app.rs

   1use crate::{
   2    elements::ElementBox,
   3    executor,
   4    keymap::{self, Keystroke},
   5    platform::{self, WindowOptions},
   6    presenter::Presenter,
   7    util::{post_inc, timeout},
   8    AssetCache, AssetSource, ClipboardItem, FontCache, PathPromptOptions, TextLayoutCache,
   9};
  10use anyhow::{anyhow, Result};
  11use keymap::MatchResult;
  12use parking_lot::Mutex;
  13use pathfinder_geometry::{rect::RectF, vector::vec2f};
  14use platform::Event;
  15use postage::{sink::Sink as _, stream::Stream as _};
  16use smol::prelude::*;
  17use std::{
  18    any::{type_name, Any, TypeId},
  19    cell::RefCell,
  20    collections::{hash_map::Entry, HashMap, HashSet, VecDeque},
  21    fmt::{self, Debug},
  22    hash::{Hash, Hasher},
  23    marker::PhantomData,
  24    path::PathBuf,
  25    rc::{self, Rc},
  26    sync::{Arc, Weak},
  27    time::Duration,
  28};
  29
  30pub trait Entity: 'static + Send + Sync {
  31    type Event;
  32}
  33
  34pub trait View: Entity {
  35    fn ui_name() -> &'static str;
  36    fn render<'a>(&self, app: &AppContext) -> ElementBox;
  37    fn on_focus(&mut self, _ctx: &mut ViewContext<Self>) {}
  38    fn on_blur(&mut self, _ctx: &mut ViewContext<Self>) {}
  39    fn keymap_context(&self, _: &AppContext) -> keymap::Context {
  40        Self::default_keymap_context()
  41    }
  42    fn default_keymap_context() -> keymap::Context {
  43        let mut ctx = keymap::Context::default();
  44        ctx.set.insert(Self::ui_name().into());
  45        ctx
  46    }
  47}
  48
  49pub trait ReadModel {
  50    fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T;
  51}
  52
  53pub trait UpdateModel {
  54    fn update_model<T, F, S>(&mut self, handle: &ModelHandle<T>, update: F) -> S
  55    where
  56        T: Entity,
  57        F: FnOnce(&mut T, &mut ModelContext<T>) -> S;
  58}
  59
  60pub trait ReadView {
  61    fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T;
  62}
  63
  64pub trait UpdateView {
  65    fn update_view<T, F, S>(&mut self, handle: &ViewHandle<T>, update: F) -> S
  66    where
  67        T: View,
  68        F: FnOnce(&mut T, &mut ViewContext<T>) -> S;
  69}
  70
  71pub struct Menu<'a> {
  72    pub name: &'a str,
  73    pub items: Vec<MenuItem<'a>>,
  74}
  75
  76pub enum MenuItem<'a> {
  77    Action {
  78        name: &'a str,
  79        keystroke: Option<&'a str>,
  80        action: &'a str,
  81        arg: Option<Box<dyn Any + 'static>>,
  82    },
  83    Separator,
  84}
  85
  86#[derive(Clone)]
  87pub struct App(Rc<RefCell<MutableAppContext>>);
  88
  89#[derive(Clone)]
  90pub struct TestAppContext(Rc<RefCell<MutableAppContext>>);
  91
  92impl App {
  93    pub fn test<T, A: AssetSource, F: FnOnce(&mut MutableAppContext) -> T>(
  94        asset_source: A,
  95        f: F,
  96    ) -> T {
  97        let platform = platform::test::platform();
  98        let foreground = Rc::new(executor::Foreground::test());
  99        let ctx = Rc::new(RefCell::new(MutableAppContext::new(
 100            foreground,
 101            Rc::new(platform),
 102            asset_source,
 103        )));
 104        ctx.borrow_mut().weak_self = Some(Rc::downgrade(&ctx));
 105        let mut ctx = ctx.borrow_mut();
 106        f(&mut *ctx)
 107    }
 108
 109    pub fn test_async<T, F, A: AssetSource, Fn>(asset_source: A, f: Fn) -> T
 110    where
 111        Fn: FnOnce(TestAppContext) -> F,
 112        F: Future<Output = T>,
 113    {
 114        let platform = platform::test::platform();
 115        let foreground = Rc::new(executor::Foreground::test());
 116        let ctx = TestAppContext(Rc::new(RefCell::new(MutableAppContext::new(
 117            foreground.clone(),
 118            Rc::new(platform),
 119            asset_source,
 120        ))));
 121        ctx.0.borrow_mut().weak_self = Some(Rc::downgrade(&ctx.0));
 122
 123        let future = f(ctx);
 124        smol::block_on(foreground.run(future))
 125    }
 126
 127    pub fn new(asset_source: impl AssetSource) -> Result<Self> {
 128        let platform = platform::current::platform();
 129        let foreground = Rc::new(executor::Foreground::platform(platform.dispatcher())?);
 130        let app = Self(Rc::new(RefCell::new(MutableAppContext::new(
 131            foreground,
 132            platform.clone(),
 133            asset_source,
 134        ))));
 135
 136        let ctx = app.0.clone();
 137        platform.on_menu_command(Box::new(move |command, arg| {
 138            let mut ctx = ctx.borrow_mut();
 139            if let Some(key_window_id) = ctx.platform.key_window_id() {
 140                if let Some((presenter, _)) =
 141                    ctx.presenters_and_platform_windows.get(&key_window_id)
 142                {
 143                    let presenter = presenter.clone();
 144                    let path = presenter.borrow().dispatch_path(ctx.as_ref());
 145                    ctx.dispatch_action_any(key_window_id, &path, command, arg.unwrap_or(&()));
 146                } else {
 147                    ctx.dispatch_global_action_any(command, arg.unwrap_or(&()));
 148                }
 149            } else {
 150                ctx.dispatch_global_action_any(command, arg.unwrap_or(&()));
 151            }
 152        }));
 153
 154        app.0.borrow_mut().weak_self = Some(Rc::downgrade(&app.0));
 155        Ok(app)
 156    }
 157
 158    pub fn on_become_active<F>(self, mut callback: F) -> Self
 159    where
 160        F: 'static + FnMut(&mut MutableAppContext),
 161    {
 162        let ctx = self.0.clone();
 163        self.0
 164            .borrow()
 165            .platform
 166            .on_become_active(Box::new(move || callback(&mut *ctx.borrow_mut())));
 167        self
 168    }
 169
 170    pub fn on_resign_active<F>(self, mut callback: F) -> Self
 171    where
 172        F: 'static + FnMut(&mut MutableAppContext),
 173    {
 174        let ctx = self.0.clone();
 175        self.0
 176            .borrow()
 177            .platform
 178            .on_resign_active(Box::new(move || callback(&mut *ctx.borrow_mut())));
 179        self
 180    }
 181
 182    pub fn on_event<F>(self, mut callback: F) -> Self
 183    where
 184        F: 'static + FnMut(Event, &mut MutableAppContext) -> bool,
 185    {
 186        let ctx = self.0.clone();
 187        self.0.borrow().platform.on_event(Box::new(move |event| {
 188            callback(event, &mut *ctx.borrow_mut())
 189        }));
 190        self
 191    }
 192
 193    pub fn on_open_files<F>(self, mut callback: F) -> Self
 194    where
 195        F: 'static + FnMut(Vec<PathBuf>, &mut MutableAppContext),
 196    {
 197        let ctx = self.0.clone();
 198        self.0
 199            .borrow()
 200            .platform
 201            .on_open_files(Box::new(move |paths| {
 202                callback(paths, &mut *ctx.borrow_mut())
 203            }));
 204        self
 205    }
 206
 207    pub fn run<F>(self, on_finish_launching: F)
 208    where
 209        F: 'static + FnOnce(&mut MutableAppContext),
 210    {
 211        let platform = self.0.borrow().platform.clone();
 212        platform.run(Box::new(move || {
 213            let mut ctx = self.0.borrow_mut();
 214            on_finish_launching(&mut *ctx);
 215        }))
 216    }
 217
 218    pub fn font_cache(&self) -> Arc<FontCache> {
 219        self.0.borrow().font_cache.clone()
 220    }
 221
 222    fn update<T, F: FnOnce(&mut MutableAppContext) -> T>(&mut self, callback: F) -> T {
 223        let mut state = self.0.borrow_mut();
 224        state.pending_flushes += 1;
 225        let result = callback(&mut *state);
 226        state.flush_effects();
 227        result
 228    }
 229}
 230
 231impl TestAppContext {
 232    pub fn dispatch_action<T: 'static + Any>(
 233        &self,
 234        window_id: usize,
 235        responder_chain: Vec<usize>,
 236        name: &str,
 237        arg: T,
 238    ) {
 239        self.0.borrow_mut().dispatch_action_any(
 240            window_id,
 241            &responder_chain,
 242            name,
 243            Box::new(arg).as_ref(),
 244        );
 245    }
 246
 247    pub fn dispatch_keystroke(
 248        &self,
 249        window_id: usize,
 250        responder_chain: Vec<usize>,
 251        keystroke: &Keystroke,
 252    ) -> Result<bool> {
 253        let mut state = self.0.borrow_mut();
 254        state.dispatch_keystroke(window_id, responder_chain, keystroke)
 255    }
 256
 257    pub fn add_model<T, F>(&mut self, build_model: F) -> ModelHandle<T>
 258    where
 259        T: Entity,
 260        F: FnOnce(&mut ModelContext<T>) -> T,
 261    {
 262        let mut state = self.0.borrow_mut();
 263        state.pending_flushes += 1;
 264        let handle = state.add_model(build_model);
 265        state.flush_effects();
 266        handle
 267    }
 268
 269    pub fn add_window<T, F>(&mut self, build_root_view: F) -> (usize, ViewHandle<T>)
 270    where
 271        T: View,
 272        F: FnOnce(&mut ViewContext<T>) -> T,
 273    {
 274        self.0.borrow_mut().add_window(build_root_view)
 275    }
 276
 277    pub fn window_ids(&self) -> Vec<usize> {
 278        self.0.borrow().window_ids().collect()
 279    }
 280
 281    pub fn root_view<T: View>(&self, window_id: usize) -> Option<ViewHandle<T>> {
 282        self.0.borrow().root_view(window_id)
 283    }
 284
 285    pub fn add_view<T, F>(&mut self, window_id: usize, build_view: F) -> ViewHandle<T>
 286    where
 287        T: View,
 288        F: FnOnce(&mut ViewContext<T>) -> T,
 289    {
 290        let mut state = self.0.borrow_mut();
 291        state.pending_flushes += 1;
 292        let handle = state.add_view(window_id, build_view);
 293        state.flush_effects();
 294        handle
 295    }
 296
 297    pub fn add_option_view<T, F>(
 298        &mut self,
 299        window_id: usize,
 300        build_view: F,
 301    ) -> Option<ViewHandle<T>>
 302    where
 303        T: View,
 304        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
 305    {
 306        let mut state = self.0.borrow_mut();
 307        state.pending_flushes += 1;
 308        let handle = state.add_option_view(window_id, build_view);
 309        state.flush_effects();
 310        handle
 311    }
 312
 313    pub fn read<T, F: FnOnce(&AppContext) -> T>(&self, callback: F) -> T {
 314        callback(self.0.borrow().as_ref())
 315    }
 316
 317    pub fn update<T, F: FnOnce(&mut MutableAppContext) -> T>(&mut self, callback: F) -> T {
 318        let mut state = self.0.borrow_mut();
 319        // Don't increment pending flushes in order to effects to be flushed before the callback
 320        // completes, which is helpful in tests.
 321        let result = callback(&mut *state);
 322        // Flush effects after the callback just in case there are any. This can happen in edge
 323        // cases such as the closure dropping handles.
