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