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, AssetSource, Context, DisplayId, Executor,
13 FocusEvent, FocusHandle, FocusId, KeyBinding, Keymap, LayoutId, MainThread, MainThreadOnly,
14 Platform, SubscriberSet, SvgRenderer, Task, TextStyle, TextStyleRefinement, TextSystem, View,
15 Window, WindowContext, WindowHandle, WindowId,
16};
17use anyhow::{anyhow, Result};
18use collections::{HashMap, HashSet, VecDeque};
19use futures::Future;
20use parking_lot::{Mutex, RwLock};
21use slotmap::SlotMap;
22use std::{
23 any::{type_name, Any, TypeId},
24 mem,
25 sync::{atomic::Ordering::SeqCst, Arc, Weak},
26};
27use util::http::{self, HttpClient};
28
29#[derive(Clone)]
30pub struct App(Arc<Mutex<AppContext>>);
31
32impl App {
33 pub fn production(asset_source: Arc<dyn AssetSource>) -> Self {
34 let http_client = http::client();
35 Self::new(current_platform(), asset_source, http_client)
36 }
37
38 #[cfg(any(test, feature = "test"))]
39 pub fn test() -> Self {
40 let platform = Arc::new(super::TestPlatform::new());
41 let asset_source = Arc::new(());
42 let http_client = util::http::FakeHttpClient::with_404_response();
43 Self::new(platform, asset_source, http_client)
44 }
45
46 fn new(
47 platform: Arc<dyn Platform>,
48 asset_source: Arc<dyn AssetSource>,
49 http_client: Arc<dyn HttpClient>,
50 ) -> Self {
51 let executor = platform.executor();
52 let entities = EntityMap::new();
53 let unit_entity = entities.insert(entities.reserve(), ());
54 Self(Arc::new_cyclic(|this| {
55 Mutex::new(AppContext {
56 this: this.clone(),
57 text_system: Arc::new(TextSystem::new(platform.text_system())),
58 pending_updates: 0,
59 flushing_effects: false,
60 next_frame_callbacks: Default::default(),
61 platform: MainThreadOnly::new(platform, executor.clone()),
62 executor,
63 svg_renderer: SvgRenderer::new(asset_source),
64 image_cache: ImageCache::new(http_client),
65 text_style_stack: Vec::new(),
66 global_stacks_by_type: HashMap::default(),
67 unit_entity,
68 entities,
69 windows: SlotMap::with_key(),
70 keymap: Arc::new(RwLock::new(Keymap::default())),
71 pending_notifications: Default::default(),
72 pending_effects: Default::default(),
73 observers: SubscriberSet::new(),
74 event_handlers: SubscriberSet::new(),
75 release_handlers: SubscriberSet::new(),
76 layout_id_buffer: Default::default(),
77 })
78 }))
79 }
80
81 pub fn run<F>(self, on_finish_launching: F)
82 where
83 F: 'static + FnOnce(&mut MainThread<AppContext>),
84 {
85 let this = self.clone();
86 let platform = self.0.lock().platform.clone();
87 platform.borrow_on_main_thread().run(Box::new(move || {
88 let cx = &mut *this.0.lock();
89 let cx = unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) };
90 on_finish_launching(cx);
91 }));
92 }
93}
94
95type Handler = Box<dyn Fn(&mut AppContext) -> bool + Send + Sync + 'static>;
96type EventHandler = Box<dyn Fn(&dyn Any, &mut AppContext) -> bool + Send + Sync + 'static>;
97type ReleaseHandler = Box<dyn Fn(&mut dyn Any, &mut AppContext) + Send + Sync + 'static>;
98type FrameCallback = Box<dyn FnOnce(&mut WindowContext) + Send>;
99
100pub struct AppContext {
101 this: Weak<Mutex<AppContext>>,
102 pub(crate) platform: MainThreadOnly<dyn Platform>,
103 text_system: Arc<TextSystem>,
104 flushing_effects: bool,
105 pending_updates: usize,
106 pub(crate) next_frame_callbacks: HashMap<DisplayId, Vec<FrameCallback>>,
107 pub(crate) executor: Executor,
108 pub(crate) svg_renderer: SvgRenderer,
109 pub(crate) image_cache: ImageCache,
110 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
111 pub(crate) global_stacks_by_type: HashMap<TypeId, Vec<Box<dyn Any + Send + Sync>>>,
112 pub(crate) unit_entity: Handle<()>,
113 pub(crate) entities: EntityMap,
114 pub(crate) windows: SlotMap<WindowId, Option<Window>>,
