app.rs

  1mod async_context;
  2mod entity_map;
  3mod model_context;
  4
  5pub use async_context::*;
  6pub use entity_map::*;
  7pub use model_context::*;
  8use refineable::Refineable;
  9use smallvec::SmallVec;
 10
 11use crate::{
 12    current_platform, image_cache::ImageCache, Action, AnyBox, AnyView, AppMetadata, AssetSource,
 13    Context, DispatchPhase, DisplayId, Executor, FocusEvent, FocusHandle, FocusId, KeyBinding,
 14    Keymap, LayoutId, MainThread, MainThreadOnly, Pixels, Platform, Point, SharedString,
 15    SubscriberSet, Subscription, SvgRenderer, Task, TextStyle, TextStyleRefinement, TextSystem,
 16    View, Window, WindowContext, WindowHandle, WindowId,
 17};
 18use anyhow::{anyhow, Result};
 19use collections::{HashMap, HashSet, VecDeque};
 20use futures::{future::BoxFuture, Future};
 21use parking_lot::{Mutex, RwLock};
 22use slotmap::SlotMap;
 23use std::{
 24    any::{type_name, Any, TypeId},
 25    mem,
 26    sync::{atomic::Ordering::SeqCst, Arc, Weak},
 27    time::Duration,
 28};
 29use util::http::{self, HttpClient};
 30
 31pub struct App(Arc<Mutex<AppContext>>);
 32
 33impl App {
 34    pub fn production(asset_source: Arc<dyn AssetSource>) -> Self {
 35        let http_client = http::client();
 36        Self::new(current_platform(), asset_source, http_client)
 37    }
 38
 39    #[cfg(any(test, feature = "test"))]
 40    pub fn test() -> Self {
 41        let platform = Arc::new(super::TestPlatform::new());
 42        let asset_source = Arc::new(());
 43        let http_client = util::http::FakeHttpClient::with_404_response();
 44        Self::new(platform, asset_source, http_client)
 45    }
 46
 47    fn new(
 48        platform: Arc<dyn Platform>,
 49        asset_source: Arc<dyn AssetSource>,
 50        http_client: Arc<dyn HttpClient>,
 51    ) -> Self {
 52        let executor = platform.executor();
 53        assert!(
 54            executor.is_main_thread(),
 55            "must construct App on main thread"
 56        );
 57
 58        let text_system = Arc::new(TextSystem::new(platform.text_system()));
 59        let mut entities = EntityMap::new();
 60        let unit_entity = entities.insert(entities.reserve(), ());
 61        let app_metadata = AppMetadata {
 62            os_name: platform.os_name(),
 63            os_version: platform.os_version().ok(),
 64            app_version: platform.app_version().ok(),
 65        };
 66        Self(Arc::new_cyclic(|this| {
 67            Mutex::new(AppContext {
 68                this: this.clone(),
 69                text_system,
 70                platform: MainThreadOnly::new(platform, executor.clone()),
 71                app_metadata,
 72                flushing_effects: false,
 73                pending_updates: 0,
 74                next_frame_callbacks: Default::default(),
 75                executor,
 76                svg_renderer: SvgRenderer::new(asset_source),
 77                image_cache: ImageCache::new(http_client),
 78                text_style_stack: Vec::new(),
 79                globals_by_type: HashMap::default(),
 80                unit_entity,
 81                entities,
 82                windows: SlotMap::with_key(),
 83                keymap: Arc::new(RwLock::new(Keymap::default())),
 84                global_action_listeners: HashMap::default(),
 85                action_builders: HashMap::default(),
 86                pending_effects: VecDeque::new(),
 87                pending_notifications: HashSet::default(),
 88                pending_global_notifications: HashSet::default(),
 89                observers: SubscriberSet::new(),
 90                event_listeners: SubscriberSet::new(),
 91                release_listeners: SubscriberSet::new(),
 92                global_observers: SubscriberSet::new(),
 93                quit_observers: SubscriberSet::new(),
 94                layout_id_buffer: Default::default(),
 95                propagate_event: true,
 96                active_drag: None,
 97            })
 98        }))
 99    }
100
101    pub fn run<F>(self, on_finish_launching: F)
102    where
103        F: 'static + FnOnce(&mut MainThread<AppContext>),
104    {
105        let this = self.0.clone();
106        let platform = self.0.lock().platform.clone();
107        platform.borrow_on_main_thread().run(Box::new(move || {
108            let cx = &mut *this.lock();
109            let cx = unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) };
110            on_finish_launching(cx);
111        }));
112    }
113
114    pub fn on_open_urls<F>(&self, mut callback: F) -> &Self
115    where
116        F: 'static + FnMut(Vec<String>, &mut AppContext),
117    {
118        let this = Arc::downgrade(&self.0);
119        self.0
120            .lock()
121            .platform
122            .borrow_on_main_thread()