 324        state.flush_effects();
 325        result
 326    }
 327
 328    pub fn font_cache(&self) -> Arc<FontCache> {
 329        self.0.borrow().font_cache.clone()
 330    }
 331
 332    pub fn platform(&self) -> Rc<dyn platform::Platform> {
 333        self.0.borrow().platform.clone()
 334    }
 335}
 336
 337impl UpdateModel for TestAppContext {
 338    fn update_model<T, F, S>(&mut self, handle: &ModelHandle<T>, update: F) -> S
 339    where
 340        T: Entity,
 341        F: FnOnce(&mut T, &mut ModelContext<T>) -> S,
 342    {
 343        let mut state = self.0.borrow_mut();
 344        state.pending_flushes += 1;
 345        let result = state.update_model(handle, update);
 346        state.flush_effects();
 347        result
 348    }
 349}
 350
 351impl UpdateView for TestAppContext {
 352    fn update_view<T, F, S>(&mut self, handle: &ViewHandle<T>, update: F) -> S
 353    where
 354        T: View,
 355        F: FnOnce(&mut T, &mut ViewContext<T>) -> S,
 356    {
 357        let mut state = self.0.borrow_mut();
 358        state.pending_flushes += 1;
 359        let result = state.update_view(handle, update);
 360        state.flush_effects();
 361        result
 362    }
 363}
 364
 365type ActionCallback =
 366    dyn FnMut(&mut dyn AnyView, &dyn Any, &mut MutableAppContext, usize, usize) -> bool;
 367
 368type GlobalActionCallback = dyn FnMut(&dyn Any, &mut MutableAppContext);
 369
 370pub struct MutableAppContext {
 371    weak_self: Option<rc::Weak<RefCell<Self>>>,
 372    platform: Rc<dyn platform::Platform>,
 373    font_cache: Arc<FontCache>,
 374    assets: Arc<AssetCache>,
 375    ctx: AppContext,
 376    actions: HashMap<TypeId, HashMap<String, Vec<Box<ActionCallback>>>>,
 377    global_actions: HashMap<String, Vec<Box<GlobalActionCallback>>>,
 378    keystroke_matcher: keymap::Matcher,
 379    next_entity_id: usize,
 380    next_window_id: usize,
 381    next_task_id: usize,
 382    subscriptions: HashMap<usize, Vec<Subscription>>,
 383    observations: HashMap<usize, Vec<Observation>>,
 384    async_observations: HashMap<usize, postage::broadcast::Sender<()>>,
 385    window_invalidations: HashMap<usize, WindowInvalidation>,
 386    presenters_and_platform_windows:
 387        HashMap<usize, (Rc<RefCell<Presenter>>, Box<dyn platform::Window>)>,
 388    debug_elements_callbacks: HashMap<usize, Box<dyn Fn(&AppContext) -> crate::json::Value>>,
 389    foreground: Rc<executor::Foreground>,
 390    future_handlers: Rc<RefCell<HashMap<usize, FutureHandler>>>,
 391    stream_handlers: Rc<RefCell<HashMap<usize, StreamHandler>>>,
 392    pending_effects: VecDeque<Effect>,
 393    pending_flushes: usize,
 394    flushing_effects: bool,
 395}
 396
 397impl MutableAppContext {
 398    pub fn new(
 399        foreground: Rc<executor::Foreground>,
 400        platform: Rc<dyn platform::Platform>,
 401        asset_source: impl AssetSource,
 402    ) -> Self {
 403        let fonts = platform.fonts();
 404        Self {
 405            weak_self: None,
 406            platform,
 407            font_cache: Arc::new(FontCache::new(fonts)),
 408            assets: Arc::new(AssetCache::new(asset_source)),
 409            ctx: AppContext {
 410                models: Default::default(),
 411                windows: Default::default(),
 412                values: Default::default(),
 413                ref_counts: Arc::new(Mutex::new(RefCounts::default())),
 414                background: Arc::new(executor::Background::new()),
 415                thread_pool: scoped_pool::Pool::new(num_cpus::get(), "app"),
 416            },
 417            actions: HashMap::new(),
 418            global_actions: HashMap::new(),
 419            keystroke_matcher: keymap::Matcher::default(),
 420            next_entity_id: 0,
 421            next_window_id: 0,
 422            next_task_id: 0,
 423            subscriptions: HashMap::new(),
 424            observations: HashMap::new(),
 425            async_observations: HashMap::new(),
 426            window_invalidations: HashMap::new(),
 427            presenters_and_platform_windows: HashMap::new(),
 428            debug_elements_callbacks: HashMap::new(),
 429            foreground,
 430            future_handlers: Default::default(),
 431            stream_handlers: Default::default(),
 432            pending_effects: VecDeque::new(),
 433            pending_flushes: 0,
 434            flushing_effects: false,
 435        }
 436    }
 437
 438    pub fn upgrade(&self) -> App {
 439        App(self.weak_self.as_ref().unwrap().upgrade().unwrap())
 440    }
 441
 442    pub fn platform(&self) -> Rc<dyn platform::Platform> {
 443        self.platform.clone()
 444    }
 445
 446    pub fn font_cache(&self) -> &Arc<FontCache> {
 447        &self.font_cache
 448    }
 449
 450    pub fn foreground_executor(&self) -> &Rc<executor::Foreground> {
 451        &self.foreground
 452    }
 453
 454    pub fn background_executor(&self) -> &Arc<executor::Background> {
 455        &self.ctx.background
 456    }
 457
 458    pub fn on_debug_elements<F>(&mut self, window_id: usize, callback: F)
 459    where
 460        F: 'static + Fn(&AppContext) -> crate::json::Value,
 461    {
 462        self.debug_elements_callbacks
 463            .insert(window_id, Box::new(callback));
 464    }
 465
 466    pub fn debug_elements(&self, window_id: usize) -> Option<crate::json::Value> {
 467        self.debug_elements_callbacks
 468            .get(&window_id)
 469            .map(|debug_elements| debug_elements(&self.ctx))
 470    }
 471
 472    pub fn add_action<S, V, T, F>(&mut self, name: S, mut handler: F)
 473    where
 474        S: Into<String>,
 475        V: View,
 476        T: Any,
 477        F: 'static + FnMut(&mut V, &T, &mut ViewContext<V>),
 478    {
 479        let name = name.into();
 480        let name_clone = name.clone();
 481        let handler = Box::new(
 482            move |view: &mut dyn AnyView,
 483                  arg: &dyn Any,
 484                  app: &mut MutableAppContext,
 485                  window_id: usize,
 486                  view_id: usize| {
 487                match arg.downcast_ref() {
 488                    Some(arg) => {
 489                        let mut ctx = ViewContext::new(app, window_id, view_id);
 490                        handler(
 491                            view.as_any_mut()
 492                                .downcast_mut()
 493                                .expect("downcast is type safe"),
 494                            arg,
 495                            &mut ctx,
 496                        );
 497                        ctx.halt_action_dispatch
 498                    }
 499                    None => {
 500                        log::error!("Could not downcast argument for action {}", name_clone);
 501                        false
 502                    }
 503                }
 504            },
 505        );
 506
 507        self.actions
 508            .entry(TypeId::of::<V>())
 509            .or_default()
 510            .entry(name)
 511            .or_default()
 512            .push(handler);
 513    }
 514
 515    pub fn add_global_action<S, T, F>(&mut self, name: S, mut handler: F)
 516    where
 517        S: Into<String>,
 518        T: 'static + Any,
 519        F: 'static + FnMut(&T, &mut MutableAppContext),
 520    {
 521        let name = name.into();
 522        let name_clone = name.clone();
 523        let handler = Box::new(move |arg: &dyn Any, app: &mut MutableAppContext| {
 524            if let Some(arg) = arg.downcast_ref() {
 525                handler(arg, app);
 526            } else {
 527                log::error!("Could not downcast argument for action {}", name_clone);
 528            }
 529        });
 530
 531        self.global_actions.entry(name).or_default().push(handler);
 532    }
 533
 534    pub fn window_ids(&self) -> impl Iterator<Item = usize> + '_ {
 535        self.ctx.windows.keys().cloned()
 536    }
 537
 538    pub fn root_view<T: View>(&self, window_id: usize) -> Option<ViewHandle<T>> {
 539        self.ctx
 540            .windows
 541            .get(&window_id)
 542            .and_then(|window| window.root_view.as_ref().unwrap().clone().downcast::<T>())
 543    }
 544
 545    pub fn root_view_id(&self, window_id: usize) -> Option<usize> {
 546        self.ctx.root_view_id(window_id)
 547    }
 548
 549    pub fn focused_view_id(&self, window_id: usize) -> Option<usize> {
 550        self.ctx.focused_view_id(window_id)
 551    }
 552
 553    pub fn render_view(&self, window_id: usize, view_id: usize) -> Result<ElementBox> {
 554        self.ctx.render_view(window_id, view_id)
 555    }
 556
 557    pub fn render_views(&self, window_id: usize) -> Result<HashMap<usize, ElementBox>> {
 558        self.ctx.render_views(window_id)
 559    }
 560
 561    pub fn update<T, F: FnOnce() -> T>(&mut self, callback: F) -> T {
 562        self.pending_flushes += 1;
 563        let result = callback();
 564        self.flush_effects();
 565        result
 566    }
 567
 568    pub fn set_menus(&self, menus: Vec<Menu>) {
 569        self.platform.set_menus(menus);
 570    }
 571
 572    pub fn prompt_for_paths<F>(&self, options: PathPromptOptions, done_fn: F)
 573    where
 574        F: 'static + FnOnce(Option<Vec<PathBuf>>, &mut MutableAppContext),
 575    {
 576        let app = self.weak_self.as_ref().unwrap().upgrade().unwrap();
 577        let foreground = self.foreground.clone();
 578        self.platform().prompt_for_paths(
 579            options,
 580            Box::new(move |paths| {
 581                foreground
 582                    .spawn(async move { (done_fn)(paths, &mut *app.borrow_mut()) })
 583                    .detach();
 584            }),
 585        );
 586    }
 587
 588    pub fn dispatch_action<T: 'static + Any>(
 589        &mut self,
 590        window_id: usize,
 591        responder_chain: Vec<usize>,
 592        name: &str,
 593        arg: T,
 594    ) {
 595        self.dispatch_action_any(window_id, &responder_chain, name, Box::new(arg).as_ref());
 596    }
 597
 598    fn dispatch_action_any(
 599        &mut self,
 600        window_id: usize,
 601        path: &[usize],
 602        name: &str,
 603        arg: &dyn Any,
 604    ) -> bool {
 605        self.pending_flushes += 1;
 606        let mut halted_dispatch = false;
 607
 608        for view_id in path.iter().rev() {
 609            if let Some(mut view) = self
 610                .ctx
 611                .windows
 612                .get_mut(&window_id)
 613                .and_then(|w| w.views.remove(view_id))
 614            {
 615                let type_id = view.as_any().type_id();
 616
 617                if let Some((name, mut handlers)) = self
 618                    .actions
 619                    .get_mut(&type_id)
 620                    .and_then(|h| h.remove_entry(name))
 621                {
 622                    for handler in handlers.iter_mut().rev() {
 623                        let halt_dispatch = handler(view.as_mut(), arg, self, window_id, *view_id);
 624                        if halt_dispatch {
 625                            halted_dispatch = true;
 626                            break;
 627                        }
 628                    }
 629                    self.actions
 630                        .get_mut(&type_id)
 631                        .unwrap()
 632                        .insert(name, handlers);
 633                }
 634
 635                self.ctx
 636                    .windows
 637                    .get_mut(&window_id)
 638                    .unwrap()
 639                    .views
 640                    .insert(*view_id, view);
 641
 642                if halted_dispatch {
 643                    break;
 644                }
 645            }
 646        }
 647
 648        if !halted_dispatch {
 649            self.dispatch_global_action_any(name, arg);
 650        }
 651
 652        self.flush_effects();
 653        halted_dispatch
 654    }
 655
 656    pub fn dispatch_global_action<T: 'static + Any>(&mut self, name: &str, arg: T) {
 657        self.dispatch_global_action_any(name, Box::new(arg).as_ref());
 658    }
 659
 660    fn dispatch_global_action_any(&mut self, name: &str, arg: &dyn Any) {
 661        if let Some((name, mut handlers)) = self.global_actions.remove_entry(name) {
 662            self.pending_flushes += 1;
 663            for handler in handlers.iter_mut().rev() {
 664                handler(arg, self);
 665            }
 666            self.global_actions.insert(name, handlers);
 667            self.flush_effects();
 668        }
 669    }
 670
 671    pub fn add_bindings<T: IntoIterator<Item = keymap::Binding>>(&mut self, bindings: T) {
 672        self.keystroke_matcher.add_bindings(bindings);
 673    }
 674
 675    pub fn dispatch_keystroke(
 676        &mut self,
 677        window_id: usize,
 678        responder_chain: Vec<usize>,
 679        keystroke: &Keystroke,
 680    ) -> Result<bool> {
 681        let mut context_chain = Vec::new();
 682        let mut context = keymap::Context::default();
 683        for view_id in &responder_chain {
 684            if let Some(view) = self
 685                .ctx
 686                .windows
 687                .get(&window_id)
 688                .and_then(|w| w.views.get(view_id))
 689            {
 690                context.extend(view.keymap_context(self.as_ref()));
 691                context_chain.push(context.clone());
 692            } else {
 693                return Err(anyhow!(
 694                    "View {} in responder chain does not exist",
 695                    view_id
 696                ));
 697            }
 698        }
 699
 700        let mut pending = false;
 701        for (i, ctx) in context_chain.iter().enumerate().rev() {
 702            match self
 703                .keystroke_matcher
 704                .push_keystroke(keystroke.clone(), responder_chain[i], ctx)
 705            {
 706                MatchResult::None => {}
 707                MatchResult::Pending => pending = true,
 708                MatchResult::Action { name, arg } => {
 709                    if self.dispatch_action_any(
 710                        window_id,
 711                        &responder_chain[0..=i],
 712                        &name,
 713                        arg.as_ref().map(|arg| arg.as_ref()).unwrap_or(&()),
 714                    ) {
 715                        return Ok(true);
 716                    }
 717                }
 718            }
 719        }
 720
 721        Ok(pending)
 722    }
 723
 724    pub fn add_model<T, F>(&mut self, build_model: F) -> ModelHandle<T>
 725    where
 726        T: Entity,
 727        F: FnOnce(&mut ModelContext<T>) -> T,
 728    {
 729        self.pending_flushes += 1;
 730        let model_id = post_inc(&mut self.next_entity_id);
 731        let mut ctx = ModelContext::new(self, model_id);
 732        let model = build_model(&mut ctx);
 733        self.ctx.models.insert(model_id, Box::new(model));
 734        self.flush_effects();
 735        ModelHandle::new(model_id, &self.ctx.ref_counts)
 736    }
 737
 738    pub fn add_window<T, F>(&mut self, build_root_view: F) -> (usize, ViewHandle<T>)
 739    where
 740        T: View,
 741        F: FnOnce(&mut ViewContext<T>) -> T,
 742    {
 743        self.pending_flushes += 1;
 744        let window_id = post_inc(&mut self.next_window_id);
 745        self.ctx.windows.insert(window_id, Window::default());
 746        self.open_platform_window(window_id);
 747        let root_handle = self.add_view(window_id, build_root_view);
 748        self.ctx.windows.get_mut(&window_id).unwrap().root_view = Some(root_handle.clone().into());
 749        self.focus(window_id, root_handle.id());
 750        self.flush_effects();
 751
 752        (window_id, root_handle)
 753    }
 754
 755    fn open_platform_window(&mut self, window_id: usize) {
 756        let mut window = self.platform.open_window(
 757            window_id,
 758            WindowOptions {
 759                bounds: RectF::new(vec2f(0., 0.), vec2f(1024., 768.)),
 760                title: "Zed".into(),
 761            },