115 pub(crate) keymap: Arc<RwLock<Keymap>>,
116 pub(crate) pending_notifications: HashSet<EntityId>,
117 pending_effects: VecDeque<Effect>,
118 pub(crate) observers: SubscriberSet<EntityId, Handler>,
119 pub(crate) event_handlers: SubscriberSet<EntityId, EventHandler>,
120 pub(crate) release_handlers: SubscriberSet<EntityId, ReleaseHandler>,
121 pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
122}
123
124impl AppContext {
125 pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
126 self.pending_updates += 1;
127 let result = update(self);
128 if !self.flushing_effects && self.pending_updates == 1 {
129 self.flushing_effects = true;
130 self.flush_effects();
131 self.flushing_effects = false;
132 }
133 self.pending_updates -= 1;
134 result
135 }
136
137 pub(crate) fn update_window<R>(
138 &mut self,
139 id: WindowId,
140 update: impl FnOnce(&mut WindowContext) -> R,
141 ) -> Result<R> {
142 self.update(|cx| {
143 let mut window = cx
144 .windows
145 .get_mut(id)
146 .ok_or_else(|| anyhow!("window not found"))?
147 .take()
148 .unwrap();
149
150 let result = update(&mut WindowContext::mutable(cx, &mut window));
151
152 cx.windows
153 .get_mut(id)
154 .ok_or_else(|| anyhow!("window not found"))?
155 .replace(window);
156
157 Ok(result)
158 })
159 }
160
161 pub(crate) fn push_effect(&mut self, effect: Effect) {
162 match &effect {
163 Effect::Notify { emitter } => {
164 if self.pending_notifications.insert(*emitter) {
165 self.pending_effects.push_back(effect);
166 }
167 }
168 Effect::Emit { .. } => self.pending_effects.push_back(effect),
169 Effect::FocusChanged { .. } => self.pending_effects.push_back(effect),
170 Effect::Refresh => self.pending_effects.push_back(effect),
171 }
172 }
173
174 fn flush_effects(&mut self) {
175 loop {
176 self.release_dropped_entities();
177 self.release_dropped_focus_handles();
178 if let Some(effect) = self.pending_effects.pop_front() {
179 match effect {
180 Effect::Notify { emitter } => self.apply_notify_effect(emitter),
181 Effect::Emit { emitter, event } => self.apply_emit_effect(emitter, event),
182 Effect::FocusChanged { window_id, focused } => {
183 self.apply_focus_changed(window_id, focused)
184 }
185 Effect::Refresh => {
186 self.apply_refresh();
187 }
188 }
189 } else {
190 break;
191 }
192 }
193
194 let dirty_window_ids = self
195 .windows
196 .iter()
197 .filter_map(|(window_id, window)| {
198 let window = window.as_ref().unwrap();
199 if window.dirty {
200 Some(window_id)
201 } else {
202 None
203 }
204 })
205 .collect::<SmallVec<[_; 8]>>();
206
207 for dirty_window_id in dirty_window_ids {
208 self.update_window(dirty_window_id, |cx| cx.draw()).unwrap();
209 }
210 }
211
212 fn release_dropped_entities(&mut self) {
213 loop {
214 let dropped = self.entities.take_dropped();
215 if dropped.is_empty() {
216 break;
217 }
218
219 for (entity_id, mut entity) in dropped {
220 self.observers.remove(&entity_id);
221 self.event_handlers.remove(&entity_id);
222 for release_callback in self.release_handlers.remove(&entity_id) {
223 release_callback(&mut entity, self);
224 }
225 }
226 }
227 }
228
229 fn release_dropped_focus_handles(&mut self) {
230 let window_ids = self.windows.keys().collect::<SmallVec<[_; 8]>>();
231 for window_id in window_ids {
232 self.update_window(window_id, |cx| {
233 let mut blur_window = false;
234 let focus = cx.window.focus;
235 cx.window.focus_handles.write().retain(|handle_id, count| {
236 if count.load(SeqCst) == 0 {
237 if focus == Some(handle_id) {
238 blur_window = true;
239 }
240 false
241 } else {
242 true
243 }
244 });
245
246 if blur_window {
247 cx.blur();
248 }
249 })
250 .unwrap();
251 }
252 }
253
254 fn apply_notify_effect(&mut self, emitter: EntityId) {
