check draw

app/src/main/java/chess/controller/CommandExecutor.java

@@ -59,7 +59,11 @@ public class CommandExecutor {
 	}
 
 	private void switchPlayerTurn() {
-		this.game.switchPlayerTurn();
+		if(this.game.switchPlayerTurn()) {
+			this.dispatcher.onDraw();
+			this.dispatcher.onGameEnd();
+			return;
+		}
 		this.dispatcher.onPlayerTurn(this.game.getPlayerTurn());
 	}
 

app/src/main/java/chess/controller/event/GameAdaptator.java

@@ -42,4 +42,7 @@ public abstract class GameAdaptator implements GameListener {
 	@Override
 	public void onMoveNotAllowed(Move move) {}
 
+	@Override
+	public void onDraw() {}
+
 }

app/src/main/java/chess/controller/event/GameDispatcher.java

@@ -10,7 +10,7 @@ import chess.model.Color;
 import chess.model.Coordinate;
 import chess.model.Move;
 
-public class GameDispatcher implements GameListener{
+public class GameDispatcher implements GameListener {
 
 	private final List<GameListener> listeners;
 	private final ExecutorService executor;
@@ -88,6 +88,11 @@ public class GameDispatcher implements GameListener{
 		asyncForEachCall((l) -> l.onMoveNotAllowed(move));
 	}
 
+	@Override
+	public void onDraw() {
+		asyncForEachCall((l) -> l.onDraw());
+	}
+
 	public void stopService() {
 		this.executor.shutdown();
 	}

app/src/main/java/chess/controller/event/GameListener.java

@@ -10,6 +10,11 @@ public interface GameListener {
 	 * Invoked when the display of the board should be updated
 	 */
 	void onBoardUpdate();
+
+	/**
+	 * Invoked when a draw occurs (same position is repeated three times)
+	 */
+	void onDraw();
 	
 	/**
 	 * Invoked when the game has ended (by a win or a draw)