 762            self.foreground.clone(),
 763        );
 764        let text_layout_cache = TextLayoutCache::new(self.platform.fonts());
 765        let presenter = Rc::new(RefCell::new(Presenter::new(
 766            window_id,
 767            self.font_cache.clone(),
 768            text_layout_cache,
 769            self.assets.clone(),
 770            self,
 771        )));
 772
 773        {
 774            let mut app = self.upgrade();
 775            let presenter = presenter.clone();
 776            window.on_event(Box::new(move |event| {
 777                app.update(|ctx| {
 778                    if let Event::KeyDown { keystroke, .. } = &event {
 779                        if ctx
 780                            .dispatch_keystroke(
 781                                window_id,
 782                                presenter.borrow().dispatch_path(ctx.as_ref()),
 783                                keystroke,
 784                            )
 785                            .unwrap()
 786                        {
 787                            return;
 788                        }
 789                    }
 790
 791                    let actions = presenter.borrow_mut().dispatch_event(event, ctx.as_ref());
 792                    for action in actions {
 793                        ctx.dispatch_action_any(
 794                            window_id,
 795                            &action.path,
 796                            action.name,
 797                            action.arg.as_ref(),
 798                        );
 799                    }
 800                })
 801            }));
 802        }
 803
 804        {
 805            let mut app = self.upgrade();
 806            let presenter = presenter.clone();
 807            window.on_resize(Box::new(move |window| {
 808                app.update(|ctx| {
 809                    let scene = presenter.borrow_mut().build_scene(
 810                        window.size(),
 811                        window.scale_factor(),
 812                        ctx,
 813                    );
 814                    window.present_scene(scene);
 815                })
 816            }));
 817        }
 818
 819        self.presenters_and_platform_windows
 820            .insert(window_id, (presenter.clone(), window));
 821
 822        self.on_debug_elements(window_id, move |ctx| {
 823            presenter.borrow().debug_elements(ctx).unwrap()
 824        });
 825    }
 826
 827    pub fn add_view<T, F>(&mut self, window_id: usize, build_view: F) -> ViewHandle<T>
 828    where
 829        T: View,
 830        F: FnOnce(&mut ViewContext<T>) -> T,
 831    {
 832        self.add_option_view(window_id, |ctx| Some(build_view(ctx)))
 833            .unwrap()
 834    }
 835
 836    pub fn add_option_view<T, F>(
 837        &mut self,
 838        window_id: usize,
 839        build_view: F,
 840    ) -> Option<ViewHandle<T>>
 841    where
 842        T: View,
 843        F: FnOnce(&mut ViewContext<T>) -> Option<T>,
 844    {
 845        let view_id = post_inc(&mut self.next_entity_id);
 846        self.pending_flushes += 1;
 847        let mut ctx = ViewContext::new(self, window_id, view_id);
 848        let handle = if let Some(view) = build_view(&mut ctx) {
 849            if let Some(window) = self.ctx.windows.get_mut(&window_id) {
 850                window.views.insert(view_id, Box::new(view));
 851            } else {
 852                panic!("Window does not exist");
 853            }
 854            self.window_invalidations
 855                .entry(window_id)
 856                .or_default()
 857                .updated
 858                .insert(view_id);
 859            Some(ViewHandle::new(window_id, view_id, &self.ctx.ref_counts))
 860        } else {
 861            None
 862        };
 863        self.flush_effects();
 864        handle
 865    }
 866
 867    fn remove_dropped_entities(&mut self) {
 868        loop {
 869            let (dropped_models, dropped_views, dropped_values) = self.ctx.ref_counts.lock().take_dropped();
 870            if dropped_models.is_empty() && dropped_views.is_empty() && dropped_values.is_empty() {
 871                break;
 872            }
 873
 874            for model_id in dropped_models {
 875                self.ctx.models.remove(&model_id);
 876                self.subscriptions.remove(&model_id);
 877                self.observations.remove(&model_id);
 878                self.async_observations.remove(&model_id);
 879            }
 880
 881            for (window_id, view_id) in dropped_views {
 882                self.subscriptions.remove(&view_id);
 883                self.observations.remove(&view_id);
 884                self.async_observations.remove(&view_id);
 885                if let Some(window) = self.ctx.windows.get_mut(&window_id) {
 886                    self.window_invalidations
 887                        .entry(window_id)
 888                        .or_default()
 889                        .removed
 890                        .push(view_id);
 891                    window.views.remove(&view_id);
 892                }
 893            }
 894
 895            let mut values = self.ctx.values.lock();
 896            for key in dropped_values {
 897                values.remove(&key);
 898            }
 899        }
 900    }
 901
 902    fn flush_effects(&mut self) {
 903        self.pending_flushes = self.pending_flushes.saturating_sub(1);
 904
 905        if !self.flushing_effects && self.pending_flushes == 0 {
 906            self.flushing_effects = true;
 907
 908            while let Some(effect) = self.pending_effects.pop_front() {
 909                match effect {
 910                    Effect::Event { entity_id, payload } => self.emit_event(entity_id, payload),
 911                    Effect::ModelNotification { model_id } => self.notify_model_observers(model_id),
 912                    Effect::ViewNotification { window_id, view_id } => {
 913                        self.notify_view_observers(window_id, view_id)
 914                    }
 915                    Effect::Focus { window_id, view_id } => {
 916                        self.focus(window_id, view_id);
 917                    }
 918                }
 919            }
 920
 921            self.flushing_effects = false;
 922            self.remove_dropped_entities();
 923            self.update_windows();
 924        }
 925    }
 926
 927    fn update_windows(&mut self) {
 928        let mut invalidations = HashMap::new();
 929        std::mem::swap(&mut invalidations, &mut self.window_invalidations);
 930
 931        for (window_id, invalidation) in invalidations {
 932            if let Some((presenter, mut window)) =
 933                self.presenters_and_platform_windows.remove(&window_id)
 934            {
 935                {
 936                    let mut presenter = presenter.borrow_mut();
 937                    presenter.invalidate(invalidation, self.as_ref());
 938                    let scene = presenter.build_scene(window.size(), window.scale_factor(), self);
 939                    window.present_scene(scene);
 940                }
 941                self.presenters_and_platform_windows
 942                    .insert(window_id, (presenter, window));
 943            }
 944        }
 945    }
 946
 947    fn emit_event(&mut self, entity_id: usize, payload: Box<dyn Any>) {
 948        if let Some(subscriptions) = self.subscriptions.remove(&entity_id) {
 949            for mut subscription in subscriptions {
 950                let alive = match &mut subscription {
 951                    Subscription::FromModel { model_id, callback } => {
 952                        if let Some(mut model) = self.ctx.models.remove(model_id) {
 953                            callback(model.as_any_mut(), payload.as_ref(), self, *model_id);
 954                            self.ctx.models.insert(*model_id, model);
 955                            true
 956                        } else {
 957                            false
 958                        }
 959                    }
 960                    Subscription::FromView {
 961                        window_id,
 962                        view_id,
 963                        callback,
 964                    } => {
 965                        if let Some(mut view) = self
 966                            .ctx
 967                            .windows
 968                            .get_mut(&window_id)
 969                            .and_then(|window| window.views.remove(view_id))
 970                        {
 971                            callback(
 972                                view.as_any_mut(),
 973                                payload.as_ref(),
 974                                self,
 975                                *window_id,
 976                                *view_id,
 977                            );
 978                            self.ctx
 979                                .windows
 980                                .get_mut(&window_id)
 981                                .unwrap()
 982                                .views
 983                                .insert(*view_id, view);
 984                            true
 985                        } else {
 986                            false
 987                        }
 988                    }
 989                };
 990
 991                if alive {
 992                    self.subscriptions
 993                        .entry(entity_id)
 994                        .or_default()
 995                        .push(subscription);
 996                }
 997            }
 998        }
 999    }
1000
1001    fn notify_model_observers(&mut self, observed_id: usize) {
1002        if let Some(observations) = self.observations.remove(&observed_id) {
1003            if self.ctx.models.contains_key(&observed_id) {
1004                for mut observation in observations {
1005                    let alive = match &mut observation {
1006                        Observation::FromModel { model_id, callback } => {
1007                            if let Some(mut model) = self.ctx.models.remove(model_id) {
1008                                callback(model.as_any_mut(), observed_id, self, *model_id);
1009                                self.ctx.models.insert(*model_id, model);
1010                                true
1011                            } else {
1012                                false
1013                            }
1014                        }
1015                        Observation::FromView {
1016                            window_id,
1017                            view_id,
1018                            callback,
1019                        } => {
1020                            if let Some(mut view) = self
1021                                .ctx
1022                                .windows
1023                                .get_mut(window_id)
1024                                .and_then(|w| w.views.remove(view_id))
1025                            {
1026                                callback(
1027                                    view.as_any_mut(),
1028                                    observed_id,
1029                                    self,
1030                                    *window_id,
1031                                    *view_id,
1032                                );
1033                                self.ctx
1034                                    .windows
1035                                    .get_mut(window_id)
1036                                    .unwrap()
1037                                    .views
1038                                    .insert(*view_id, view);
1039                                true
1040                            } else {
1041                                false
1042                            }
1043                        }
1044                    };
1045
1046                    if alive {
1047                        self.observations
1048                            .entry(observed_id)
1049                            .or_default()
1050                            .push(observation);
1051                    }
1052                }
1053            }
1054        }
1055
1056        if let Entry::Occupied(mut entry) = self.async_observations.entry(observed_id) {
1057            if entry.get_mut().blocking_send(()).is_err() {
1058                entry.remove_entry();
1059            }
1060        }
1061    }
1062
1063    fn notify_view_observers(&mut self, window_id: usize, view_id: usize) {
1064        self.window_invalidations
1065            .entry(window_id)
1066            .or_default()
1067            .updated
1068            .insert(view_id);
1069
1070        if let Entry::Occupied(mut entry) = self.async_observations.entry(view_id) {
1071            if entry.get_mut().blocking_send(()).is_err() {
1072                entry.remove_entry();
1073            }
1074        }
1075    }
1076
1077    fn focus(&mut self, window_id: usize, focused_id: usize) {
1078        if self
1079            .ctx
1080            .windows
1081            .get(&window_id)
1082            .and_then(|w| w.focused_view)
1083            .map_or(false, |cur_focused| cur_focused == focused_id)
1084        {
1085            return;
1086        }
1087
1088        self.pending_flushes += 1;
1089
1090        if let Some((blurred_id, mut blurred)) =
1091            self.ctx.windows.get_mut(&window_id).and_then(|w| {
1092                let blurred_view = w.focused_view;
1093                w.focused_view = Some(focused_id);
1094                blurred_view.and_then(|id| w.views.remove(&id).map(|view| (id, view)))
1095            })
1096        {
1097            blurred.on_blur(self, window_id, blurred_id);
1098            self.ctx
1099                .windows
1100                .get_mut(&window_id)
1101                .unwrap()
1102                .views
1103                .insert(blurred_id, blurred);
1104        }
1105
1106        if let Some(mut focused) = self
1107            .ctx
1108            .windows
1109            .get_mut(&window_id)
1110            .and_then(|w| w.views.remove(&focused_id))
1111        {
1112            focused.on_focus(self, window_id, focused_id);
1113            self.ctx
1114                .windows
1115                .get_mut(&window_id)
1116                .unwrap()
1117                .views
1118                .insert(focused_id, focused);
1119        }
1120
1121        self.flush_effects();
1122    }
1123
1124    fn spawn<F, T>(&mut self, future: F) -> EntityTask<T>
1125    where
1126        F: 'static + Future,
1127        T: 'static,
1128    {
1129        let task_id = post_inc(&mut self.next_task_id);
1130        let app = self.weak_self.as_ref().unwrap().upgrade().unwrap();
1131        let task = {
1132            let app = app.clone();
1133            self.foreground.spawn(async move {
1134                let output = future.await;
1135                *app.borrow_mut()
1136                    .handle_future_output(task_id, Box::new(output))
1137                    .downcast::<T>()
1138                    .unwrap()
1139            })
1140        };
1141        EntityTask::new(
1142            task_id,
1143            task,
1144            TaskHandlerMap::Future(self.future_handlers.clone()),
1145        )
1146    }
1147
1148    fn spawn_stream<F, T>(&mut self, mut stream: F) -> EntityTask<T>
1149    where
1150        F: 'static + Stream + Unpin,
1151        T: 'static,
1152    {
1153        let task_id = post_inc(&mut self.next_task_id);
1154        let app = self.weak_self.as_ref().unwrap().upgrade().unwrap();
1155        let task = self.foreground.spawn(async move {
1156            loop {
1157                match stream.next().await {
1158                    Some(item) => {
1159                        let mut app = app.borrow_mut();
1160                        if app.handle_stream_item(task_id, Box::new(item)) {
1161                            break;
1162                        }
1163                    }
1164                    None => {
1165                        break;
1166                    }
1167                }
1168            }
1169
1170            *app.borrow_mut()
