move |cx| {
589 f(cx);
590 true
591 }),
592 )
593 }
594
595 pub(crate) fn lease_global<G: 'static>(&mut self) -> GlobalLease<G> {
596 GlobalLease::new(
597 self.globals_by_type
598 .remove(&TypeId::of::<G>())
599 .ok_or_else(|| anyhow!("no global registered of type {}", type_name::<G>()))
600 .unwrap(),
601 )
602 }
603
604 pub(crate) fn end_global_lease<G: 'static>(&mut self, lease: GlobalLease<G>) {
605 let global_type = TypeId::of::<G>();
606 self.push_effect(Effect::NotifyGlobalObservers { global_type });
607 self.globals_by_type.insert(global_type, lease.global);
608 }
609
610 pub(crate) fn push_text_style(&mut self, text_style: TextStyleRefinement) {
611 self.text_style_stack.push(text_style);
612 }
613
614 pub(crate) fn pop_text_style(&mut self) {
615 self.text_style_stack.pop();
616 }
617
618 pub fn bind_keys(&mut self, bindings: impl IntoIterator<Item = KeyBinding>) {
619 self.keymap.write().add_bindings(bindings);
620 self.pending_effects.push_back(Effect::Refresh);
621 }
622
623 pub fn on_action<A: Action>(
624 &mut self,
625 listener: impl Fn(&A, &mut Self) + Send + Sync + 'static,
626 ) {
627 self.global_action_listeners
628 .entry(TypeId::of::<A>())
629 .or_default()
630 .push(Box::new(move |action, phase, cx| {
631 if phase == DispatchPhase::Bubble {
632 let action = action.as_any().downcast_ref().unwrap();
633 listener(action, cx)
634 }
635 }));
636 }
637
638 pub fn register_action_type<A: Action>(&mut self) {
639 self.action_builders.insert(A::qualified_name(), A::build);
640 }
641
642 pub fn build_action(
643 &mut self,
644 name: &str,
645 params: Option<serde_json::Value>,
646 ) -> Result<Box<dyn Action>> {
647 let build = self
648 .action_builders
649 .get(name)
650 .ok_or_else(|| anyhow!("no action type registered for {}", name))?;
651 (build)(params)
652 }
653
654 pub fn stop_propagation(&mut self) {
655 self.propagate_event = false;
656 }
657}
658
659impl Context for AppContext {
660 type EntityContext<'a, 'w, T> = ModelContext<'a, T>;
661 type Result<T> = T;
662
663 fn entity<T: Any + Send + Sync>(
664 &mut self,
665 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
666 ) -> Handle<T> {
667 self.update(|cx| {
668 let slot = cx.entities.reserve();
669 let entity = build_entity(&mut ModelContext::mutable(cx, slot.downgrade()));
670 cx.entities.insert(slot, entity)
671 })
672 }
673
674 fn update_entity<T: 'static, R>(
675 &mut self,
676 handle: &Handle<T>,
677 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
678 ) -> R {
679 self.update(|cx| {
680 let mut entity = cx.entities.lease(handle);
681 let result = update(
682 &mut entity,
683 &mut ModelContext::mutable(cx, handle.downgrade()),
684 );
685 cx.entities.end_lease(entity);
686 result
687 })
688 }
689}
690
691impl<C> MainThread<C>
692where
693 C: Borrow<AppContext>,
694{
695 pub(crate) fn platform(&self) -> &dyn Platform {
696 self.0.borrow().platform.borrow_on_main_thread()
697 }
698
699 pub fn activate(&self, ignoring_other_apps: bool) {
700 self.platform().activate(ignoring_other_apps);
701 }
702
703 pub fn write_to_clipboard(&self, item: ClipboardItem) {
704 self.platform().write_to_clipboard(item)
705 }
706
707 pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
708 self.platform().read_from_clipboard()
709 }
710
711 pub fn write_credentials(&self, url: &str, username: &str, password: &[u8]) -> Result<()> {