255 self.pending_notifications.remove(&emitter);
256 self.observers
257 .clone()
258 .retain(&emitter, |handler| handler(self));
259 }
260
261 fn apply_emit_effect(&mut self, emitter: EntityId, event: Box<dyn Any>) {
262 self.event_handlers
263 .clone()
264 .retain(&emitter, |handler| handler(&event, self));
265 }
266
267 fn apply_focus_changed(&mut self, window_id: WindowId, focused: Option<FocusId>) {
268 self.update_window(window_id, |cx| {
269 if cx.window.focus == focused {
270 let mut listeners = mem::take(&mut cx.window.focus_listeners);
271 let focused =
272 focused.map(|id| FocusHandle::for_id(id, &cx.window.focus_handles).unwrap());
273 let blurred = cx
274 .window
275 .last_blur
276 .take()
277 .unwrap()
278 .and_then(|id| FocusHandle::for_id(id, &cx.window.focus_handles));
279 if focused.is_some() || blurred.is_some() {
280 let event = FocusEvent { focused, blurred };
281 for listener in &listeners {
282 listener(&event, cx);
283 }
284 }
285
286 listeners.extend(cx.window.focus_listeners.drain(..));
287 cx.window.focus_listeners = listeners;
288 }
289 })
290 .ok();
291 }
292
293 pub fn apply_refresh(&mut self) {
294 for window in self.windows.values_mut() {
295 if let Some(window) = window.as_mut() {
296 window.dirty = true;
297 }
298 }
299 }
300
301 pub fn to_async(&self) -> AsyncAppContext {
302 AsyncAppContext(unsafe { mem::transmute(self.this.clone()) })
303 }
304
305 pub fn executor(&self) -> &Executor {
306 &self.executor
307 }
308
309 pub fn run_on_main<R>(
310 &mut self,
311 f: impl FnOnce(&mut MainThread<AppContext>) -> R + Send + 'static,
312 ) -> Task<R>
313 where
314 R: Send + 'static,
315 {
316 if self.executor.is_main_thread() {
317 Task::ready(f(unsafe {
318 mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(self)
319 }))
320 } else {
321 let this = self.this.upgrade().unwrap();
322 self.executor.run_on_main(move || {
323 let cx = &mut *this.lock();
324 cx.update(|cx| f(unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(cx) }))
325 })
326 }
327 }
328
329 pub fn spawn_on_main<F, R>(
330 &self,
331 f: impl FnOnce(&mut MainThread<AppContext>) -> F + Send + 'static,
332 ) -> Task<R>
333 where
334 F: Future<Output = R> + 'static,
335 R: Send + 'static,
336 {
337 let this = self.this.upgrade().unwrap();
338 self.executor.spawn_on_main(move || {
339 let cx = &mut *this.lock();
340 cx.update(|cx| {
341 f(unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) })
342 })
343 })
344 }
345
346 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncAppContext) -> Fut + Send + 'static) -> Task<R>
347 where
348 Fut: Future<Output = R> + Send + 'static,
349 R: Send + 'static,
350 {
351 let cx = self.to_async();
352 self.executor.spawn(async move {
353 let future = f(cx);
354 future.await
355 })
356 }
357
358 pub fn text_system(&self) -> &Arc<TextSystem> {
359 &self.text_system
360 }
361
362 pub fn text_style(&self) -> TextStyle {
363 let mut style = TextStyle::default();
364 for refinement in &self.text_style_stack {
365 style.refine(refinement);
366 }
367 style
368 }
369
370 pub fn global<G: 'static>(&self) -> &G {
371 self.global_stacks_by_type
372 .get(&TypeId::of::<G>())
373 .and_then(|stack| stack.last())
374 .and_then(|any_state| any_state.downcast_ref::<G>())
375 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
376 .unwrap()
377 }
378
379 pub fn global_mut<G: 'static>(&mut self) -> &mut G {
380 self.global_stacks_by_type
381 .get_mut(&TypeId::of::<G>())
382 .and_then(|stack| stack.last_mut())
383 .and_then(|any_state| any_state.downcast_mut::<G>())
384 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<G>()))
385 .unwrap()
386 }
387
388 pub fn default_global<G: 'static + Default + Sync + Send>(&mut self) -> &mut G {
389 let stack = self