1171                .stream_completed(task_id)
1172                .downcast::<T>()
1173                .unwrap()
1174        });
1175
1176        EntityTask::new(
1177            task_id,
1178            task,
1179            TaskHandlerMap::Stream(self.stream_handlers.clone()),
1180        )
1181    }
1182
1183    fn handle_future_output(&mut self, task_id: usize, output: Box<dyn Any>) -> Box<dyn Any> {
1184        self.pending_flushes += 1;
1185        let future_callback = self.future_handlers.borrow_mut().remove(&task_id).unwrap();
1186        let result = future_callback(output, self);
1187        self.flush_effects();
1188        result
1189    }
1190
1191    fn handle_stream_item(&mut self, task_id: usize, output: Box<dyn Any>) -> bool {
1192        self.pending_flushes += 1;
1193
1194        let mut handler = self.stream_handlers.borrow_mut().remove(&task_id).unwrap();
1195        let halt = (handler.item_callback)(output, self);
1196        self.stream_handlers.borrow_mut().insert(task_id, handler);
1197
1198        self.flush_effects();
1199        halt
1200    }
1201
1202    fn stream_completed(&mut self, task_id: usize) -> Box<dyn Any> {
1203        self.pending_flushes += 1;
1204
1205        let handler = self.stream_handlers.borrow_mut().remove(&task_id).unwrap();
1206        let result = (handler.done_callback)(self);
1207
1208        self.flush_effects();
1209        result
1210    }
1211
1212    pub fn write_to_clipboard(&self, item: ClipboardItem) {
1213        self.platform.write_to_clipboard(item);
1214    }
1215
1216    pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
1217        self.platform.read_from_clipboard()
1218    }
1219}
1220
1221impl ReadModel for MutableAppContext {
1222    fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
1223        if let Some(model) = self.ctx.models.get(&handle.model_id) {
1224            model
1225                .as_any()
1226                .downcast_ref()
1227                .expect("Downcast is type safe")
1228        } else {
1229            panic!("Circular model reference");
1230        }
1231    }
1232}
1233
1234impl UpdateModel for MutableAppContext {
1235    fn update_model<T, F, S>(&mut self, handle: &ModelHandle<T>, update: F) -> S
1236    where
1237        T: Entity,
1238        F: FnOnce(&mut T, &mut ModelContext<T>) -> S,
1239    {
1240        if let Some(mut model) = self.ctx.models.remove(&handle.model_id) {
1241            self.pending_flushes += 1;
1242            let mut ctx = ModelContext::new(self, handle.model_id);
1243            let result = update(
1244                model
1245                    .as_any_mut()
1246                    .downcast_mut()
1247                    .expect("Downcast is type safe"),
1248                &mut ctx,
1249            );
1250            self.ctx.models.insert(handle.model_id, model);
1251            self.flush_effects();
1252            result
1253        } else {
1254            panic!("Circular model update");
1255        }
1256    }
1257}
1258
1259impl ReadView for MutableAppContext {
1260    fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
1261        if let Some(window) = self.ctx.windows.get(&handle.window_id) {
1262            if let Some(view) = window.views.get(&handle.view_id) {
1263                view.as_any().downcast_ref().expect("Downcast is type safe")
1264            } else {
1265                panic!("Circular view reference");
1266            }
1267        } else {
1268            panic!("Window does not exist");
1269        }
1270    }
1271}
1272
1273impl UpdateView for MutableAppContext {
1274    fn update_view<T, F, S>(&mut self, handle: &ViewHandle<T>, update: F) -> S
1275    where
1276        T: View,
1277        F: FnOnce(&mut T, &mut ViewContext<T>) -> S,
1278    {
1279        self.pending_flushes += 1;
1280        let mut view = if let Some(window) = self.ctx.windows.get_mut(&handle.window_id) {
1281            if let Some(view) = window.views.remove(&handle.view_id) {
1282                view
1283            } else {
1284                panic!("Circular view update");
1285            }
1286        } else {
1287            panic!("Window does not exist");
1288        };
1289
1290        let mut ctx = ViewContext::new(self, handle.window_id, handle.view_id);
1291        let result = update(
1292            view.as_any_mut()
1293                .downcast_mut()
1294                .expect("Downcast is type safe"),
1295            &mut ctx,
1296        );
1297        self.ctx
1298            .windows
1299            .get_mut(&handle.window_id)
1300            .unwrap()
1301            .views
1302            .insert(handle.view_id, view);
1303        self.flush_effects();
1304        result
1305    }
1306}
1307
1308impl AsRef<AppContext> for MutableAppContext {
1309    fn as_ref(&self) -> &AppContext {
1310        &self.ctx
1311    }
1312}
1313
1314pub struct AppContext {
1315    models: HashMap<usize, Box<dyn AnyModel>>,
1316    windows: HashMap<usize, Window>,
1317    values: Mutex<HashMap<(TypeId, usize), Box<dyn Any>>>,
1318    background: Arc<executor::Background>,
1319    ref_counts: Arc<Mutex<RefCounts>>,
1320    thread_pool: scoped_pool::Pool,
1321}
1322
1323impl AppContext {
1324    pub fn root_view_id(&self, window_id: usize) -> Option<usize> {
1325        self.windows
1326            .get(&window_id)
1327            .and_then(|window| window.root_view.as_ref().map(|v| v.id()))
1328    }
1329
1330    pub fn focused_view_id(&self, window_id: usize) -> Option<usize> {
1331        self.windows
1332            .get(&window_id)
1333            .and_then(|window| window.focused_view)
1334    }
1335
1336    pub fn render_view(&self, window_id: usize, view_id: usize) -> Result<ElementBox> {
1337        self.windows
1338            .get(&window_id)
1339            .and_then(|w| w.views.get(&view_id))
1340            .map(|v| v.render(self))
1341            .ok_or(anyhow!("view not found"))
1342    }
1343
1344    pub fn render_views(&self, window_id: usize) -> Result<HashMap<usize, ElementBox>> {
1345        self.windows
1346            .get(&window_id)
1347            .map(|w| {
1348                w.views
1349                    .iter()
1350                    .map(|(id, view)| (*id, view.render(self)))
1351                    .collect::<HashMap<_, ElementBox>>()
1352            })
1353            .ok_or(anyhow!("window not found"))
1354    }
1355
1356    pub fn background_executor(&self) -> &Arc<executor::Background> {
1357        &self.background
1358    }
1359
1360    pub fn thread_pool(&self) -> &scoped_pool::Pool {
1361        &self.thread_pool
1362    }
1363
1364    pub fn value<T: 'static + Default, Tag: 'static>(&self, id: usize) -> ValueHandle<T> {
1365        let key = (TypeId::of::<Tag>(), id);
1366        let mut values = self.values.lock();
1367        values.entry(key).or_insert_with(|| Box::new(T::default()));
1368        ValueHandle::new(TypeId::of::<Tag>(), id, &self.ref_counts)
1369    }
1370}
1371
1372impl ReadModel for AppContext {
1373    fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
1374        if let Some(model) = self.models.get(&handle.model_id) {
1375            model
1376                .as_any()
1377                .downcast_ref()
1378                .expect("downcast should be type safe")
1379        } else {
1380            panic!("circular model reference");
1381        }
1382    }
1383}
1384
1385impl ReadView for AppContext {
1386    fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
1387        if let Some(window) = self.windows.get(&handle.window_id) {
1388            if let Some(view) = window.views.get(&handle.view_id) {
1389                view.as_any()
1390                    .downcast_ref()
1391                    .expect("downcast should be type safe")
1392            } else {
1393                panic!("circular view reference");
1394            }
1395        } else {
1396            panic!("window does not exist");
1397        }
1398    }
1399}
1400
1401#[derive(Default)]
1402struct Window {
1403    views: HashMap<usize, Box<dyn AnyView>>,
1404    root_view: Option<AnyViewHandle>,
1405    focused_view: Option<usize>,
1406}
1407
1408#[derive(Default, Clone)]
1409pub struct WindowInvalidation {
1410    pub updated: HashSet<usize>,
1411    pub removed: Vec<usize>,
1412}
1413
1414pub enum Effect {
1415    Event {
1416        entity_id: usize,
1417        payload: Box<dyn Any>,
1418    },
1419    ModelNotification {
1420        model_id: usize,
1421    },
1422    ViewNotification {
1423        window_id: usize,
1424        view_id: usize,
1425    },
1426    Focus {
1427        window_id: usize,
1428        view_id: usize,
1429    },
1430}
1431
1432pub trait AnyModel: Send + Sync {
1433    fn as_any(&self) -> &dyn Any;
1434    fn as_any_mut(&mut self) -> &mut dyn Any;
1435}
1436
1437impl<T> AnyModel for T
1438where
1439    T: Entity,
1440{
1441    fn as_any(&self) -> &dyn Any {
1442        self
1443    }
1444
1445    fn as_any_mut(&mut self) -> &mut dyn Any {
1446        self
1447    }
1448}
1449
1450pub trait AnyView: Send + Sync {
1451    fn as_any(&self) -> &dyn Any;
1452    fn as_any_mut(&mut self) -> &mut dyn Any;
1453    fn ui_name(&self) -> &'static str;
1454    fn render<'a>(&self, app: &AppContext) -> ElementBox;
1455    fn on_focus(&mut self, app: &mut MutableAppContext, window_id: usize, view_id: usize);
1456    fn on_blur(&mut self, app: &mut MutableAppContext, window_id: usize, view_id: usize);
1457    fn keymap_context(&self, app: &AppContext) -> keymap::Context;
1458}
1459
1460impl<T> AnyView for T
1461where
1462    T: View,
1463{
1464    fn as_any(&self) -> &dyn Any {
1465        self
1466    }
1467
1468    fn as_any_mut(&mut self) -> &mut dyn Any {
1469        self
1470    }
1471
1472    fn ui_name(&self) -> &'static str {
1473        T::ui_name()
1474    }
1475
1476    fn render<'a>(&self, app: &AppContext) -> ElementBox {
1477        View::render(self, app)
1478    }
1479
1480    fn on_focus(&mut self, app: &mut MutableAppContext, window_id: usize, view_id: usize) {
1481        let mut ctx = ViewContext::new(app, window_id, view_id);
1482        View::on_focus(self, &mut ctx);
1483    }
1484
1485    fn on_blur(&mut self, app: &mut MutableAppContext, window_id: usize, view_id: usize) {
1486        let mut ctx = ViewContext::new(app, window_id, view_id);
1487        View::on_blur(self, &mut ctx);
1488    }
1489
1490    fn keymap_context(&self, app: &AppContext) -> keymap::Context {
1491        View::keymap_context(self, app)
1492    }
1493}
1494
1495pub struct ModelContext<'a, T: ?Sized> {
1496    app: &'a mut MutableAppContext,
1497    model_id: usize,
1498    model_type: PhantomData<T>,
1499    halt_stream: bool,
1500}
1501
1502impl<'a, T: Entity> ModelContext<'a, T> {
1503    fn new(app: &'a mut MutableAppContext, model_id: usize) -> Self {
1504        Self {
1505            app,
1506            model_id,
1507            model_type: PhantomData,
1508            halt_stream: false,
1509        }
1510    }
1511
1512    pub fn background_executor(&self) -> &Arc<executor::Background> {
1513        &self.app.ctx.background
1514    }
1515
1516    pub fn thread_pool(&self) -> &scoped_pool::Pool {
1517        &self.app.ctx.thread_pool
1518    }
1519
1520    pub fn halt_stream(&mut self) {
1521        self.halt_stream = true;
1522    }
1523
1524    pub fn model_id(&self) -> usize {
1525        self.model_id
1526    }
1527
1528    pub fn add_model<S, F>(&mut self, build_model: F) -> ModelHandle<S>
1529    where
1530        S: Entity,
1531        F: FnOnce(&mut ModelContext<S>) -> S,
1532    {
1533        self.app.add_model(build_model)
1534    }
1535
1536    pub fn subscribe<S: Entity, F>(&mut self, handle: &ModelHandle<S>, mut callback: F)
1537    where
1538        S::Event: 'static,
1539        F: 'static + FnMut(&mut T, &S::Event, &mut ModelContext<T>),
1540    {
1541        self.app
1542            .subscriptions
1543            .entry(handle.model_id)
1544            .or_default()
1545            .push(Subscription::FromModel {
1546                model_id: self.model_id,
1547                callback: Box::new(move |model, payload, app, model_id| {
1548                    let model = model.downcast_mut().expect("downcast is type safe");
1549                    let payload = payload.downcast_ref().expect("downcast is type safe");
1550                    let mut ctx = ModelContext::new(app, model_id);
1551                    callback(model, payload, &mut ctx);
1552                }),
1553            });
1554    }
1555
1556    pub fn emit(&mut self, payload: T::Event) {
1557        self.app.pending_effects.push_back(Effect::Event {
1558            entity_id: self.model_id,
1559            payload: Box::new(payload),
1560        });
1561    }
1562
1563    pub fn observe<S, F>(&mut self, handle: &ModelHandle<S>, mut callback: F)
1564    where
1565        S: Entity,
1566        F: 'static + FnMut(&mut T, ModelHandle<S>, &mut ModelContext<T>),
1567    {
1568        self.app
1569            .observations
1570            .entry(handle.model_id)
1571            .or_default()
1572            .push(Observation::FromModel {
1573                model_id: self.model_id,
1574                callback: Box::new(move |model, observed_id, app, model_id| {
1575                    let model = model.downcast_mut().expect("downcast is type safe");
1576                    let observed = ModelHandle::new(observed_id, &app.ctx.ref_counts);
1577                    let mut ctx = ModelContext::new(app, model_id);
1578                    callback(model, observed, &mut ctx);
1579                }),
1580            });
1581    }
1582
1583    pub fn notify(&mut self) {
1584        self.app
1585            .pending_effects
1586            .push_back(Effect::ModelNotification {
1587                model_id: self.model_id,
1588            });
1589    }
1590
1591    fn handle(&self) -> ModelHandle<T> {
1592        ModelHandle::new(self.model_id, &self.app.ctx.ref_counts)
1593    }
1594
1595    pub fn spawn<S, F, U>(&mut self, future: S, callback: F) -> EntityTask<U>
1596    where
1597        S: 'static + Future,
1598        F: 'static + FnOnce(&mut T, S::Output, &mut ModelContext<T>) -> U,
1599        U: 'static,
1600    {
1601        let handle = self.handle();
1602        let task = self.app.spawn::<S, U>(future);
1603
1604        self.app.future_handlers.borrow_mut().insert(
1605            task.id,
1606            Box::new(move |output, ctx| {
1607                let output = *output.downcast().unwrap();
1608                handle.update(ctx, |model, ctx| Box::new(callback(model, output, ctx)))
1609            }),
1610        );
1611
1612        task
1613    }
1614
1615    pub fn spawn_stream<S, F, G, U>(
1616        &mut self,
1617        stream: S,
1618        mut item_callback: F,
1619        done_callback: G,
1620    ) -> EntityTask<U>
1621    where
1622        S: 'static + Stream + Unpin,
1623        F: 'static + FnMut(&mut T, S::Item, &mut ModelContext<T>),
1624        G: 'static + FnOnce(&mut T, &mut ModelContext<T>) -> U,
1625        U: 'static + Any,
1626    {
1627        let handle = self.handle();
1628        let task = self.app.spawn_stream(stream);
1629
1630        self.app.stream_handlers.borrow_mut().insert(
1631            task.id,
1632            StreamHandler {
1633                item_callback: {
1634                    let handle = handle.clone();
1635                    Box::new(move |output, app| {
1636                        let output = *output.downcast().unwrap();
1637                        handle.update(app, |model, ctx| {
1638                            item_callback(model, output, ctx);
1639                            ctx.halt_stream
1640                        })
1641                    })
1642                },
1643                done_callback: Box::new(move |app| {
1644                    handle.update(app, |model, ctx| Box::new(done_callback(model, ctx)))
1645                }),
1646            },
1647        );
1648
1649        task
1650    }
1651}
1652
1653impl<M> AsRef<AppContext> for ModelContext<'_, M> {
1654    fn as_ref(&self) -> &AppContext {
1655        &self.app.ctx
1656    }
1657}
1658
1659impl<M> AsMut<MutableAppContext> for ModelContext<'_, M> {