712 self.platform().write_credentials(url, username, password)
713 }
714
715 pub fn read_credentials(&self, url: &str) -> Result<Option<(String, Vec<u8>)>> {
716 self.platform().read_credentials(url)
717 }
718
719 pub fn delete_credentials(&self, url: &str) -> Result<()> {
720 self.platform().delete_credentials(url)
721 }
722
723 pub fn open_url(&self, url: &str) {
724 self.platform().open_url(url);
725 }
726
727 pub fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf> {
728 self.platform().path_for_auxiliary_executable(name)
729 }
730}
731
732impl MainThread<AppContext> {
733 fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
734 self.0.update(|cx| {
735 update(unsafe {
736 std::mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx)
737 })
738 })
739 }
740
741 pub(crate) fn update_window<R>(
742 &mut self,
743 id: WindowId,
744 update: impl FnOnce(&mut MainThread<WindowContext>) -> R,
745 ) -> Result<R> {
746 self.0.update_window(id, |cx| {
747 update(unsafe {
748 std::mem::transmute::<&mut WindowContext, &mut MainThread<WindowContext>>(cx)
749 })
750 })
751 }
752
753 pub fn open_window<V: 'static>(
754 &mut self,
755 options: crate::WindowOptions,
756 build_root_view: impl FnOnce(&mut WindowContext) -> View<V> + Send + 'static,
757 ) -> WindowHandle<V> {
758 self.update(|cx| {
759 let id = cx.windows.insert(None);
760 let handle = WindowHandle::new(id);
761 let mut window = Window::new(handle.into(), options, cx);
762 let root_view = build_root_view(&mut WindowContext::mutable(cx, &mut window));
763 window.root_view.replace(root_view.into_any());
764 cx.windows.get_mut(id).unwrap().replace(window);
765 handle
766 })
767 }
768
769 pub fn update_global<G: 'static + Send + Sync, R>(
770 &mut self,
771 update: impl FnOnce(&mut G, &mut MainThread<AppContext>) -> R,
772 ) -> R {
773 self.0.update_global(|global, cx| {
774 let cx = unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) };
775 update(global, cx)
776 })
777 }
778}
779
780pub(crate) enum Effect {
781 Notify {
782 emitter: EntityId,
783 },
784 Emit {
785 emitter: EntityId,
786 event: Box<dyn Any + Send + Sync + 'static>,
787 },
788 FocusChanged {
789 window_id: WindowId,
790 focused: Option<FocusId>,
791 },
792 Refresh,
793 NotifyGlobalObservers {
794 global_type: TypeId,
795 },
796 Defer {
797 callback: Box<dyn FnOnce(&mut AppContext) + Send + Sync + 'static>,
798 },
799}
800
801pub(crate) struct GlobalLease<G: 'static> {
802 global: AnyBox,
803 global_type: PhantomData<G>,
804}
805
806impl<G: 'static> GlobalLease<G> {
807 fn new(global: AnyBox) -> Self {
808 GlobalLease {
809 global,
810 global_type: PhantomData,
811 }
812 }
813}
814
815impl<G: 'static> Deref for GlobalLease<G> {
816 type Target = G;
817
818 fn deref(&self) -> &Self::Target {
819 self.global.downcast_ref().unwrap()
820 }
821}
822
823impl<G: 'static> DerefMut for GlobalLease<G> {
824 fn deref_mut(&mut self) -> &mut Self::Target {
825 self.global.downcast_mut().unwrap()
826 }
827}
828
829pub(crate) struct AnyDrag {
830 pub drag_handle_view: Option<AnyView>,
831 pub cursor_offset: Point<Pixels>,
832 pub state: AnyBox,
833 pub state_type: TypeId,
834}
835
836#[cfg(test)]
837mod tests {
838 use super::AppContext;
839
840 #[test]
841 fn test_app_context_send_sync() {
842 // This will not compile if `AppContext` does not implement `Send`
843 fn assert_send<T: Send>() {}
844 assert_send::<AppContext>();
845 }
846}