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, DisplayId, Executor, LayoutId,
12 MainThread, MainThreadOnly, Platform, PlatformDisplayLinker, RootView, SvgRenderer, Task,
13 TextStyle, 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 text_system: Arc::new(TextSystem::new(platform.text_system())),
60 pending_updates: 0,
61 display_linker: platform.display_linker(),
62 next_frame_callbacks: Default::default(),
63 platform: MainThreadOnly::new(platform, executor.clone()),
64 executor,
65 svg_renderer: SvgRenderer::new(asset_source),
66 image_cache: ImageCache::new(http_client),
67 text_style_stack: Vec::new(),
68 state_stacks_by_type: HashMap::default(),
69 unit_entity,
70 entities,
71 windows: SlotMap::with_key(),
72 pending_effects: Default::default(),
73 observers: Default::default(),
74 layout_id_buffer: Default::default(),
75 })
76 }))
77 }
78
79 pub fn run<F>(self, on_finish_launching: F)
80 where
81 F: 'static + FnOnce(&mut MainThread<AppContext>),
82 {
83 let this = self.clone();
84 let platform = self.0.lock().platform.clone();
85 platform.borrow_on_main_thread().run(Box::new(move || {
86 let cx = &mut *this.0.lock();
87 let cx = unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) };
88 on_finish_launching(cx);
89 }));
90 }
91}
92
93type Handlers = SmallVec<[Arc<dyn Fn(&mut AppContext) -> bool + Send + Sync + 'static>; 2]>;
94type FrameCallback = Box<dyn FnOnce(&mut WindowContext) + Send>;
95
96pub struct AppContext {
97 this: Weak<Mutex<AppContext>>,
98 platform: MainThreadOnly<dyn Platform>,
99 text_system: Arc<TextSystem>,
100 pending_updates: usize,
101 pub(crate) display_linker: Arc<dyn PlatformDisplayLinker>,
102 pub(crate) next_frame_callbacks: HashMap<DisplayId, Vec<FrameCallback>>,
103 pub(crate) executor: Executor,
104 pub(crate) svg_renderer: SvgRenderer,
105 pub(crate) image_cache: ImageCache,
106 pub(crate) text_style_stack: Vec<TextStyleRefinement>,
107 pub(crate) state_stacks_by_type: HashMap<TypeId, Vec<Box<dyn Any + Send + Sync>>>,
108 pub(crate) unit_entity: Handle<()>,
109 pub(crate) entities: EntityMap,
110 pub(crate) windows: SlotMap<WindowId, Option<Window>>,
111 pub(crate) pending_effects: VecDeque<Effect>,
112 pub(crate) observers: HashMap<EntityId, Handlers>,
113 pub(crate) layout_id_buffer: Vec<LayoutId>, // We recycle this memory across layout requests.
114}
115
116impl AppContext {
117 pub(crate) fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
118 self.pending_updates += 1;
119 let result = update(self);
120 if self.pending_updates == 1 {
121 self.flush_effects();
122 }
123 self.pending_updates -= 1;
124 result
125 }
126
127 pub(crate) fn update_window<R>(
128 &mut self,
129 id: WindowId,
130 update: impl FnOnce(&mut WindowContext) -> R,
131 ) -> Result<R> {
132 self.update(|cx| {
133 let mut window = cx
134 .windows
135 .get_mut(id)
136 .ok_or_else(|| anyhow!("window not found"))?
137 .take()
138 .unwrap();
139
140 let result = update(&mut WindowContext::mutable(cx, &mut window));
141
142 cx.windows
143 .get_mut(id)
144 .ok_or_else(|| anyhow!("window not found"))?
145 .replace(window);
146
147 Ok(result)
148 })
149 }
150
151 fn flush_effects(&mut self) {
152 while let Some(effect) = self.pending_effects.pop_front() {
153 match effect {
154 Effect::Notify(entity_id) => self.apply_notify_effect(entity_id),
155 }
156 }
157
158 let dirty_window_ids = self
159 .windows
160 .iter()
161 .filter_map(|(window_id, window)| {
162 let window = window.as_ref().unwrap();
163 if window.dirty {
164 Some(window_id)
165 } else {
166 None
167 }
168 })
169 .collect::<Vec<_>>();
170
171 for dirty_window_id in dirty_window_ids {
172 self.update_window(dirty_window_id, |cx| cx.draw())
173 .unwrap()
174 .log_err();
175 }
176 }
177
178 fn apply_notify_effect(&mut self, updated_entity: EntityId) {
179 if let Some(mut handlers) = self.observers.remove(&updated_entity) {
180 handlers.retain(|handler| handler(self));
181 if let Some(new_handlers) = self.observers.remove(&updated_entity) {
182 handlers.extend(new_handlers);
183 }
184 self.observers.insert(updated_entity, handlers);
185 }
186 }
187
188 pub fn to_async(&self) -> AsyncAppContext {
189 AsyncAppContext(unsafe { mem::transmute(self.this.clone()) })
190 }
191
192 pub fn executor(&self) -> &Executor {
193 &self.executor
194 }
195
196 pub fn run_on_main<R>(
197 &mut self,
198 f: impl FnOnce(&mut MainThread<AppContext>) -> R + Send + 'static,
199 ) -> Task<R>
200 where
201 R: Send + 'static,
202 {
203 if self.executor.is_main_thread() {
204 Task::ready(f(unsafe {
205 mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(self)
206 }))
207 } else {
208 let this = self.this.upgrade().unwrap();
209 self.executor.run_on_main(move || {
210 let cx = &mut *this.lock();
211 cx.update(|cx| f(unsafe { mem::transmute::<&mut Self, &mut MainThread<Self>>(cx) }))
212 })
213 }