1660    fn as_mut(&mut self) -> &mut MutableAppContext {
1661        self.app
1662    }
1663}
1664
1665impl<M> ReadModel for ModelContext<'_, M> {
1666    fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
1667        self.app.read_model(handle)
1668    }
1669}
1670
1671impl<M> UpdateModel for ModelContext<'_, M> {
1672    fn update_model<T, F, S>(&mut self, handle: &ModelHandle<T>, update: F) -> S
1673    where
1674        T: Entity,
1675        F: FnOnce(&mut T, &mut ModelContext<T>) -> S,
1676    {
1677        self.app.update_model(handle, update)
1678    }
1679}
1680
1681pub struct ViewContext<'a, T: ?Sized> {
1682    app: &'a mut MutableAppContext,
1683    window_id: usize,
1684    view_id: usize,
1685    view_type: PhantomData<T>,
1686    halt_action_dispatch: bool,
1687    halt_stream: bool,
1688}
1689
1690impl<'a, T: View> ViewContext<'a, T> {
1691    fn new(app: &'a mut MutableAppContext, window_id: usize, view_id: usize) -> Self {
1692        Self {
1693            app,
1694            window_id,
1695            view_id,
1696            view_type: PhantomData,
1697            halt_action_dispatch: true,
1698            halt_stream: false,
1699        }
1700    }
1701
1702    pub fn handle(&self) -> ViewHandle<T> {
1703        ViewHandle::new(self.window_id, self.view_id, &self.app.ctx.ref_counts)
1704    }
1705
1706    pub fn window_id(&self) -> usize {
1707        self.window_id
1708    }
1709
1710    pub fn background_executor(&self) -> &Arc<executor::Background> {
1711        &self.app.ctx.background
1712    }
1713
1714    pub fn debug_elements(&self) -> crate::json::Value {
1715        self.app.debug_elements(self.window_id).unwrap()
1716    }
1717
1718    pub fn focus<S>(&mut self, handle: S)
1719    where
1720        S: Into<AnyViewHandle>,
1721    {
1722        let handle = handle.into();
1723        self.app.pending_effects.push_back(Effect::Focus {
1724            window_id: handle.window_id,
1725            view_id: handle.view_id,
1726        });
1727    }
1728
1729    pub fn focus_self(&mut self) {
1730        self.app.pending_effects.push_back(Effect::Focus {
1731            window_id: self.window_id,
1732            view_id: self.view_id,
1733        });
1734    }
1735
1736    pub fn add_model<S, F>(&mut self, build_model: F) -> ModelHandle<S>
1737    where
1738        S: Entity,
1739        F: FnOnce(&mut ModelContext<S>) -> S,
1740    {
1741        self.app.add_model(build_model)
1742    }
1743
1744    pub fn add_view<S, F>(&mut self, build_view: F) -> ViewHandle<S>
1745    where
1746        S: View,
1747        F: FnOnce(&mut ViewContext<S>) -> S,
1748    {
1749        self.app.add_view(self.window_id, build_view)
1750    }
1751
1752    pub fn add_option_view<S, F>(&mut self, build_view: F) -> Option<ViewHandle<S>>
1753    where
1754        S: View,
1755        F: FnOnce(&mut ViewContext<S>) -> Option<S>,
1756    {
1757        self.app.add_option_view(self.window_id, build_view)
1758    }
1759
1760    pub fn subscribe_to_model<E, F>(&mut self, handle: &ModelHandle<E>, mut callback: F)
1761    where
1762        E: Entity,
1763        E::Event: 'static,
1764        F: 'static + FnMut(&mut T, ModelHandle<E>, &E::Event, &mut ViewContext<T>),
1765    {
1766        let emitter_handle = handle.downgrade();
1767        self.app
1768            .subscriptions
1769            .entry(handle.id())
1770            .or_default()
1771            .push(Subscription::FromView {
1772                window_id: self.window_id,
1773                view_id: self.view_id,
1774                callback: Box::new(move |view, payload, app, window_id, view_id| {
1775                    if let Some(emitter_handle) = emitter_handle.upgrade(app.as_ref()) {
1776                        let model = view.downcast_mut().expect("downcast is type safe");
1777                        let payload = payload.downcast_ref().expect("downcast is type safe");
1778                        let mut ctx = ViewContext::new(app, window_id, view_id);
1779                        callback(model, emitter_handle, payload, &mut ctx);
1780                    }
1781                }),
1782            });
1783    }
1784
1785    pub fn subscribe_to_view<V, F>(&mut self, handle: &ViewHandle<V>, mut callback: F)
1786    where
1787        V: View,
1788        V::Event: 'static,
1789        F: 'static + FnMut(&mut T, ViewHandle<V>, &V::Event, &mut ViewContext<T>),
1790    {
1791        let emitter_handle = handle.downgrade();
1792
1793        self.app
1794            .subscriptions
1795            .entry(handle.id())
1796            .or_default()
1797            .push(Subscription::FromView {
1798                window_id: self.window_id,
1799                view_id: self.view_id,
1800                callback: Box::new(move |view, payload, app, window_id, view_id| {
1801                    if let Some(emitter_handle) = emitter_handle.upgrade(app.as_ref()) {
1802                        let model = view.downcast_mut().expect("downcast is type safe");
1803                        let payload = payload.downcast_ref().expect("downcast is type safe");
1804                        let mut ctx = ViewContext::new(app, window_id, view_id);
1805                        callback(model, emitter_handle, payload, &mut ctx);
1806                    }
1807                }),
1808            });
1809    }
1810
1811    pub fn emit(&mut self, payload: T::Event) {
1812        self.app.pending_effects.push_back(Effect::Event {
1813            entity_id: self.view_id,
1814            payload: Box::new(payload),
1815        });
1816    }
1817
1818    pub fn observe<S, F>(&mut self, handle: &ModelHandle<S>, mut callback: F)
1819    where
1820        S: Entity,
1821        F: 'static + FnMut(&mut T, ModelHandle<S>, &mut ViewContext<T>),
1822    {
1823        self.app
1824            .observations
1825            .entry(handle.id())
1826            .or_default()
1827            .push(Observation::FromView {
1828                window_id: self.window_id,
1829                view_id: self.view_id,
1830                callback: Box::new(move |view, observed_id, app, window_id, view_id| {
1831                    let view = view.downcast_mut().expect("downcast is type safe");
1832                    let observed = ModelHandle::new(observed_id, &app.ctx.ref_counts);
1833                    let mut ctx = ViewContext::new(app, window_id, view_id);
1834                    callback(view, observed, &mut ctx);
1835                }),
1836            });
1837    }
1838
1839    pub fn notify(&mut self) {
1840        self.app
1841            .pending_effects
1842            .push_back(Effect::ViewNotification {
1843                window_id: self.window_id,
1844                view_id: self.view_id,
1845            });
1846    }
1847
1848    pub fn propagate_action(&mut self) {
1849        self.halt_action_dispatch = false;
1850    }
1851
1852    pub fn halt_stream(&mut self) {
1853        self.halt_stream = true;
1854    }
1855
1856    pub fn spawn<S, F, U>(&mut self, future: S, callback: F) -> EntityTask<U>
1857    where
1858        S: 'static + Future,
1859        F: 'static + FnOnce(&mut T, S::Output, &mut ViewContext<T>) -> U,
1860        U: 'static,
1861    {
1862        let handle = self.handle();
1863        let task = self.app.spawn(future);
1864
1865        self.app.future_handlers.borrow_mut().insert(
1866            task.id,
1867            Box::new(move |output, app| {
1868                let output = *output.downcast().unwrap();
1869                handle.update(app, |view, ctx| Box::new(callback(view, output, ctx)))
1870            }),
1871        );
1872
1873        task
1874    }
1875
1876    pub fn spawn_stream<S, F, G, U>(
1877        &mut self,
1878        stream: S,
1879        mut item_callback: F,
1880        done_callback: G,
1881    ) -> EntityTask<U>
1882    where
1883        S: 'static + Stream + Unpin,
1884        F: 'static + FnMut(&mut T, S::Item, &mut ViewContext<T>),
1885        G: 'static + FnOnce(&mut T, &mut ViewContext<T>) -> U,
1886        U: 'static + Any,
1887    {
1888        let handle = self.handle();
1889        let task = self.app.spawn_stream(stream);
1890        self.app.stream_handlers.borrow_mut().insert(
1891            task.id,
1892            StreamHandler {
1893                item_callback: {
1894                    let handle = handle.clone();
1895                    Box::new(move |output, app| {
1896                        let output = *output.downcast().unwrap();
1897                        handle.update(app, |view, ctx| {
1898                            item_callback(view, output, ctx);
1899                            ctx.halt_stream
1900                        })
1901                    })
1902                },
1903                done_callback: Box::new(move |app| {
1904                    handle.update(app, |view, ctx| Box::new(done_callback(view, ctx)))
1905                }),
1906            },
1907        );
1908        task
1909    }
1910}
1911
1912impl<M> AsRef<AppContext> for ViewContext<'_, M> {
1913    fn as_ref(&self) -> &AppContext {
1914        &self.app.ctx
1915    }
1916}
1917
1918impl<M> AsMut<MutableAppContext> for ViewContext<'_, M> {
1919    fn as_mut(&mut self) -> &mut MutableAppContext {
1920        self.app
1921    }
1922}
1923
1924impl<V> ReadModel for ViewContext<'_, V> {
1925    fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
1926        self.app.read_model(handle)
1927    }
1928}
1929
1930impl<V: View> UpdateModel for ViewContext<'_, V> {
1931    fn update_model<T, F, S>(&mut self, handle: &ModelHandle<T>, update: F) -> S
1932    where
1933        T: Entity,
1934        F: FnOnce(&mut T, &mut ModelContext<T>) -> S,
1935    {
1936        self.app.update_model(handle, update)
1937    }
1938}
1939
1940impl<V: View> ReadView for ViewContext<'_, V> {
1941    fn read_view<T: View>(&self, handle: &ViewHandle<T>) -> &T {
1942        self.app.read_view(handle)
1943    }
1944}
1945
1946impl<V: View> UpdateView for ViewContext<'_, V> {
1947    fn update_view<T, F, S>(&mut self, handle: &ViewHandle<T>, update: F) -> S
1948    where
1949        T: View,
1950        F: FnOnce(&mut T, &mut ViewContext<T>) -> S,
1951    {
1952        self.app.update_view(handle, update)
1953    }
1954}
1955
1956pub trait Handle<T> {
1957    fn id(&self) -> usize;
1958    fn location(&self) -> EntityLocation;
1959}
1960
1961#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
1962pub enum EntityLocation {
1963    Model(usize),
1964    View(usize, usize),
1965}
1966
1967pub struct ModelHandle<T> {
1968    model_id: usize,
1969    model_type: PhantomData<T>,
1970    ref_counts: Weak<Mutex<RefCounts>>,
1971}
1972
1973impl<T: Entity> ModelHandle<T> {
1974    fn new(model_id: usize, ref_counts: &Arc<Mutex<RefCounts>>) -> Self {
1975        ref_counts.lock().inc_entity(model_id);
1976        Self {
1977            model_id,
1978            model_type: PhantomData,
1979            ref_counts: Arc::downgrade(ref_counts),
1980        }
1981    }
1982
1983    fn downgrade(&self) -> WeakModelHandle<T> {
1984        WeakModelHandle::new(self.model_id)
1985    }
1986
1987    pub fn id(&self) -> usize {
1988        self.model_id
1989    }
1990
1991    pub fn read<'a, A: ReadModel>(&self, app: &'a A) -> &'a T {
1992        app.read_model(self)
1993    }
1994
1995    pub fn update<A, F, S>(&self, app: &mut A, update: F) -> S
1996    where
1997        A: UpdateModel,
1998        F: FnOnce(&mut T, &mut ModelContext<T>) -> S,
1999    {
2000        app.update_model(self, update)
2001    }
2002
2003    pub fn condition(
2004        &self,
2005        ctx: &TestAppContext,
2006        mut predicate: impl 'static + FnMut(&T, &AppContext) -> bool,
2007    ) -> impl 'static + Future<Output = ()> {
2008        let mut ctx = ctx.0.borrow_mut();
2009        let tx = ctx
2010            .async_observations
2011            .entry(self.id())
2012            .or_insert_with(|| postage::broadcast::channel(128).0);
2013        let mut rx = tx.subscribe();
2014        let ctx = ctx.weak_self.as_ref().unwrap().upgrade().unwrap();
2015        let handle = self.downgrade();
2016
2017        async move {
2018            timeout(Duration::from_millis(200), async move {
2019                loop {
2020                    {
2021                        let ctx = ctx.borrow();
2022                        let ctx = ctx.as_ref();
2023                        if predicate(
2024                            handle
2025                                .upgrade(ctx)
2026                                .expect("model dropped with pending condition")
2027                                .read(ctx),
2028                            ctx,
2029                        ) {
2030                            break;
2031                        }
2032                    }
2033
2034                    rx.recv()
2035                        .await
2036                        .expect("model dropped with pending condition");
2037                }
2038            })
2039            .await
2040            .expect("condition timed out");
2041        }
2042    }
2043}
2044
2045impl<T> Clone for ModelHandle<T> {
2046    fn clone(&self) -> Self {
2047        if let Some(ref_counts) = self.ref_counts.upgrade() {
2048            ref_counts.lock().inc_entity(self.model_id);
2049        }
2050
2051        Self {
2052            model_id: self.model_id,
2053            model_type: PhantomData,
2054            ref_counts: self.ref_counts.clone(),
2055        }
2056    }
2057}
2058
2059impl<T> PartialEq for ModelHandle<T> {
2060    fn eq(&self, other: &Self) -> bool {
2061        self.model_id == other.model_id
2062    }
2063}
2064
2065impl<T> Eq for ModelHandle<T> {}
2066
2067impl<T> Hash for ModelHandle<T> {
2068    fn hash<H: Hasher>(&self, state: &mut H) {
2069        self.model_id.hash(state);
2070    }
2071}
2072
2073impl<T> std::borrow::Borrow<usize> for ModelHandle<T> {
2074    fn borrow(&self) -> &usize {
2075        &self.model_id
2076    }
2077}
2078
2079impl<T> Debug for ModelHandle<T> {
2080    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2081        f.debug_tuple(&format!("ModelHandle<{}>", type_name::<T>()))
2082            .field(&self.model_id)
2083            .finish()
2084    }
2085}
2086
2087unsafe impl<T> Send for ModelHandle<T> {}
2088unsafe impl<T> Sync for ModelHandle<T> {}
2089
2090impl<T> Drop for ModelHandle<T> {
2091    fn drop(&mut self) {
2092        if let Some(ref_counts) = self.ref_counts.upgrade() {
2093            ref_counts.lock().dec_model(self.model_id);
2094        }
2095    }
2096}
2097
2098impl<T> Handle<T> for ModelHandle<T> {
2099    fn id(&self) -> usize {
2100        self.model_id
2101    }
2102
2103    fn location(&self) -> EntityLocation {
2104        EntityLocation::Model(self.model_id)
2105    }
2106}
2107
2108pub struct WeakModelHandle<T> {
2109    model_id: usize,
2110    model_type: PhantomData<T>,
2111}
2112
2113impl<T: Entity> WeakModelHandle<T> {
2114    fn new(model_id: usize) -> Self {
2115        Self {
2116            model_id,
2117            model_type: PhantomData,
2118        }
2119    }
2120
2121    pub fn upgrade(&self, app: &AppContext) -> Option<ModelHandle<T>> {
2122        if app.models.contains_key(&self.model_id) {
2123            Some(ModelHandle::new(self.model_id, &app.ref_counts))
2124        } else {
2125            None
2126        }
2127    }
2128}
2129
2130pub struct ViewHandle<T> {
2131    window_id: usize,
2132    view_id: usize,
2133    view_type: PhantomData<T>,
2134    ref_counts: Weak<Mutex<RefCounts>>,
2135}
2136
2137impl<T: View> ViewHandle<T> {
2138    fn new(window_id: usize, view_id: usize, ref_counts: &Arc<Mutex<RefCounts>>) -> Self {
2139        ref_counts.lock().inc_entity(view_id);
2140        Self {
2141            window_id,
2142            view_id,
2143            view_type: PhantomData,
2144            ref_counts: Arc::downgrade(ref_counts),
2145        }
2146    }
2147
2148    pub fn downgrade(&self) -> WeakViewHandle<T> {
2149        WeakViewHandle::new(self.window_id, self.view_id)
2150    }
2151
2152    pub fn window_id(&self) -> usize {
2153        self.window_id
2154    }
2155
2156    pub fn id(&self) -> usize {
2157        self.view_id
2158    }
2159
