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;
9
10use crate::{
11 current_platform, image_cache::ImageCache, AssetSource, Context, DisplayLinker, Executor,
12 LayoutId, MainThread, MainThreadOnly, Platform, RootView, SvgRenderer, Task, TextStyle,
13 TextStyleRefinement, TextSystem, Window, WindowContext, WindowHandle, WindowId,
14};
15use anyhow::{anyhow, Result};
16use collections::{HashMap, VecDeque};
17use futures::Future;
18use parking_lot::Mutex;
19use slotmap::SlotMap;
20use smallvec::SmallVec;
21use std::{
22 any::{type_name, Any, TypeId},
23 mem,
24 sync::{Arc, Weak},
25};
26use util::{
27 http::{self, HttpClient},
28 ResultExt,
29};
30
31#[derive(Clone)]
32pub struct App(Arc<Mutex<AppContext>>);
33
34impl App {
35 pub fn production(asset_source: Arc<dyn AssetSource>) -> Self {
36 let http_client = http::client();
37 Self::new(current_platform(), asset_source, http_client)
38 }
39
40 #[cfg(any(test, feature = "test"))]
41 pub fn test() -> Self {
42 let platform = Arc::new(super::TestPlatform::new());
43 let asset_source = Arc::new(());
44 let http_client = util::http::FakeHttpClient::with_404_response();
45 Self::new(platform, asset_source, http_client)
46 }
47
48 fn new(
49 platform: Arc<dyn Platform>,
50 asset_source: Arc<dyn AssetSource>,
51 http_client: Arc<dyn HttpClient>,
52 ) -> Self {
53 let executor = platform.executor();
54 let entities = EntityMap::new();
55 let unit_entity = entities.insert(entities.reserve(), ());
56 Self(Arc::new_cyclic(|this| {
57 Mutex::new(AppContext {
58 this: this.clone(),
59 display_linker: Arc::new(DisplayLinker::new(platform.display_linker())),
60 text_system: Arc::new(TextSystem::new(platform.text_system())),
61 platform: MainThreadOnly::new(platform, executor.clone()),
62 executor,
63 svg_renderer: SvgRenderer::new(asset_source),
64 image_cache: ImageCache::new(http_client),
65 pending_updates: 0,
66 text_style_stack: Vec::new(),
67 state_stacks_by_type: HashMap::default(),
68 unit_entity,
69 entities,
70 windows: SlotMap::with_key(),
71 pending_effects: Default::default(),
72 observers: Default::default(),
73 layout_id_buffer: Default::default(),
74 })
75 }))
76 }
77
78 pub fn run<F>(self, on_finish_launching: F)
79 where
80 F: 'static + FnOnce(&mut MainThread<AppContext>),
81 {
82 let this = self.clone();
83 let platform = self.0.lock().platform.clone();
84 platform.borrow_on_main_thread().run(Box::new(move || {
85 let cx = &mut *this.0.lock();
86 let cx = unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) };
87 on_finish_launching(cx);
88 }));
89 }
90}
91
92type Handlers = SmallVec<[Arc<dyn Fn(&mut AppContext) -> bool + Send + Sync + 'static>; 2]>;
93
94pub struct AppContext {
95 this: Weak<Mutex<AppContext>>,
96 platform: MainThreadOnly<dyn Platform>,
97 text_system: Arc<TextSystem>,
98 pending_updates: usize,
99 pub(crate) executor: Executor,
100 pub(crate) display_linker: Arc<DisplayLinker>,
101 pub(crate) svg_renderer: SvgRenderer,
102 pub(crate) image_cache: ImageCache,
103 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
104 pub(crate) state_stacks_by_type: HashMap<TypeId, Vec<Box<dyn Any + Send + Sync>>>,
105 pub(crate) unit_entity: Handle<()>,
106 pub(crate) entities: EntityMap,
107 pub(crate) windows: SlotMap<WindowId, Option<Window>>,
108 pub(crate) pending_effects: VecDeque<Effect>,
109 pub(crate) observers: HashMap<EntityId, Handlers>,
110 pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
111}
112
113impl AppContext {
114 pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
115 self.pending_updates += 1;
116 let result = update(self);
117 if self.pending_updates == 1 {
118 self.flush_effects();
119 }
120 self.pending_updates -= 1;
121 result
122 }
123
124 pub(crate) fn update_window<R>(
125 &mut self,
126 id: WindowId,
127 update: impl FnOnce(&mut WindowContext) -> R,
128 ) -> Result<R> {
129 self.update(|cx| {
130 let mut window = cx
131 .windows
132 .get_mut(id)
133 .ok_or_else(|| anyhow!("window not found"))?