123            .on_open_urls(Box::new(move |urls| {
124                if let Some(app) = this.upgrade() {
125                    callback(urls, &mut app.lock());
126                }
127            }));
128        self
129    }
130
131    pub fn on_reopen<F>(&self, mut callback: F) -> &Self
132    where
133        F: 'static + FnMut(&mut AppContext),
134    {
135        let this = Arc::downgrade(&self.0);
136        self.0
137            .lock()
138            .platform
139            .borrow_on_main_thread()
140            .on_reopen(Box::new(move || {
141                if let Some(app) = this.upgrade() {
142                    callback(&mut app.lock());
143                }
144            }));
145        self
146    }
147
148    pub fn metadata(&self) -> AppMetadata {
149        self.0.lock().app_metadata.clone()
150    }
151
152    pub fn executor(&self) -> Executor {
153        self.0.lock().executor.clone()
154    }
155
156    pub fn text_system(&self) -> Arc<TextSystem> {
157        self.0.lock().text_system.clone()
158    }
159}
160
161type ActionBuilder = fn(json: Option<serde_json::Value>) -> anyhow::Result<Box<dyn Action>>;
162type FrameCallback = Box<dyn FnOnce(&mut WindowContext) + Send>;
163type Handler = Box<dyn Fn(&mut AppContext) -> bool + Send + Sync + 'static>;
164type Listener = Box<dyn Fn(&dyn Any, &mut AppContext) -> bool + Send + Sync + 'static>;
165type QuitHandler = Box<dyn Fn(&mut AppContext) -> BoxFuture<'static, ()> + Send + Sync + 'static>;
166type ReleaseListener = Box<dyn Fn(&mut dyn Any, &mut AppContext) + Send + Sync + 'static>;
167
168pub struct AppContext {
169    this: Weak<Mutex<AppContext>>,
170    pub(crate) platform: MainThreadOnly<dyn Platform>,
171    app_metadata: AppMetadata,
172    text_system: Arc<TextSystem>,
173    flushing_effects: bool,
174    pending_updates: usize,
175    pub(crate) active_drag: Option<AnyDrag>,
176    pub(crate) next_frame_callbacks: HashMap<DisplayId, Vec<FrameCallback>>,
177    pub(crate) executor: Executor,
178    pub(crate) svg_renderer: SvgRenderer,
179    pub(crate) image_cache: ImageCache,
180    pub(crate) text_style_stack: Vec<TextStyleRefinement>,
181    pub(crate) globals_by_type: HashMap<TypeId, Box<dyn Any + Send + Sync>>,
182    pub(crate) unit_entity: Handle<()>,
183    pub(crate) entities: EntityMap,
184    pub(crate) windows: SlotMap<WindowId, Option<Window>>,
185    pub(crate) keymap: Arc<RwLock<Keymap>>,
186    pub(crate) global_action_listeners:
187        HashMap<TypeId, Vec<Box<dyn Fn(&dyn Action, DispatchPhase, &mut Self) + Send + Sync>>>,
188    action_builders: HashMap<SharedString, ActionBuilder>,
189    pending_effects: VecDeque<Effect>,
190    pub(crate) pending_notifications: HashSet<EntityId>,
191    pub(crate) pending_global_notifications: HashSet<TypeId>,
192    pub(crate) observers: SubscriberSet<EntityId, Handler>,
193    pub(crate) event_listeners: SubscriberSet<EntityId, Listener>,
194    pub(crate) release_listeners: SubscriberSet<EntityId, ReleaseListener>,
195    pub(crate) global_observers: SubscriberSet<TypeId, Handler>,
196    pub(crate) quit_observers: SubscriberSet<(), QuitHandler>,
197    pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
198    pub(crate) propagate_event: bool,
199}
200
201impl AppContext {
202    pub fn quit(&mut self) {
203        let mut futures = Vec::new();
204
205        self.quit_observers.clone().retain(&(), |observer| {
206            futures.push(observer(self));
207            true
208        });
209
210        self.windows.clear();
211        self.flush_effects();
212
213        let futures = futures::future::join_all(futures);
214        if self
215            .executor
216            .block_with_timeout(Duration::from_millis(100), futures)
217            .is_err()
218        {
219            log::error!("timed out waiting on app_will_quit");
220        }
221    }
222
223    pub fn app_metadata(&self) -> AppMetadata {
224        self.app_metadata.clone()
225    }
226
227    pub fn refresh(&mut self) {
228        self.pending_effects.push_back(Effect::Refresh);
229    }
230
231    pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
232        self.pending_updates += 1;
233        let result = update(self);
234        if !self.flushing_effects && self.pending_updates == 1 {
235            self.flushing_effects = true;
236            self.flush_effects();
237            self.flushing_effects = false;
238        }
239        self.pending_updates -= 1;
240        result
241    }
242
243    pub(crate) fn read_window<R>(
244        &mut self,
245        id: WindowId,
246        read: impl FnOnce(&WindowContext) -> R,
247    ) -> Result<R> {
248        let window = self
249            .windows
250            .get(id)
251            .ok_or_else(|| anyhow!("window not found"))?