2160    pub fn read<'a, A: ReadView>(&self, app: &'a A) -> &'a T {
2161        app.read_view(self)
2162    }
2163
2164    pub fn update<A, F, S>(&self, app: &mut A, update: F) -> S
2165    where
2166        A: UpdateView,
2167        F: FnOnce(&mut T, &mut ViewContext<T>) -> S,
2168    {
2169        app.update_view(self, update)
2170    }
2171
2172    pub fn is_focused(&self, app: &AppContext) -> bool {
2173        app.focused_view_id(self.window_id)
2174            .map_or(false, |focused_id| focused_id == self.view_id)
2175    }
2176
2177    pub fn condition(
2178        &self,
2179        ctx: &TestAppContext,
2180        mut predicate: impl 'static + FnMut(&T, &AppContext) -> bool,
2181    ) -> impl 'static + Future<Output = ()> {
2182        let mut ctx = ctx.0.borrow_mut();
2183        let tx = ctx
2184            .async_observations
2185            .entry(self.id())
2186            .or_insert_with(|| postage::broadcast::channel(128).0);
2187        let mut rx = tx.subscribe();
2188        let ctx = ctx.weak_self.as_ref().unwrap().upgrade().unwrap();
2189        let handle = self.downgrade();
2190
2191        async move {
2192            timeout(Duration::from_millis(200), async move {
2193                loop {
2194                    {
2195                        let ctx = ctx.borrow();
2196                        let ctx = ctx.as_ref();
2197                        if predicate(
2198                            handle
2199                                .upgrade(ctx)
2200                                .expect("model dropped with pending condition")
2201                                .read(ctx),
2202                            ctx,
2203                        ) {
2204                            break;
2205                        }
2206                    }
2207
2208                    rx.recv()
2209                        .await
2210                        .expect("model dropped with pending condition");
2211                }
2212            })
2213            .await
2214            .expect("condition timed out");
2215        }
2216    }
2217}
2218
2219impl<T> Clone for ViewHandle<T> {
2220    fn clone(&self) -> Self {
2221        if let Some(ref_counts) = self.ref_counts.upgrade() {
2222            ref_counts.lock().inc_entity(self.view_id);
2223        }
2224
2225        Self {
2226            window_id: self.window_id,
2227            view_id: self.view_id,
2228            view_type: PhantomData,
2229            ref_counts: self.ref_counts.clone(),
2230        }
2231    }
2232}
2233
2234impl<T> PartialEq for ViewHandle<T> {
2235    fn eq(&self, other: &Self) -> bool {
2236        self.window_id == other.window_id && self.view_id == other.view_id
2237    }
2238}
2239
2240impl<T> Eq for ViewHandle<T> {}
2241
2242impl<T> Debug for ViewHandle<T> {
2243    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2244        f.debug_struct(&format!("ViewHandle<{}>", type_name::<T>()))
2245            .field("window_id", &self.window_id)
2246            .field("view_id", &self.view_id)
2247            .finish()
2248    }
2249}
2250
2251impl<T> Drop for ViewHandle<T> {
2252    fn drop(&mut self) {
2253        if let Some(ref_counts) = self.ref_counts.upgrade() {
2254            ref_counts.lock().dec_view(self.window_id, self.view_id);
2255        }
2256    }
2257}
2258
2259impl<T> Handle<T> for ViewHandle<T> {
2260    fn id(&self) -> usize {
2261        self.view_id
2262    }
2263
2264    fn location(&self) -> EntityLocation {
2265        EntityLocation::View(self.window_id, self.view_id)
2266    }
2267}
2268
2269#[derive(Clone)]
2270pub struct AnyViewHandle {
2271    window_id: usize,
2272    view_id: usize,
2273    view_type: TypeId,
2274    ref_counts: Weak<Mutex<RefCounts>>,
2275}
2276
2277impl AnyViewHandle {
2278    pub fn id(&self) -> usize {
2279        self.view_id
2280    }
2281
2282    pub fn is<T: 'static>(&self) -> bool {
2283        TypeId::of::<T>() == self.view_type
2284    }
2285
2286    pub fn downcast<T: View>(self) -> Option<ViewHandle<T>> {
2287        if self.is::<T>() {
2288            if let Some(ref_counts) = self.ref_counts.upgrade() {
2289                return Some(ViewHandle::new(self.window_id, self.view_id, &ref_counts));
2290            }
2291        }
2292        None
2293    }
2294}
2295
2296impl<T: View> From<&ViewHandle<T>> for AnyViewHandle {
2297    fn from(handle: &ViewHandle<T>) -> Self {
2298        if let Some(ref_counts) = handle.ref_counts.upgrade() {
2299            ref_counts.lock().inc_entity(handle.view_id);
2300        }
2301        AnyViewHandle {
2302            window_id: handle.window_id,
2303            view_id: handle.view_id,
2304            view_type: TypeId::of::<T>(),
2305            ref_counts: handle.ref_counts.clone(),
2306        }
2307    }
2308}
2309
2310impl<T: View> From<ViewHandle<T>> for AnyViewHandle {
2311    fn from(handle: ViewHandle<T>) -> Self {
2312        (&handle).into()
2313    }
2314}
2315
2316pub struct WeakViewHandle<T> {
2317    window_id: usize,
2318    view_id: usize,
2319    view_type: PhantomData<T>,
2320}
2321
2322impl<T: View> WeakViewHandle<T> {
2323    fn new(window_id: usize, view_id: usize) -> Self {
2324        Self {
2325            window_id,
2326            view_id,
2327            view_type: PhantomData,
2328        }
2329    }
2330
2331    pub fn upgrade(&self, app: &AppContext) -> Option<ViewHandle<T>> {
2332        if app
2333            .windows
2334            .get(&self.window_id)
2335            .and_then(|w| w.views.get(&self.view_id))
2336            .is_some()
2337        {
2338            Some(ViewHandle::new(
2339                self.window_id,
2340                self.view_id,
2341                &app.ref_counts,
2342            ))
2343        } else {
2344            None
2345        }
2346    }
2347}
2348
2349impl<T> Clone for WeakViewHandle<T> {
2350    fn clone(&self) -> Self {
2351        Self {
2352            window_id: self.window_id,
2353            view_id: self.view_id,
2354            view_type: PhantomData,
2355        }
2356    }
2357}
2358
2359pub struct ValueHandle<T> {
2360    value_type: PhantomData<T>,
2361    tag_type_id: TypeId,
2362    id: usize,
2363    ref_counts: Weak<Mutex<RefCounts>>,
2364}
2365
2366impl<T: 'static> ValueHandle<T> {
2367    fn new(tag_type_id: TypeId, id: usize, ref_counts: &Arc<Mutex<RefCounts>>) -> Self {
2368        ref_counts.lock().inc_value(tag_type_id, id);
2369        Self {
2370            value_type: PhantomData,
2371            tag_type_id,
2372            id,
2373            ref_counts: Arc::downgrade(ref_counts),
2374        }
2375    }
2376
2377    pub fn map<R>(&self, ctx: &AppContext, f: impl FnOnce(&mut T) -> R) -> R {
2378        f(ctx
2379            .values
2380            .lock()
2381            .get_mut(&(self.tag_type_id, self.id))
2382            .unwrap()
2383            .downcast_mut()
2384            .unwrap())
2385    }
2386}
2387
2388impl<T> Drop for ValueHandle<T> {
2389    fn drop(&mut self) {
2390        if let Some(ref_counts) = self.ref_counts.upgrade() {
2391            ref_counts.lock().dec_value(self.tag_type_id, self.id);
2392        }
2393    }
2394}
2395
2396#[derive(Default)]
2397struct RefCounts {
2398    entity_counts: HashMap<usize, usize>,
2399    value_counts: HashMap<(TypeId, usize), usize>,
2400    dropped_models: HashSet<usize>,
2401    dropped_views: HashSet<(usize, usize)>,
2402    dropped_values: HashSet<(TypeId, usize)>,
2403}
2404
2405impl RefCounts {
2406    fn inc_entity(&mut self, model_id: usize) {
2407        *self.entity_counts.entry(model_id).or_insert(0) += 1;
2408    }
2409
2410    fn inc_value(&mut self, tag_type_id: TypeId, id: usize) {
2411        *self.value_counts.entry((tag_type_id, id)).or_insert(0) += 1;
2412    }
2413
2414    fn dec_model(&mut self, model_id: usize) {
2415        let count = self.entity_counts.get_mut(&model_id).unwrap();
2416        *count -= 1;
2417        if *count == 0 {
2418            self.entity_counts.remove(&model_id);
2419            self.dropped_models.insert(model_id);
2420        }
2421    }
2422
2423    fn dec_view(&mut self, window_id: usize, view_id: usize) {
2424        let count = self.entity_counts.get_mut(&view_id).unwrap();
2425        *count -= 1;
2426        if *count == 0 {
2427            self.entity_counts.remove(&view_id);
2428            self.dropped_views.insert((window_id, view_id));
2429        }
2430    }
2431
2432    fn dec_value(&mut self, tag_type_id: TypeId, id: usize) {
2433        let key = (tag_type_id, id);
2434        let count = self.value_counts.get_mut(&key).unwrap();
2435        *count -= 1;
2436        if *count == 0 {
2437            self.value_counts.remove(&key);
2438            self.dropped_values.insert(key);
2439        }
2440    }
2441
2442    fn take_dropped(&mut self) -> (HashSet<usize>, HashSet<(usize, usize)>, HashSet<(TypeId, usize)>) {
2443        let mut dropped_models = HashSet::new();
2444        let mut dropped_views = HashSet::new();
2445        let mut dropped_values = HashSet::new();
2446        std::mem::swap(&mut self.dropped_models, &mut dropped_models);
2447        std::mem::swap(&mut self.dropped_views, &mut dropped_views);
2448        std::mem::swap(&mut self.dropped_values, &mut dropped_values);
2449        (dropped_models, dropped_views, dropped_values)
2450    }
2451}
2452
2453enum Subscription {
2454    FromModel {
2455        model_id: usize,
2456        callback: Box<dyn FnMut(&mut dyn Any, &dyn Any, &mut MutableAppContext, usize)>,
2457    },
2458    FromView {
2459        window_id: usize,
2460        view_id: usize,
2461        callback: Box<dyn FnMut(&mut dyn Any, &dyn Any, &mut MutableAppContext, usize, usize)>,
2462    },
2463}
2464
2465enum Observation {
2466    FromModel {
2467        model_id: usize,
2468        callback: Box<dyn FnMut(&mut dyn Any, usize, &mut MutableAppContext, usize)>,
2469    },
2470    FromView {
2471        window_id: usize,
2472        view_id: usize,
2473        callback: Box<dyn FnMut(&mut dyn Any, usize, &mut MutableAppContext, usize, usize)>,
2474    },
2475}
2476
2477type FutureHandler = Box<dyn FnOnce(Box<dyn Any>, &mut MutableAppContext) -> Box<dyn Any>>;
2478
2479struct StreamHandler {
2480    item_callback: Box<dyn FnMut(Box<dyn Any>, &mut MutableAppContext) -> bool>,
2481    done_callback: Box<dyn FnOnce(&mut MutableAppContext) -> Box<dyn Any>>,
2482}
2483
2484#[must_use]
2485pub struct EntityTask<T> {
2486    id: usize,
2487    task: Option<executor::Task<T>>,
2488    handler_map: TaskHandlerMap,
2489}
2490
2491enum TaskHandlerMap {
2492    Detached,
2493    Future(Rc<RefCell<HashMap<usize, FutureHandler>>>),
2494    Stream(Rc<RefCell<HashMap<usize, StreamHandler>>>),
2495}
2496
2497impl<T> EntityTask<T> {
2498    fn new(id: usize, task: executor::Task<T>, handler_map: TaskHandlerMap) -> Self {
2499        Self {
2500            id,
2501            task: Some(task),
2502            handler_map,
2503        }
2504    }
2505
2506    pub fn detach(mut self) {
2507        self.handler_map = TaskHandlerMap::Detached;
2508        self.task.take().unwrap().detach();
2509    }
2510
2511    pub async fn cancel(mut self) -> Option<T> {
2512        let task = self.task.take().unwrap();
2513        task.cancel().await
2514    }
2515}
2516
2517impl<T> Future for EntityTask<T> {
2518    type Output = T;
2519
2520    fn poll(
2521        self: std::pin::Pin<&mut Self>,
2522        ctx: &mut std::task::Context<'_>,
2523    ) -> std::task::Poll<Self::Output> {
2524        let task = unsafe { self.map_unchecked_mut(|task| task.task.as_mut().unwrap()) };
2525        task.poll(ctx)
2526    }
2527}
2528
2529impl<T> Drop for EntityTask<T> {
2530    fn drop(self: &mut Self) {
2531        match &self.handler_map {
2532            TaskHandlerMap::Detached => {
2533                return;
2534            }
2535            TaskHandlerMap::Future(map) => {
2536                map.borrow_mut().remove(&self.id);
2537            }
2538            TaskHandlerMap::Stream(map) => {
2539                map.borrow_mut().remove(&self.id);
2540            }
2541        }
2542    }
2543}
2544
2545#[cfg(test)]
2546mod tests {
2547    use super::*;
2548    use crate::elements::*;
2549    use smol::future::poll_once;
2550
2551    #[test]
2552    fn test_model_handles() {
2553        struct Model {
2554            other: Option<ModelHandle<Model>>,
2555            events: Vec<String>,
2556        }
2557
2558        impl Entity for Model {
2559            type Event = usize;
2560        }
2561
2562        impl Model {
2563            fn new(other: Option<ModelHandle<Self>>, ctx: &mut ModelContext<Self>) -> Self {
2564                if let Some(other) = other.as_ref() {
2565                    ctx.observe(other, |me, _, _| {
2566                        me.events.push("notified".into());
2567                    });
2568                    ctx.subscribe(other, |me, event, _| {
2569                        me.events.push(format!("observed event {}", event));
2570                    });
2571                }
2572
2573                Self {
2574                    other,
2575                    events: Vec::new(),
2576                }
2577            }
2578        }
2579
2580        App::test((), |app| {
2581            let handle_1 = app.add_model(|ctx| Model::new(None, ctx));
2582            let handle_2 = app.add_model(|ctx| Model::new(Some(handle_1.clone()), ctx));
2583            assert_eq!(app.ctx.models.len(), 2);
2584
2585            handle_1.update(app, |model, ctx| {
2586                model.events.push("updated".into());
2587                ctx.emit(1);
2588                ctx.notify();
2589                ctx.emit(2);
2590            });
2591            assert_eq!(handle_1.read(app).events, vec!["updated".to_string()]);
2592            assert_eq!(
2593                handle_2.read(app).events,
2594                vec![
2595                    "observed event 1".to_string(),
2596                    "notified".to_string(),
2597                    "observed event 2".to_string(),
2598                ]
2599            );
2600
2601            handle_2.update(app, |model, _| {
2602                drop(handle_1);
2603                model.other.take();
2604            });
2605
2606            assert_eq!(app.ctx.models.len(), 1);
2607            assert!(app.subscriptions.is_empty());
2608            assert!(app.observations.is_empty());
2609        });
2610    }
2611
2612    #[test]
2613    fn test_subscribe_and_emit_from_model() {
2614        #[derive(Default)]
2615        struct Model {
2616            events: Vec<usize>,
2617        }
2618
2619        impl Entity for Model {
2620            type Event = usize;
2621        }
2622
2623        App::test((), |app| {
2624            let handle_1 = app.add_model(|_| Model::default());
2625            let handle_2 = app.add_model(|_| Model::default());
2626            let handle_2b = handle_2.clone();
2627
2628            handle_1.update(app, |_, c| {
2629                c.subscribe(&handle_2, move |model: &mut Model, event, c| {
2630                    model.events.push(*event);
2631
2632                    c.subscribe(&handle_2b, |model, event, _| {
2633                        model.events.push(*event * 2);
2634                    });
2635                });
2636            });
2637
2638            handle_2.update(app, |_, c| c.emit(7));
2639            assert_eq!(handle_1.read(app).events, vec![7]);
2640
2641            handle_2.update(app, |_, c| c.emit(5));
2642            assert_eq!(handle_1.read(app).events, vec![7, 10, 5]);
2643        })
2644    }
2645
2646    #[test]
2647    fn test_observe_and_notify_from_model() {
2648        #[derive(Default)]
2649        struct Model {
2650            count: usize,
2651            events: Vec<usize>,
2652        }
2653
2654        impl Entity for Model {
2655            type Event = ();
2656        }
2657
2658        App::test((), |app| {
2659            let handle_1 = app.add_model(|_| Model::default());
2660            let handle_2 = app.add_model(|_| Model::default());
2661            let handle_2b = handle_2.clone();
2662
2663            handle_1.update(app, |_, c| {
2664                c.observe(&handle_2, move |model, observed, c| {