134 .take()
135 .unwrap();
136
137 let result = update(&mut WindowContext::mutable(cx, &mut window));
138
139 cx.windows
140 .get_mut(id)
141 .ok_or_else(|| anyhow!("window not found"))?
142 .replace(window);
143
144 Ok(result)
145 })
146 }
147
148 fn flush_effects(&mut self) {
149 dbg!("flush effects");
150 while let Some(effect) = self.pending_effects.pop_front() {
151 match effect {
152 Effect::Notify(entity_id) => self.apply_notify_effect(entity_id),
153 }
154 }
155
156 let dirty_window_ids = self
157 .windows
158 .iter()
159 .filter_map(|(window_id, window)| {
160 let window = window.as_ref().unwrap();
161 if window.dirty {
162 Some(window_id)
163 } else {
164 None
165 }
166 })
167 .collect::<Vec<_>>();
168
169 for dirty_window_id in dirty_window_ids {
170 self.update_window(dirty_window_id, |cx| cx.draw())
171 .unwrap()
172 .log_err();
173 }
174 }
175
176 fn apply_notify_effect(&mut self, updated_entity: EntityId) {
177 if let Some(mut handlers) = self.observers.remove(&updated_entity) {
178 handlers.retain(|handler| handler(self));
179 if let Some(new_handlers) = self.observers.remove(&updated_entity) {
180 handlers.extend(new_handlers);
181 }
182 self.observers.insert(updated_entity, handlers);
183 }
184 }
185
186 pub fn to_async(&self) -> AsyncAppContext {
187 AsyncAppContext(unsafe { mem::transmute(self.this.clone()) })
188 }
189
190 pub fn executor(&self) -> &Executor {
191 &self.executor
192 }
193
194 pub fn run_on_main<R>(
195 &mut self,
196 f: impl FnOnce(&mut MainThread<AppContext>) -> R + Send + 'static,
197 ) -> Task<R>
198 where
199 R: Send + 'static,
200 {
201 if self.executor.is_main_thread() {
202 Task::ready(f(unsafe {
203 mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(self)
204 }))
205 } else {
206 let this = self.this.upgrade().unwrap();
207 self.executor.run_on_main(move || {
208 let cx = &mut *this.lock();
209 cx.update(|cx| f(unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(cx) }))
210 })
211 }
212 }
213
214 pub fn spawn_on_main<F, R>(
215 &self,
216 f: impl FnOnce(&mut MainThread<AppContext>) -> F + Send + 'static,
217 ) -> Task<R>
218 where
219 F: Future<Output = R> + Send + 'static,
220 R: Send + 'static,
221 {
222 let this = self.this.upgrade().unwrap();
223 self.executor.spawn_on_main(move || {
224 let cx = &mut *this.lock();
225 cx.update(|cx| {
226 f(unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) })
227 })
228 })
229 }
230
231 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncAppContext) -> Fut + Send + 'static) -> Task<R>
232 where
233 Fut: Future<Output = R> + Send + 'static,
234 R: Send + 'static,
235 {
236 let cx = self.to_async();
237 self.executor.spawn(async move {
238 let future = f(cx);
239 future.await
240 })
241 }
242
243 pub fn text_system(&self) -> &Arc<TextSystem> {
244 &self.text_system
245 }
246
247 pub fn text_style(&self) -> TextStyle {
248 let mut style = TextStyle::default();
249 for refinement in &self.text_style_stack {
250 style.refine(refinement);
251 }
252 style
253 }
254
255 pub fn state<S: 'static>(&self) -> &S {
256 self.state_stacks_by_type
257 .get(&TypeId::of::<S>())
258 .and_then(|stack| stack.last())
259 .and_then(|any_state| any_state.downcast_ref::<S>())
260 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<S>()))
261 .unwrap()
262 }
263
264 pub fn state_mut<S: 'static>(&mut self) -> &mut S {
265 self.state_stacks_by_type