252            .as_ref()
253            .unwrap();
254        Ok(read(&WindowContext::immutable(self, &window)))
255    }
256
257    pub(crate) fn update_window<R>(
258        &mut self,
259        id: WindowId,
260        update: impl FnOnce(&mut WindowContext) -> R,
261    ) -> Result<R> {
262        self.update(|cx| {
263            let mut window = cx
264                .windows
265                .get_mut(id)
266                .ok_or_else(|| anyhow!("window not found"))?
267                .take()
268                .unwrap();
269
270            let result = update(&mut WindowContext::mutable(cx, &mut window));
271
272            cx.windows
273                .get_mut(id)
274                .ok_or_else(|| anyhow!("window not found"))?
275                .replace(window);
276
277            Ok(result)
278        })
279    }
280
281    pub(crate) fn push_effect(&mut self, effect: Effect) {
282        match &effect {
283            Effect::Notify { emitter } => {
284                if !self.pending_notifications.insert(*emitter) {
285                    return;
286                }
287            }
288            Effect::NotifyGlobalObservers { global_type } => {
289                if !self.pending_global_notifications.insert(*global_type) {
290                    return;
291                }
292            }
293            _ => {}
294        };
295
296        self.pending_effects.push_back(effect);
297    }
298
299    fn flush_effects(&mut self) {
300        loop {
301            self.release_dropped_entities();
302            self.release_dropped_focus_handles();
303            if let Some(effect) = self.pending_effects.pop_front() {
304                match effect {
305                    Effect::Notify { emitter } => {
306                        self.apply_notify_effect(emitter);
307                    }
308                    Effect::Emit { emitter, event } => self.apply_emit_effect(emitter, event),
309                    Effect::FocusChanged { window_id, focused } => {
310                        self.apply_focus_changed_effect(window_id, focused);
311                    }
312                    Effect::Refresh => {
313                        self.apply_refresh_effect();
314                    }
315                    Effect::NotifyGlobalObservers { global_type } => {
316                        self.apply_notify_global_observers_effect(global_type);
317                    }
318                }
319            } else {
320                break;
321            }
322        }
323
324        let dirty_window_ids = self
325            .windows
326            .iter()
327            .filter_map(|(window_id, window)| {
328                let window = window.as_ref().unwrap();
329                if window.dirty {
330                    Some(window_id)
331                } else {
332                    None
333                }
334            })
335            .collect::<SmallVec<[_; 8]>>();
336
337        for dirty_window_id in dirty_window_ids {
338            self.update_window(dirty_window_id, |cx| cx.draw()).unwrap();
339        }
340    }
341
342    fn release_dropped_entities(&mut self) {
343        loop {
344            let dropped = self.entities.take_dropped();
345            if dropped.is_empty() {
346                break;
347            }
348
349            for (entity_id, mut entity) in dropped {
350                self.observers.remove(&entity_id);
351                self.event_listeners.remove(&entity_id);
352                for release_callback in self.release_listeners.remove(&entity_id) {
353                    release_callback(&mut entity, self);
354                }
355            }
356        }
357    }
358
359    fn release_dropped_focus_handles(&mut self) {
360        let window_ids = self.windows.keys().collect::<SmallVec<[_; 8]>>();
361        for window_id in window_ids {
362            self.update_window(window_id, |cx| {
363                let mut blur_window = false;
364                let focus = cx.window.focus;
365                cx.window.focus_handles.write().retain(|handle_id, count| {
366                    if count.load(SeqCst) == 0 {
367                        if focus == Some(handle_id) {
368                            blur_window = true;
369                        }
370                        false
371                    } else {
372                        true
373                    }
374                });
375
376                if blur_window {
377                    cx.blur();
378                }
379            })