2665                    model.events.push(observed.read(c).count);
2666                    c.observe(&handle_2b, |model, observed, c| {
2667                        model.events.push(observed.read(c).count * 2);
2668                    });
2669                });
2670            });
2671
2672            handle_2.update(app, |model, c| {
2673                model.count = 7;
2674                c.notify()
2675            });
2676            assert_eq!(handle_1.read(app).events, vec![7]);
2677
2678            handle_2.update(app, |model, c| {
2679                model.count = 5;
2680                c.notify()
2681            });
2682            assert_eq!(handle_1.read(app).events, vec![7, 10, 5])
2683        })
2684    }
2685
2686    #[test]
2687    fn test_spawn_from_model() {
2688        #[derive(Default)]
2689        struct Model {
2690            count: usize,
2691        }
2692
2693        impl Entity for Model {
2694            type Event = ();
2695        }
2696
2697        App::test_async((), |mut app| async move {
2698            let handle = app.add_model(|_| Model::default());
2699            handle
2700                .update(&mut app, |_, c| {
2701                    c.spawn(async { 7 }, |model, output, _| {
2702                        model.count = output;
2703                    })
2704                })
2705                .await;
2706            app.read(|ctx| assert_eq!(handle.read(ctx).count, 7));
2707
2708            handle
2709                .update(&mut app, |_, c| {
2710                    c.spawn(async { 14 }, |model, output, _| {
2711                        model.count = output;
2712                    })
2713                })
2714                .await;
2715            app.read(|ctx| assert_eq!(handle.read(ctx).count, 14));
2716        });
2717    }
2718
2719    #[test]
2720    fn test_spawn_stream_local_from_model() {
2721        #[derive(Default)]
2722        struct Model {
2723            events: Vec<Option<usize>>,
2724        }
2725
2726        impl Entity for Model {
2727            type Event = ();
2728        }
2729
2730        App::test_async((), |mut app| async move {
2731            let handle = app.add_model(|_| Model::default());
2732            handle
2733                .update(&mut app, |_, c| {
2734                    c.spawn_stream(
2735                        smol::stream::iter(vec![1, 2, 3]),
2736                        |model, output, _| {
2737                            model.events.push(Some(output));
2738                        },
2739                        |model, _| {
2740                            model.events.push(None);
2741                        },
2742                    )
2743                })
2744                .await;
2745            app.read(|ctx| assert_eq!(handle.read(ctx).events, [Some(1), Some(2), Some(3), None]));
2746        })
2747    }
2748
2749    #[test]
2750    fn test_view_handles() {
2751        struct View {
2752            other: Option<ViewHandle<View>>,
2753            events: Vec<String>,
2754        }
2755
2756        impl Entity for View {
2757            type Event = usize;
2758        }
2759
2760        impl super::View for View {
2761            fn render<'a>(&self, _: &AppContext) -> ElementBox {
2762                Empty::new().boxed()
2763            }
2764
2765            fn ui_name() -> &'static str {
2766                "View"
2767            }
2768        }
2769
2770        impl View {
2771            fn new(other: Option<ViewHandle<View>>, ctx: &mut ViewContext<Self>) -> Self {
2772                if let Some(other) = other.as_ref() {
2773                    ctx.subscribe_to_view(other, |me, _, event, _| {
2774                        me.events.push(format!("observed event {}", event));
2775                    });
2776                }
2777                Self {
2778                    other,
2779                    events: Vec::new(),
2780                }
2781            }
2782        }
2783
2784        App::test((), |app| {
2785            let (window_id, _) = app.add_window(|ctx| View::new(None, ctx));
2786            let handle_1 = app.add_view(window_id, |ctx| View::new(None, ctx));
2787            let handle_2 = app.add_view(window_id, |ctx| View::new(Some(handle_1.clone()), ctx));
2788            assert_eq!(app.ctx.windows[&window_id].views.len(), 3);
2789
2790            handle_1.update(app, |view, ctx| {
2791                view.events.push("updated".into());
2792                ctx.emit(1);
2793                ctx.emit(2);
2794            });
2795            assert_eq!(handle_1.read(app).events, vec!["updated".to_string()]);
2796            assert_eq!(
2797                handle_2.read(app).events,
2798                vec![
2799                    "observed event 1".to_string(),
2800                    "observed event 2".to_string(),
2801                ]
2802            );
2803
2804            handle_2.update(app, |view, _| {
2805                drop(handle_1);
2806                view.other.take();
2807            });
2808
2809            assert_eq!(app.ctx.windows[&window_id].views.len(), 2);
2810            assert!(app.subscriptions.is_empty());
2811            assert!(app.observations.is_empty());
2812        })
2813    }
2814
2815    #[test]
2816    fn test_subscribe_and_emit_from_view() {
2817        #[derive(Default)]
2818        struct View {
2819            events: Vec<usize>,
2820        }
2821
2822        impl Entity for View {
2823            type Event = usize;
2824        }
2825
2826        impl super::View for View {
2827            fn render<'a>(&self, _: &AppContext) -> ElementBox {
2828                Empty::new().boxed()
2829            }
2830
2831            fn ui_name() -> &'static str {
2832                "View"
2833            }
2834        }
2835
2836        struct Model;
2837
2838        impl Entity for Model {
2839            type Event = usize;
2840        }
2841
2842        App::test((), |app| {
2843            let (window_id, handle_1) = app.add_window(|_| View::default());
2844            let handle_2 = app.add_view(window_id, |_| View::default());
2845            let handle_2b = handle_2.clone();
2846            let handle_3 = app.add_model(|_| Model);
2847
2848            handle_1.update(app, |_, c| {
2849                c.subscribe_to_view(&handle_2, move |me, _, event, c| {
2850                    me.events.push(*event);
2851
2852                    c.subscribe_to_view(&handle_2b, |me, _, event, _| {
2853                        me.events.push(*event * 2);
2854                    });
2855                });
2856
2857                c.subscribe_to_model(&handle_3, |me, _, event, _| {
2858                    me.events.push(*event);
2859                })
2860            });
2861
2862            handle_2.update(app, |_, c| c.emit(7));
2863            assert_eq!(handle_1.read(app).events, vec![7]);
2864
2865            handle_2.update(app, |_, c| c.emit(5));
2866            assert_eq!(handle_1.read(app).events, vec![7, 10, 5]);
2867
2868            handle_3.update(app, |_, c| c.emit(9));
2869            assert_eq!(handle_1.read(app).events, vec![7, 10, 5, 9]);
2870        })
2871    }
2872
2873    #[test]
2874    fn test_dropping_subscribers() {
2875        struct View;
2876
2877        impl Entity for View {
2878            type Event = ();
2879        }
2880
2881        impl super::View for View {
2882            fn render<'a>(&self, _: &AppContext) -> ElementBox {
2883                Empty::new().boxed()
2884            }
2885
2886            fn ui_name() -> &'static str {
2887                "View"
2888            }
2889        }
2890
2891        struct Model;
2892
2893        impl Entity for Model {
2894            type Event = ();
2895        }
2896
2897        App::test((), |app| {
2898            let (window_id, _) = app.add_window(|_| View);
2899            let observing_view = app.add_view(window_id, |_| View);
2900            let emitting_view = app.add_view(window_id, |_| View);
2901            let observing_model = app.add_model(|_| Model);
2902            let observed_model = app.add_model(|_| Model);
2903
2904            observing_view.update(app, |_, ctx| {
2905                ctx.subscribe_to_view(&emitting_view, |_, _, _, _| {});
2906                ctx.subscribe_to_model(&observed_model, |_, _, _, _| {});
2907            });
2908            observing_model.update(app, |_, ctx| {
2909                ctx.subscribe(&observed_model, |_, _, _| {});
2910            });
2911
2912            app.update(|| {
2913                drop(observing_view);
2914                drop(observing_model);
2915            });
2916
2917            emitting_view.update(app, |_, ctx| ctx.emit(()));
2918            observed_model.update(app, |_, ctx| ctx.emit(()));
2919        })
2920    }
2921
2922    #[test]
2923    fn test_observe_and_notify_from_view() {
2924        #[derive(Default)]
2925        struct View {
2926            events: Vec<usize>,
2927        }
2928
2929        impl Entity for View {
2930            type Event = usize;
2931        }
2932
2933        impl super::View for View {
2934            fn render<'a>(&self, _: &AppContext) -> ElementBox {
2935                Empty::new().boxed()
2936            }
2937
2938            fn ui_name() -> &'static str {
2939                "View"
2940            }
2941        }
2942
2943        #[derive(Default)]
2944        struct Model {
2945            count: usize,
2946        }
2947
2948        impl Entity for Model {
2949            type Event = ();
2950        }
2951
2952        App::test((), |app| {
2953            let (_, view) = app.add_window(|_| View::default());
2954            let model = app.add_model(|_| Model::default());
2955
2956            view.update(app, |_, c| {
2957                c.observe(&model, |me, observed, c| {
2958                    me.events.push(observed.read(c).count)
2959                });
2960            });
2961
2962            model.update(app, |model, c| {
2963                model.count = 11;
2964                c.notify();
2965            });
2966            assert_eq!(view.read(app).events, vec![11]);
2967        })
2968    }
2969
2970    #[test]
2971    fn test_dropping_observers() {
2972        struct View;
2973
2974        impl Entity for View {
2975            type Event = ();
2976        }
2977
2978        impl super::View for View {
2979            fn render<'a>(&self, _: &AppContext) -> ElementBox {
2980                Empty::new().boxed()
2981            }
2982
2983            fn ui_name() -> &'static str {
2984                "View"
2985            }
2986        }
2987
2988        struct Model;
2989
2990        impl Entity for Model {
2991            type Event = ();
2992        }
2993
2994        App::test((), |app| {
2995            let (window_id, _) = app.add_window(|_| View);
2996            let observing_view = app.add_view(window_id, |_| View);
2997            let observing_model = app.add_model(|_| Model);
2998            let observed_model = app.add_model(|_| Model);
2999
3000            observing_view.update(app, |_, ctx| {
3001                ctx.observe(&observed_model, |_, _, _| {});
3002            });
3003            observing_model.update(app, |_, ctx| {
3004                ctx.observe(&observed_model, |_, _, _| {});
3005            });
3006
3007            app.update(|| {
3008                drop(observing_view);
3009                drop(observing_model);
3010            });
3011
3012            observed_model.update(app, |_, ctx| ctx.notify());
3013        })
3014    }
3015
3016    #[test]
3017    fn test_focus() {
3018        #[derive(Default)]
3019        struct View {
3020            events: Vec<String>,
3021        }
3022
3023        impl Entity for View {
3024            type Event = String;
3025        }
3026
3027        impl super::View for View {
3028            fn render<'a>(&self, _: &AppContext) -> ElementBox {
3029                Empty::new().boxed()
3030            }
3031
3032            fn ui_name() -> &'static str {
3033                "View"
3034            }
3035
3036            fn on_focus(&mut self, ctx: &mut ViewContext<Self>) {
3037                self.events.push("self focused".into());
3038                ctx.emit("focused".into());
3039            }
3040
3041            fn on_blur(&mut self, ctx: &mut ViewContext<Self>) {
3042                self.events.push("self blurred".into());
3043                ctx.emit("blurred".into());
3044            }
3045        }
3046
3047        App::test((), |app| {
3048            let (window_id, view_1) = app.add_window(|_| View::default());
3049            let view_2 = app.add_view(window_id, |_| View::default());
3050
3051            view_1.update(app, |_, ctx| {
3052                ctx.subscribe_to_view(&view_2, |view_1, _, event, _| {
3053                    view_1.events.push(format!("view 2 {}", event));
3054                });
3055                ctx.focus(&view_2);
3056            });
3057
3058            view_1.update(app, |_, ctx| {
3059                ctx.focus(&view_1);
3060            });
3061
3062            assert_eq!(
3063                view_1.read(app).events,
3064                [
3065                    "self focused".to_string(),
3066                    "self blurred".to_string(),
3067                    "view 2 focused".to_string(),
3068                    "self focused".to_string(),
3069                    "view 2 blurred".to_string(),
3070                ],
3071            );
3072        })
3073    }
3074
3075    #[test]
3076    fn test_spawn_from_view() {
3077        #[derive(Default)]
3078        struct View {
3079            count: usize,
3080        }
3081
3082        impl Entity for View {
3083            type Event = ();
3084        }
3085
3086        impl super::View for View {
3087            fn render<'a>(&self, _: &AppContext) -> ElementBox {
3088                Empty::new().boxed()
3089            }
3090
3091            fn ui_name() -> &'static str {
3092                "View"
3093            }
3094        }
3095
3096        App::test_async((), |mut app| async move {
3097            let handle = app.add_window(|_| View::default()).1;
3098            handle
3099                .update(&mut app, |_, c| {
3100                    c.spawn(async { 7 }, |me, output, _| {
3101                        me.count = output;
3102                    })
3103                })
3104                .await;
3105            app.read(|ctx| assert_eq!(handle.read(ctx).count, 7));
3106            handle
3107                .update(&mut app, |_, c| {
3108                    c.spawn(async { 14 }, |me, output, _| {
3109                        me.count = output;
3110                    })
3111                })
3112                .await;
3113            app.read(|ctx| assert_eq!(handle.read(ctx).count, 14));
3114        });
3115    }
3116
3117    #[test]
3118    fn test_spawn_stream_local_from_view() {
3119        #[derive(Default)]
3120        struct View {
3121            events: Vec<Option<usize>>,
3122        }
3123
3124        impl Entity for View {
3125            type Event = ();
3126        }
3127
3128        impl super::View for View {
3129            fn render<'a>(&self, _: &AppContext) -> ElementBox {
3130                Empty::new().boxed()
3131            }
3132
3133            fn ui_name() -> &'static str {
3134                "View"
3135            }
3136        }
3137
3138        App::test_async((), |mut app| async move {
3139            let (_, handle) = app.add_window(|_| View::default());
3140            handle
3141                .update(&mut app, |_, c| {
3142                    c.spawn_stream(
3143                        smol::stream::iter(vec![1_usize, 2, 3]),
3144                        |me, output, _| {
3145                            me.events.push(Some(output));
3146                        },
3147                        |me, _| {
3148                            me.events.push(None);
3149                        },
3150                    )
3151                })
3152                .await;
3153
3154            app.read(|ctx| assert_eq!(handle.read(ctx).events, [Some(1), Some(2), Some(3), None]))
3155        });
3156    }
3157
3158    #[test]
3159    fn test_dispatch_action() {
3160        struct ViewA {
3161            id: usize,
3162        }
3163
