samples/poppopwin: upgrade to first-class sample

samples/third_party/pop-pop-win/lib/src/html/game_manager.dart

-part of ppw_html;
-
-abstract class GameManager {
-  final int _width, _height, _bombCount;
-  final GameStorage _gameStorage = new GameStorage();
-
-  Game _game;
-  StreamSubscription _updatedEventId;
-  StreamSubscription _gameStateChangedId;
-  Timer _clockTimer;
-
-  GameManager(this._width, this._height, this._bombCount) {
-    newGame();
-  }
-
-  Game get game => _game;
-
-  Stream<EventArgs> get bestTimeUpdated => _gameStorage.bestTimeUpdated;
-
-  Future<int> get bestTimeMilliseconds =>
-      _gameStorage.getBestTimeMilliseconds(_width, _height, _bombCount);
-
-  void newGame() {
-    if(_updatedEventId != null) {
-      assert(_game != null);
-      assert(_gameStateChangedId != null);
-      _updatedEventId.cancel();
-      _gameStateChangedId.cancel();
-      _gameStateChanged(GameState.reset);
-    }
-    final f = new Field(_bombCount, _width, _height);
-    _game = new Game(f);
-    _updatedEventId = _game.updated.listen(gameUpdated);
-    _gameStateChangedId = _game.stateChanged.listen(_gameStateChanged);
-  }
-
-  void gameUpdated(args);
-
-  void resetScores() {
-    _gameStorage.reset();
-  }
-
-  void _click(int x, int y, bool alt) {
-    final ss = _game.getSquareState(x, y);
-
-    if(alt) {
-      if(ss == SquareState.hidden) {
-        _game.setFlag(x, y, true);
-      } else if(ss == SquareState.flagged) {
-        _game.setFlag(x, y, false);
-      } else if(ss == SquareState.revealed) {
-        _game.reveal(x, y);
-      }
-    } else {
-      if(ss == SquareState.hidden) {
-        _game.reveal(x, y);
-      }
-    }
-  }
-
-  void updateClock() {
-    if(_clockTimer == null && _game.state == GameState.started) {
-      _clockTimer = new Timer(const Duration(seconds: 1), updateClock);
-    } else if(_clockTimer != null && _game.state != GameState.started) {
-      _clockTimer.cancel();
-      _clockTimer = null;
-    }
-  }
-
-  void onNewBestTime(int value){}
-
-  void onGameStateChanged(GameState value){}
-
-  bool get _canClick {
-    return _game.state == GameState.reset ||
-        _game.state == GameState.started;
-  }
-
-  void _gameStateChanged(GameState newState) {
-    _gameStorage.recordState(newState);
-    if(newState == GameState.won) {
-      _gameStorage.updateBestTime(_game)
-        .then((bool newBestTime) {
-          if(newBestTime) {
-            bestTimeMilliseconds.then((int val) {
-              onNewBestTime(val);
-            });
-          }
-        });
-    }
-    updateClock();
-    onGameStateChanged(newState);
-  }
-}