380            .unwrap();
381        }
382    }
383
384    fn apply_notify_effect(&mut self, emitter: EntityId) {
385        self.pending_notifications.remove(&emitter);
386        self.observers
387            .clone()
388            .retain(&emitter, |handler| handler(self));
389    }
390
391    fn apply_emit_effect(&mut self, emitter: EntityId, event: Box<dyn Any>) {
392        self.event_listeners
393            .clone()
394            .retain(&emitter, |handler| handler(&event, self));
395    }
396
397    fn apply_focus_changed_effect(&mut self, window_id: WindowId, focused: Option<FocusId>) {
398        self.update_window(window_id, |cx| {
399            if cx.window.focus == focused {
400                let mut listeners = mem::take(&mut cx.window.focus_listeners);
401                let focused =
402                    focused.map(|id| FocusHandle::for_id(id, &cx.window.focus_handles).unwrap());
403                let blurred = cx
404                    .window
405                    .last_blur
406                    .take()
407                    .unwrap()
408                    .and_then(|id| FocusHandle::for_id(id, &cx.window.focus_handles));
409                if focused.is_some() || blurred.is_some() {
410                    let event = FocusEvent { focused, blurred };
411                    for listener in &listeners {
412                        listener(&event, cx);
413                    }
414                }
415
416                listeners.extend(cx.window.focus_listeners.drain(..));
417                cx.window.focus_listeners = listeners;
418            }
419        })
420        .ok();
421    }
422
423    fn apply_refresh_effect(&mut self) {
424        for window in self.windows.values_mut() {
425            if let Some(window) = window.as_mut() {
426                window.dirty = true;
427            }
428        }
429    }
430
431    fn apply_notify_global_observers_effect(&mut self, type_id: TypeId) {
432        self.pending_global_notifications.remove(&type_id);
433        self.global_observers
434            .clone()
435            .retain(&type_id, |observer| observer(self));
436    }
437
438    pub fn to_async(&self) -> AsyncAppContext {
439        AsyncAppContext {
440            app: unsafe { mem::transmute(self.this.clone()) },
441            executor: self.executor.clone(),
442        }
443    }
444
445    pub fn executor(&self) -> &Executor {
446        &self.executor
447    }
448
449    pub fn run_on_main<R>(
450        &mut self,
451        f: impl FnOnce(&mut MainThread<AppContext>) -> R + Send + 'static,
452    ) -> Task<R>
453    where
454        R: Send + 'static,
455    {
456        if self.executor.is_main_thread() {
457            Task::ready(f(unsafe {
458                mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(self)
459            }))
460        } else {
461            let this = self.this.upgrade().unwrap();
462            self.executor.run_on_main(move || {
463                let cx = &mut *this.lock();
464                cx.update(|cx| f(unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(cx) }))
465            })
466        }
467    }
468
469    pub fn spawn_on_main<F, R>(
470        &self,
471        f: impl FnOnce(&mut MainThread<AppContext>) -> F + Send + 'static,
472    ) -> Task<R>
473    where
474        F: Future<Output = R> + 'static,
475        R: Send + 'static,
476    {
477        let this = self.this.upgrade().unwrap();
478        self.executor.spawn_on_main(move || {
479            let cx = &mut *this.lock();
480            cx.update(|cx| {
481                f(unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) })
482            })
483        })
484    }
485
486    pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncAppContext) -> Fut + Send + 'static) -> Task<R>
487    where
488        Fut: Future<Output = R> + Send + 'static,
489        R: Send + 'static,
490    {
491        let cx = self.to_async();
492        self.executor.spawn(async move {
493            let future = f(cx);
494            future.await
495        })
496    }
497
498    pub fn text_system(&self) -> &Arc<TextSystem> {
499        &self.text_system
500    }
501
502    pub fn text_style(&self) -> TextStyle {
503        let mut style = TextStyle::default();
504        for refinement in &self.text_style_stack {
505            style.refine(refinement);
506        }
507        style
508    }
509
510    pub fn has_global<G: 'static>(&self) -> bool {
511        self.globals_by_type.contains_key(&TypeId::of::<G>())