214 }
215
216 pub fn spawn_on_main<F, R>(
217 &self,
218 f: impl FnOnce(&mut MainThread<AppContext>) -> F + Send + 'static,
219 ) -> Task<R>
220 where
221 F: Future<Output = R> + Send + 'static,
222 R: Send + 'static,
223 {
224 let this = self.this.upgrade().unwrap();
225 self.executor.spawn_on_main(move || {
226 let cx = &mut *this.lock();
227 cx.update(|cx| {
228 f(unsafe { mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx) })
229 })
230 })
231 }
232
233 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncAppContext) -> Fut + Send + 'static) -> Task<R>
234 where
235 Fut: Future<Output = R> + Send + 'static,
236 R: Send + 'static,
237 {
238 let cx = self.to_async();
239 self.executor.spawn(async move {
240 let future = f(cx);
241 future.await
242 })
243 }
244
245 pub fn text_system(&self) -> &Arc<TextSystem> {
246 &self.text_system
247 }
248
249 pub fn text_style(&self) -> TextStyle {
250 let mut style = TextStyle::default();
251 for refinement in &self.text_style_stack {
252 style.refine(refinement);
253 }
254 style
255 }
256
257 pub fn state<S: 'static>(&self) -> &S {
258 self.state_stacks_by_type
259 .get(&TypeId::of::<S>())
260 .and_then(|stack| stack.last())
261 .and_then(|any_state| any_state.downcast_ref::<S>())
262 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<S>()))
263 .unwrap()
264 }
265
266 pub fn state_mut<S: 'static>(&mut self) -> &mut S {
267 self.state_stacks_by_type
268 .get_mut(&TypeId::of::<S>())
269 .and_then(|stack| stack.last_mut())
270 .and_then(|any_state| any_state.downcast_mut::<S>())
271 .ok_or_else(|| anyhow!("no state of type {} exists", type_name::<S>()))
272 .unwrap()
273 }
274
275 pub(crate) fn push_text_style(&mut self, text_style: TextStyleRefinement) {
276 self.text_style_stack.push(text_style);
277 }
278
279 pub(crate) fn pop_text_style(&mut self) {
280 self.text_style_stack.pop();
281 }
282
283 pub(crate) fn push_state<T: Send + Sync + 'static>(&mut self, state: T) {
284 self.state_stacks_by_type
285 .entry(TypeId::of::<T>())
286 .or_default()
287 .push(Box::new(state));
288 }
289
290 pub(crate) fn pop_state<T: 'static>(&mut self) {
291 self.state_stacks_by_type
292 .get_mut(&TypeId::of::<T>())
293 .and_then(|stack| stack.pop())
294 .expect("state stack underflow");
295 }
296}
297
298impl Context for AppContext {
299 type EntityContext<'a, 'w, T: Send + Sync + 'static> = ModelContext<'a, T>;
300 type Result<T> = T;
301
302 fn entity<T: Send + Sync + 'static>(
303 &mut self,
304 build_entity: impl FnOnce(&mut Self::EntityContext<'_, '_, T>) -> T,
305 ) -> Handle<T> {
306 self.update(|cx| {
307 let slot = cx.entities.reserve();
308 let entity = build_entity(&mut ModelContext::mutable(cx, slot.id));
309 cx.entities.insert(slot, entity)
310 })
311 }
312
313 fn update_entity<T: Send + Sync + 'static, R>(
314 &mut self,
315 handle: &Handle<T>,
316 update: impl FnOnce(&mut T, &mut Self::EntityContext<'_, '_, T>) -> R,
317 ) -> R {
318 self.update(|cx| {
319 let mut entity = cx.entities.lease(handle);
320 let result = update(&mut entity, &mut ModelContext::mutable(cx, handle.id));
321 cx.entities.end_lease(entity);
322 result
323 })
324 }
325}
326
327impl MainThread<AppContext> {
328 fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
329 self.0.update(|cx| {
330 update(unsafe {
331 std::mem::transmute::<&mut AppContext, &mut MainThread<AppContext>>(cx)
332 })
333 })
334 }
335
336 pub(crate) fn update_window<R>(
337 &mut self,
338 id: WindowId,
339 update: impl FnOnce(&mut MainThread<WindowContext>) -> R,
340 ) -> Result<R> {
341 self.0.update_window(id, |cx| {
342 update(unsafe {
343 std::mem::transmute::<&mut WindowContext, &mut MainThread<WindowContext>>(cx)
344 })
345 })
346 }
347
348 pub(crate) fn platform(&self) -> &dyn Platform {
349 self.platform.borrow_on_main_thread()
350 }
351
352 pub fn activate(&mut self, ignoring_other_apps: bool) {
353 self.platform().activate(ignoring_other_apps);
354 }
355
356 pub fn open_window<S: 'static + Send + Sync>(
357 &mut self,
358 options: crate::WindowOptions,
359 build_root_view: impl FnOnce(&mut WindowContext) -> RootView<S> + Send + 'static,
360 ) -> WindowHandle<S> {
361 self.update(|cx| {
362 let id = cx.windows.insert(None);
363 let handle = WindowHandle::new(id);
364 let mut window = Window::new(handle.into(), options, cx);
365 let root_view = build_root_view(&mut WindowContext::mutable(cx, &mut window));
366 window.root_view.replace(root_view.into_any());
367 cx.windows.get_mut(id).unwrap().replace(window);
368 handle
369 })
370 }
371}
372
373pub(crate) enum Effect {
374 Notify(EntityId),
375}
376
377#[cfg(test)]
378mod tests {
379 use super::AppContext;
380
381 #[test]
382 fn test_app_context_send_sync() {
383 // This will not compile if `AppContext` does not implement `Send`
384 fn assert_send<T: Send>() {}
385 assert_send::<AppContext>();
386 }
387}