390 .global_stacks_by_type
391 .entry(TypeId::of::<G>())
392 .or_default();
393 if stack.is_empty() {
394 stack.push(Box::new(G::default()));
395 }
396 stack.last_mut().unwrap().downcast_mut::<G>().unwrap()
397 }
398
399 pub(crate) fn push_global<T: Send + Sync + 'static>(&mut self, state: T) {
400 self.global_stacks_by_type
401 .entry(TypeId::of::<T>())
402 .or_default()
403 .push(Box::new(state));
404 }
405
406 pub(crate) fn pop_global<T: 'static>(&mut self) {
407 self.global_stacks_by_type
408 .get_mut(&TypeId::of::<T>())
409 .and_then(|stack| stack.pop())
410 .expect("state stack underflow");
411 }
412
413 pub(crate) fn push_text_style(&mut self, text_style: TextStyleRefinement) {
414 self.text_style_stack.push(text_style);
415 }
416
417 pub(crate) fn pop_text_style(&mut self) {
418 self.text_style_stack.pop();
419 }
420
421 pub fn bind_keys(&mut self, bindings: impl IntoIterator<Item = KeyBinding>) {
422 self.keymap.write().add_bindings(bindings);
423 self.push_effect(Effect::Refresh);
424 }
425}
426
427impl Context for AppContext {
428 type EntityContext<'a, 'w, T: Send + Sync + 'static> = ModelContext<'a, T>;
429 type Result<T> = T;
430
431 fn entity<T: Send + Sync + 'static>(
432 &mut self,
433 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
434 ) -> Handle<T> {
435 self.update(|cx| {
436 let slot = cx.entities.reserve();
437 let entity = build_entity(&mut ModelContext::mutable(cx, slot.id));
438 cx.entities.insert(slot, entity)
439 })
440 }
441
442 fn update_entity<T: Send + Sync + 'static, R>(
443 &mut self,
444 handle: &Handle<T>,
445 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
446 ) -> R {
447 self.update(|cx| {
448 let mut entity = cx.entities.lease(handle);
449 let result = update(&mut entity, &mut ModelContext::mutable(cx, handle.id));
450 cx.entities.end_lease(entity);
451 result
452 })
453 }
454}
455
456impl MainThread<AppContext> {
457 fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
458 self.0.update(|cx| {
459 update(unsafe {
460 std::mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx)
461 })
462 })
463 }
464
465 pub(crate) fn update_window<R>(
466 &mut self,
467 id: WindowId,
468 update: impl FnOnce(&mut MainThread<WindowContext>) -> R,
469 ) -> Result<R> {
470 self.0.update_window(id, |cx| {
471 update(unsafe {
472 std::mem::transmute::<&mut WindowContext, &mut MainThread<WindowContext>>(cx)
473 })
474 })
475 }
476
477 pub(crate) fn platform(&self) -> &dyn Platform {
478 self.platform.borrow_on_main_thread()
479 }
480
481 pub fn activate(&mut self, ignoring_other_apps: bool) {
482 self.platform().activate(ignoring_other_apps);
483 }
484
485 pub fn open_window<S: 'static + Send + Sync>(
486 &mut self,
487 options: crate::WindowOptions,
488 build_root_view: impl FnOnce(&mut WindowContext) -> View<S> + Send + 'static,
489 ) -> WindowHandle<S> {
490 self.update(|cx| {
491 let id = cx.windows.insert(None);
492 let handle = WindowHandle::new(id);
493 let mut window = Window::new(handle.into(), options, cx);
494 let root_view = build_root_view(&mut WindowContext::mutable(cx, &mut window));
495 window.root_view.replace(root_view.into_any());
496 cx.windows.get_mut(id).unwrap().replace(window);
497 handle
498 })
499 }
500}
501
502pub(crate) enum Effect {
503 Notify {
504 emitter: EntityId,
505 },
506 Emit {
507 emitter: EntityId,
508 event: Box<dyn Any + Send + Sync + 'static>,
509 },
510 FocusChanged {
511 window_id: WindowId,
512 focused: Option<FocusId>,
513 },
514 Refresh,
515}
516
517#[cfg(test)]
518mod tests {
519 use super::AppContext;
520
521 #[test]
522 fn test_app_context_send_sync() {
523 // This will not compile if `AppContext` does not implement `Send`
524 fn assert_send<T: Send>() {}
525 assert_send::<AppContext>();
526 }
527}