512    }
513
514    pub fn global<G: 'static>(&self) -> &G {
515        self.globals_by_type
516            .get(&TypeId::of::<G>())
517            .map(|any_state| any_state.downcast_ref::<G>().unwrap())
518            .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
519            .unwrap()
520    }
521
522    pub fn try_global<G: 'static>(&self) -> Option<&G> {
523        self.globals_by_type
524            .get(&TypeId::of::<G>())
525            .map(|any_state| any_state.downcast_ref::<G>().unwrap())
526    }
527
528    pub fn global_mut<G: 'static>(&mut self) -> &mut G {
529        let global_type = TypeId::of::<G>();
530        self.push_effect(Effect::NotifyGlobalObservers { global_type });
531        self.globals_by_type
532            .get_mut(&global_type)
533            .and_then(|any_state| any_state.downcast_mut::<G>())
534            .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
535            .unwrap()
536    }
537
538    pub fn default_global_mut<G: 'static + Default + Sync + Send>(&mut self) -> &mut G {
539        let global_type = TypeId::of::<G>();
540        self.push_effect(Effect::NotifyGlobalObservers { global_type });
541        self.globals_by_type
542            .entry(global_type)
543            .or_insert_with(|| Box::new(G::default()))
544            .downcast_mut::<G>()
545            .unwrap()
546    }
547
548    pub fn set_global<T: Send + Sync + 'static>(&mut self, global: T) {
549        let global_type = TypeId::of::<T>();
550        self.push_effect(Effect::NotifyGlobalObservers { global_type });
551        self.globals_by_type.insert(global_type, Box::new(global));
552    }
553
554    pub fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
555    where
556        G: 'static + Send + Sync,
557    {
558        let mut global = self.lease_global::<G>();
559        let result = f(global.as_mut(), self);
560        self.restore_global(global);
561        result
562    }
563
564    pub fn observe_global<G: 'static>(
565        &mut self,
566        f: impl Fn(&mut Self) + Send + Sync + 'static,
567    ) -> Subscription {
568        self.global_observers.insert(
569            TypeId::of::<G>(),
570            Box::new(move |cx| {
571                f(cx);
572                true
573            }),
574        )
575    }
576
577    pub(crate) fn lease_global<G: 'static + Send + Sync>(&mut self) -> Box<G> {
578        self.globals_by_type
579            .remove(&TypeId::of::<G>())
580            .ok_or_else(|| anyhow!("no global registered of type {}", type_name::<G>()))
581            .unwrap()
582            .downcast()
583            .unwrap()
584    }
585
586    pub(crate) fn restore_global<G: 'static + Send + Sync>(&mut self, global: Box<G>) {
587        let global_type = TypeId::of::<G>();
588        self.push_effect(Effect::NotifyGlobalObservers { global_type });
589        self.globals_by_type.insert(global_type, global);
590    }
591
592    pub(crate) fn push_text_style(&mut self, text_style: TextStyleRefinement) {
593        self.text_style_stack.push(text_style);
594    }
595
596    pub(crate) fn pop_text_style(&mut self) {
597        self.text_style_stack.pop();
598    }
599
600    pub fn bind_keys(&mut self, bindings: impl IntoIterator<Item = KeyBinding>) {
601        self.keymap.write().add_bindings(bindings);
602        self.pending_effects.push_back(Effect::Refresh);
603    }
604
605    pub fn on_action<A: Action>(
606        &mut self,
607        listener: impl Fn(&A, &mut Self) + Send + Sync + 'static,
608    ) {
609        self.global_action_listeners
610            .entry(TypeId::of::<A>())
611            .or_default()
612            .push(Box::new(move |action, phase, cx| {
613                if phase == DispatchPhase::Bubble {
614                    let action = action.as_any().downcast_ref().unwrap();
615                    listener(action, cx)
616                }
617            }));
618    }
619
620    pub fn register_action_type<A: Action>(&mut self) {
621        self.action_builders.insert(A::qualified_name(), A::build);
622    }
623
624    pub fn build_action(
625        &mut self,
626        name: &str,
627        params: Option<serde_json::Value>,
628    ) -> Result<Box<dyn Action>> {
629        let build = self
630            .action_builders
631            .get(name)
632            .ok_or_else(|| anyhow!("no action type registered for {}", name))?;
633        (build)(params)
634    }
635
636    pub fn stop_propagation(&mut self) {
637        self.propagate_event = false;