3164        impl Entity for ViewA {
3165            type Event = ();
3166        }
3167
3168        impl View for ViewA {
3169            fn render<'a>(&self, _: &AppContext) -> ElementBox {
3170                Empty::new().boxed()
3171            }
3172
3173            fn ui_name() -> &'static str {
3174                "View"
3175            }
3176        }
3177
3178        struct ViewB {
3179            id: usize,
3180        }
3181
3182        impl Entity for ViewB {
3183            type Event = ();
3184        }
3185
3186        impl View for ViewB {
3187            fn render<'a>(&self, _: &AppContext) -> ElementBox {
3188                Empty::new().boxed()
3189            }
3190
3191            fn ui_name() -> &'static str {
3192                "View"
3193            }
3194        }
3195
3196        struct ActionArg {
3197            foo: String,
3198        }
3199
3200        App::test((), |app| {
3201            let actions = Rc::new(RefCell::new(Vec::new()));
3202
3203            let actions_clone = actions.clone();
3204            app.add_global_action("action", move |_: &ActionArg, _: &mut MutableAppContext| {
3205                actions_clone.borrow_mut().push("global a".to_string());
3206            });
3207
3208            let actions_clone = actions.clone();
3209            app.add_global_action("action", move |_: &ActionArg, _: &mut MutableAppContext| {
3210                actions_clone.borrow_mut().push("global b".to_string());
3211            });
3212
3213            let actions_clone = actions.clone();
3214            app.add_action("action", move |view: &mut ViewA, arg: &ActionArg, ctx| {
3215                assert_eq!(arg.foo, "bar");
3216                ctx.propagate_action();
3217                actions_clone.borrow_mut().push(format!("{} a", view.id));
3218            });
3219
3220            let actions_clone = actions.clone();
3221            app.add_action("action", move |view: &mut ViewA, _: &ActionArg, ctx| {
3222                if view.id != 1 {
3223                    ctx.propagate_action();
3224                }
3225                actions_clone.borrow_mut().push(format!("{} b", view.id));
3226            });
3227
3228            let actions_clone = actions.clone();
3229            app.add_action("action", move |view: &mut ViewB, _: &ActionArg, ctx| {
3230                ctx.propagate_action();
3231                actions_clone.borrow_mut().push(format!("{} c", view.id));
3232            });
3233
3234            let actions_clone = actions.clone();
3235            app.add_action("action", move |view: &mut ViewB, _: &ActionArg, ctx| {
3236                ctx.propagate_action();
3237                actions_clone.borrow_mut().push(format!("{} d", view.id));
3238            });
3239
3240            let (window_id, view_1) = app.add_window(|_| ViewA { id: 1 });
3241            let view_2 = app.add_view(window_id, |_| ViewB { id: 2 });
3242            let view_3 = app.add_view(window_id, |_| ViewA { id: 3 });
3243            let view_4 = app.add_view(window_id, |_| ViewB { id: 4 });
3244
3245            app.dispatch_action(
3246                window_id,
3247                vec![view_1.id(), view_2.id(), view_3.id(), view_4.id()],
3248                "action",
3249                ActionArg { foo: "bar".into() },
3250            );
3251
3252            assert_eq!(
3253                *actions.borrow(),
3254                vec!["4 d", "4 c", "3 b", "3 a", "2 d", "2 c", "1 b"]
3255            );
3256
3257            // Remove view_1, which doesn't propagate the action
3258            actions.borrow_mut().clear();
3259            app.dispatch_action(
3260                window_id,
3261                vec![view_2.id(), view_3.id(), view_4.id()],
3262                "action",
3263                ActionArg { foo: "bar".into() },
3264            );
3265
3266            assert_eq!(
3267                *actions.borrow(),
3268                vec!["4 d", "4 c", "3 b", "3 a", "2 d", "2 c", "global b", "global a"]
3269            );
3270        })
3271    }
3272
3273    #[test]
3274    fn test_dispatch_keystroke() {
3275        use std::cell::Cell;
3276
3277        #[derive(Clone)]
3278        struct ActionArg {
3279            key: String,
3280        }
3281
3282        struct View {
3283            id: usize,
3284            keymap_context: keymap::Context,
3285        }
3286
3287        impl Entity for View {
3288            type Event = ();
3289        }
3290
3291        impl super::View for View {
3292            fn render<'a>(&self, _: &AppContext) -> ElementBox {
3293                Empty::new().boxed()
3294            }
3295
3296            fn ui_name() -> &'static str {
3297                "View"
3298            }
3299
3300            fn keymap_context(&self, _: &AppContext) -> keymap::Context {
3301                self.keymap_context.clone()
3302            }
3303        }
3304
3305        impl View {
3306            fn new(id: usize) -> Self {
3307                View {
3308                    id,
3309                    keymap_context: keymap::Context::default(),
3310                }
3311            }
3312        }
3313
3314        App::test((), |app| {
3315            let mut view_1 = View::new(1);
3316            let mut view_2 = View::new(2);
3317            let mut view_3 = View::new(3);
3318            view_1.keymap_context.set.insert("a".into());
3319            view_2.keymap_context.set.insert("b".into());
3320            view_3.keymap_context.set.insert("c".into());
3321
3322            let (window_id, view_1) = app.add_window(|_| view_1);
3323            let view_2 = app.add_view(window_id, |_| view_2);
3324            let view_3 = app.add_view(window_id, |_| view_3);
3325
3326            // This keymap's only binding dispatches an action on view 2 because that view will have
3327            // "a" and "b" in its context, but not "c".
3328            let binding = keymap::Binding::new("a", "action", Some("a && b && !c"))
3329                .with_arg(ActionArg { key: "a".into() });
3330            app.add_bindings(vec![binding]);
3331
3332            let handled_action = Rc::new(Cell::new(false));
3333            let handled_action_clone = handled_action.clone();
3334            app.add_action("action", move |view: &mut View, arg: &ActionArg, _ctx| {
3335                handled_action_clone.set(true);
3336                assert_eq!(view.id, 2);
3337                assert_eq!(arg.key, "a");
3338            });
3339
3340            app.dispatch_keystroke(
3341                window_id,
3342                vec![view_1.id(), view_2.id(), view_3.id()],
3343                &Keystroke::parse("a").unwrap(),
3344            )
3345            .unwrap();
3346
3347            assert!(handled_action.get());
3348        });
3349    }
3350
3351    #[test]
3352    fn test_model_condition() {
3353        struct Counter(usize);
3354
3355        impl super::Entity for Counter {
3356            type Event = ();
3357        }
3358
3359        impl Counter {
3360            fn inc(&mut self, ctx: &mut ModelContext<Self>) {
3361                self.0 += 1;
3362                ctx.notify();
3363            }
3364        }
3365
3366        App::test_async((), |mut app| async move {
3367            let model = app.add_model(|_| Counter(0));
3368
3369            let condition1 = model.condition(&app, |model, _| model.0 == 2);
3370            let condition2 = model.condition(&app, |model, _| model.0 == 3);
3371            smol::pin!(condition1, condition2);
3372
3373            model.update(&mut app, |model, ctx| model.inc(ctx));
3374            assert_eq!(poll_once(&mut condition1).await, None);
3375            assert_eq!(poll_once(&mut condition2).await, None);
3376
3377            model.update(&mut app, |model, ctx| model.inc(ctx));
3378            assert_eq!(poll_once(&mut condition1).await, Some(()));
3379            assert_eq!(poll_once(&mut condition2).await, None);
3380
3381            model.update(&mut app, |model, ctx| model.inc(ctx));
3382            assert_eq!(poll_once(&mut condition2).await, Some(()));
3383
3384            // Broadcast channel should be removed if no conditions remain on next notification.
3385            model.update(&mut app, |_, ctx| ctx.notify());
3386            app.update(|ctx| assert!(ctx.async_observations.get(&model.id()).is_none()));
3387        });
3388    }
3389
3390    #[test]
3391    #[should_panic]
3392    fn test_model_condition_timeout() {
3393        struct Model;
3394
3395        impl super::Entity for Model {
3396            type Event = ();
3397        }
3398
3399        App::test_async((), |mut app| async move {
3400            let model = app.add_model(|_| Model);
3401            model.condition(&app, |_, _| false).await;
3402        });
3403    }
3404
3405    #[test]
3406    #[should_panic(expected = "model dropped with pending condition")]
3407    fn test_model_condition_panic_on_drop() {
3408        struct Model;
3409
3410        impl super::Entity for Model {
3411            type Event = ();
3412        }
3413
3414        App::test_async((), |mut app| async move {
3415            let model = app.add_model(|_| Model);
3416            let condition = model.condition(&app, |_, _| false);
3417            app.update(|_| drop(model));
3418            condition.await;
3419        });
3420    }
3421
3422    #[test]
3423    fn test_view_condition() {
3424        struct Counter(usize);
3425
3426        impl super::Entity for Counter {
3427            type Event = ();
3428        }
3429
3430        impl super::View for Counter {
3431            fn ui_name() -> &'static str {
3432                "test view"
3433            }
3434
3435            fn render(&self, _: &AppContext) -> ElementBox {
3436                Empty::new().boxed()
3437            }
3438        }
3439
3440        impl Counter {
3441            fn inc(&mut self, ctx: &mut ViewContext<Self>) {
3442                self.0 += 1;
3443                ctx.notify();
3444            }
3445        }
3446
3447        App::test_async((), |mut app| async move {
3448            let (_, view) = app.add_window(|_| Counter(0));
3449
3450            let condition1 = view.condition(&app, |view, _| view.0 == 2);
3451            let condition2 = view.condition(&app, |view, _| view.0 == 3);
3452            smol::pin!(condition1, condition2);
3453
3454            view.update(&mut app, |view, ctx| view.inc(ctx));
3455            assert_eq!(poll_once(&mut condition1).await, None);
3456            assert_eq!(poll_once(&mut condition2).await, None);
3457
3458            view.update(&mut app, |view, ctx| view.inc(ctx));
3459            assert_eq!(poll_once(&mut condition1).await, Some(()));
3460            assert_eq!(poll_once(&mut condition2).await, None);
3461
3462            view.update(&mut app, |view, ctx| view.inc(ctx));
3463            assert_eq!(poll_once(&mut condition2).await, Some(()));
3464
3465            // Broadcast channel should be removed if no conditions remain on next notification.
3466            view.update(&mut app, |_, ctx| ctx.notify());
3467            app.update(|ctx| assert!(ctx.async_observations.get(&view.id()).is_none()));
3468        });
3469    }
3470
3471    #[test]
3472    #[should_panic]
3473    fn test_view_condition_timeout() {
3474        struct View;
3475
3476        impl super::Entity for View {
3477            type Event = ();
3478        }
3479
3480        impl super::View for View {
3481            fn ui_name() -> &'static str {
3482                "test view"
3483            }
3484
3485            fn render(&self, _: &AppContext) -> ElementBox {
3486                Empty::new().boxed()
3487            }
3488        }
3489
3490        App::test_async((), |mut app| async move {
3491            let (_, view) = app.add_window(|_| View);
3492            view.condition(&app, |_, _| false).await;
3493        });
3494    }
3495
3496    #[test]
3497    #[should_panic(expected = "model dropped with pending condition")]
3498    fn test_view_condition_panic_on_drop() {
3499        struct View;
3500
3501        impl super::Entity for View {
3502            type Event = ();
3503        }
3504
3505        impl super::View for View {
3506            fn ui_name() -> &'static str {
3507                "test view"
3508            }
3509
3510            fn render(&self, _: &AppContext) -> ElementBox {
3511                Empty::new().boxed()
3512            }
3513        }
3514
3515        App::test_async((), |mut app| async move {
3516            let window_id = app.add_window(|_| View).0;
3517            let view = app.add_view(window_id, |_| View);
3518
3519            let condition = view.condition(&app, |_, _| false);
3520            app.update(|_| drop(view));
3521            condition.await;
3522        });
3523    }
3524
3525    // #[test]
3526    // fn test_ui_and_window_updates() {
3527    //     struct View {
3528    //         count: usize,
3529    //     }
3530
3531    //     impl Entity for View {
3532    //         type Event = ();
3533    //     }
3534
3535    //     impl super::View for View {
3536    //         fn render<'a>(&self, _: &AppContext) -> ElementBox {
3537    //             Empty::new().boxed()
3538    //         }
3539
3540    //         fn ui_name() -> &'static str {
3541    //             "View"
3542    //         }
3543    //     }
3544
3545    //     App::test(|app| async move {
3546    //         let (window_id, _) = app.add_window(|_| View { count: 3 });
3547    //         let view_1 = app.add_view(window_id, |_| View { count: 1 });
3548    //         let view_2 = app.add_view(window_id, |_| View { count: 2 });
3549
3550    //         // Ensure that registering for UI updates after mutating the app still gives us all the
3551    //         // updates.
3552    //         let ui_updates = Rc::new(RefCell::new(Vec::new()));
3553    //         let ui_updates_ = ui_updates.clone();
3554    //         app.on_ui_update(move |update, _| ui_updates_.borrow_mut().push(update));
3555
3556    //         assert_eq!(
3557    //             ui_updates.borrow_mut().drain(..).collect::<Vec<_>>(),
3558    //             vec![UiUpdate::OpenWindow {
3559    //                 window_id,
3560    //                 width: 1024.0,
3561    //                 height: 768.0,
3562    //             }]
3563    //         );
3564
3565    //         let window_invalidations = Rc::new(RefCell::new(Vec::new()));
3566    //         let window_invalidations_ = window_invalidations.clone();
3567    //         app.on_window_invalidated(window_id, move |update, _| {
3568    //             window_invalidations_.borrow_mut().push(update)
3569    //         });
3570
3571    //         let view_2_id = view_2.id();
3572    //         view_1.update(app, |view, ctx| {
3573    //             view.count = 7;
3574    //             ctx.notify();
3575    //             drop(view_2);
3576    //         });
3577
3578    //         let invalidation = window_invalidations.borrow_mut().drain(..).next().unwrap();
3579    //         assert_eq!(invalidation.updated.len(), 1);
3580    //         assert!(invalidation.updated.contains(&view_1.id()));
3581    //         assert_eq!(invalidation.removed, vec![view_2_id]);
3582
3583    //         let view_3 = view_1.update(app, |_, ctx| ctx.add_view(|_| View { count: 8 }));
3584
3585    //         let invalidation = window_invalidations.borrow_mut().drain(..).next().unwrap();
3586    //         assert_eq!(invalidation.updated.len(), 1);
3587    //         assert!(invalidation.updated.contains(&view_3.id()));
3588    //         assert!(invalidation.removed.is_empty());
3589
3590    //         view_3
3591    //             .update(app, |_, ctx| {
3592    //                 ctx.spawn_local(async { 9 }, |me, output, ctx| {
3593    //                     me.count = output;
3594    //                     ctx.notify();
3595    //                 })
3596    //             })
3597    //             .await;
3598
3599    //         let invalidation = window_invalidations.borrow_mut().drain(..).next().unwrap();
3600    //         assert_eq!(invalidation.updated.len(), 1);
3601    //         assert!(invalidation.updated.contains(&view_3.id()));
3602    //         assert!(invalidation.removed.is_empty());
3603    //     });
3604    // }
3605}