266 .get_mut(&TypeId::of::<S>())
267 .and_then(|stack| stack.last_mut())
268 .and_then(|any_state| any_state.downcast_mut::<S>())
269 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<S>()))
270 .unwrap()
271 }
272
273 pub(crate) fn push_text_style(&mut self, text_style: TextStyleRefinement) {
274 self.text_style_stack.push(text_style);
275 }
276
277 pub(crate) fn pop_text_style(&mut self) {
278 self.text_style_stack.pop();
279 }
280
281 pub(crate) fn push_state<T: Send + Sync + 'static>(&mut self, state: T) {
282 self.state_stacks_by_type
283 .entry(TypeId::of::<T>())
284 .or_default()
285 .push(Box::new(state));
286 }
287
288 pub(crate) fn pop_state<T: 'static>(&mut self) {
289 self.state_stacks_by_type
290 .get_mut(&TypeId::of::<T>())
291 .and_then(|stack| stack.pop())
292 .expect("state stack underflow");
293 }
294}
295
296impl Context for AppContext {
297 type EntityContext<'a, 'w, T: Send + Sync + 'static> = ModelContext<'a, T>;
298 type Result<T> = T;
299
300 fn entity<T: Send + Sync + 'static>(
301 &mut self,
302 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
303 ) -> Handle<T> {
304 self.update(|cx| {
305 let slot = cx.entities.reserve();
306 let entity = build_entity(&mut ModelContext::mutable(cx, slot.id));
307 cx.entities.insert(slot, entity)
308 })
309 }
310
311 fn update_entity<T: Send + Sync + 'static, R>(
312 &mut self,
313 handle: &Handle<T>,
314 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
315 ) -> R {
316 self.update(|cx| {
317 let mut entity = cx.entities.lease(handle);
318 let result = update(&mut entity, &mut ModelContext::mutable(cx, handle.id));
319 cx.entities.end_lease(entity);
320 result
321 })
322 }
323}
324
325impl MainThread<AppContext> {
326 fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
327 self.0.update(|cx| {
328 update(unsafe {
329 std::mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx)
330 })
331 })
332 }
333
334 pub(crate) fn update_window<R>(
335 &mut self,
336 id: WindowId,
337 update: impl FnOnce(&mut MainThread<WindowContext>) -> R,
338 ) -> Result<R> {
339 self.0.update_window(id, |cx| {
340 update(unsafe {
341 std::mem::transmute::<&mut WindowContext, &mut MainThread<WindowContext>>(cx)
342 })
343 })
344 }
345
346 pub(crate) fn platform(&self) -> &dyn Platform {
347 self.platform.borrow_on_main_thread()
348 }
349
350 pub fn activate(&mut self, ignoring_other_apps: bool) {
351 self.platform().activate(ignoring_other_apps);
352 }
353
354 pub fn open_window<S: 'static + Send + Sync>(
355 &mut self,
356 options: crate::WindowOptions,
357 build_root_view: impl FnOnce(&mut WindowContext) -> RootView<S> + Send + 'static,
358 ) -> WindowHandle<S> {
359 self.update(|cx| {
360 let id = cx.windows.insert(None);
361 let handle = WindowHandle::new(id);
362 let mut window = Window::new(handle.into(), options, cx);
363 let root_view = build_root_view(&mut WindowContext::mutable(cx, &mut window));
364 window.root_view.replace(root_view.into_any());
365 cx.windows.get_mut(id).unwrap().replace(window);
366 handle
367 })
368 }
369}
370
371pub(crate) enum Effect {
372 Notify(EntityId),
373}
374
375#[cfg(test)]
376mod tests {
377 use super::AppContext;
378
379 #[test]
380 fn test_app_context_send_sync() {
381 // This will not compile if `AppContext` does not implement `Send`
382 fn assert_send<T: Send>() {}
383 assert_send::<AppContext>();
384 }
385}