638    }
639}
640
641impl Context for AppContext {
642    type EntityContext<'a, 'w, T: Send + Sync + 'static> = ModelContext<'a, T>;
643    type Result<T> = T;
644
645    fn entity<T: Send + Sync + 'static>(
646        &mut self,
647        build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
648    ) -> Handle<T> {
649        self.update(|cx| {
650            let slot = cx.entities.reserve();
651            let entity = build_entity(&mut ModelContext::mutable(cx, slot.entity_id));
652            cx.entities.insert(slot, entity)
653        })
654    }
655
656    fn update_entity<T: Send + Sync + 'static, R>(
657        &mut self,
658        handle: &Handle<T>,
659        update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
660    ) -> R {
661        self.update(|cx| {
662            let mut entity = cx.entities.lease(handle);
663            let result = update(
664                &mut entity,
665                &mut ModelContext::mutable(cx, handle.entity_id),
666            );
667            cx.entities.end_lease(entity);
668            result
669        })
670    }
671}
672
673impl MainThread<AppContext> {
674    fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
675        self.0.update(|cx| {
676            update(unsafe {
677                std::mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx)
678            })
679        })
680    }
681
682    pub(crate) fn update_window<R>(
683        &mut self,
684        id: WindowId,
685        update: impl FnOnce(&mut MainThread<WindowContext>) -> R,
686    ) -> Result<R> {
687        self.0.update_window(id, |cx| {
688            update(unsafe {
689                std::mem::transmute::<&mut WindowContext, &mut MainThread<WindowContext>>(cx)
690            })
691        })
692    }
693
694    pub(crate) fn platform(&self) -> &dyn Platform {
695        self.platform.borrow_on_main_thread()
696    }
697
698    pub fn activate(&self, ignoring_other_apps: bool) {
699        self.platform().activate(ignoring_other_apps);
700    }
701
702    pub fn write_credentials(&self, url: &str, username: &str, password: &[u8]) -> Result<()> {
703        self.platform().write_credentials(url, username, password)
704    }
705
706    pub fn read_credentials(&self, url: &str) -> Result<Option<(String, Vec<u8>)>> {
707        self.platform().read_credentials(url)
708    }
709
710    pub fn delete_credentials(&self, url: &str) -> Result<()> {
711        self.platform().delete_credentials(url)
712    }
713
714    pub fn open_url(&self, url: &str) {
715        self.platform().open_url(url);
716    }
717
718    pub fn open_window<S: 'static + Send + Sync>(
719        &mut self,
720        options: crate::WindowOptions,
721        build_root_view: impl FnOnce(&mut WindowContext) -> View<S> + Send + 'static,
722    ) -> WindowHandle<S> {
723        self.update(|cx| {
724            let id = cx.windows.insert(None);
725            let handle = WindowHandle::new(id);
726            let mut window = Window::new(handle.into(), options, cx);
727            let root_view = build_root_view(&mut WindowContext::mutable(cx, &mut window));
728            window.root_view.replace(root_view.into_any());
729            cx.windows.get_mut(id).unwrap().replace(window);
730            handle
731        })
732    }
733
734    pub fn update_global<G: 'static + Send + Sync, R>(
735        &mut self,
736        update: impl FnOnce(&mut G, &mut MainThread<AppContext>) -> R,
737    ) -> R {
738        self.0.update_global(|global, cx| {
739            let cx = unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) };
740            update(global, cx)
741        })
742    }
743}
744
745pub(crate) enum Effect {
746    Notify {
747        emitter: EntityId,
748    },
749    Emit {
750        emitter: EntityId,
751        event: Box<dyn Any + Send + Sync + 'static>,
752    },
753    FocusChanged {
754        window_id: WindowId,
755        focused: Option<FocusId>,
756    },
757    Refresh,
758    NotifyGlobalObservers {
759        global_type: TypeId,
760    },
761}
762
763pub(crate) struct AnyDrag {
764    pub drag_handle_view: AnyView,
765    pub cursor_offset: Point<Pixels>,
766    pub state: AnyBox,
767    pub state_type: TypeId,
768}
769
770#[cfg(test)]
771mod tests {
772    use super::AppContext;
773
774    #[test]
775    fn test_app_context_send_sync() {
776        // This will not compile if `AppContext` does not implement `Send`
777        fn assert_send<T: Send>() {}
778        assert_send::<AppContext>();
779    }
780}