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