Working on external engine integration, added extra menu

+ EngineUtil for storing engine information
- Changed all UCIListener methods to default

src/dev/kske/chess/uci/UCIListener.java

@@ -15,31 +15,31 @@ public interface UCIListener {
 	 * 
 	 * @param name The name of the engine
 	 */
-	void onIdName(String name);
+	default void onIdName(String name) {}
 
 	/**
 	 * Identifies the author of the engine.
 	 * 
 	 * @param author The name of the engine's author
 	 */
-	void onIdAuthor(String author);
+	default void onIdAuthor(String author) {}
 
 	/**
 	 * The engine is ready in UCI mode.
 	 */
-	void onUCIOk();
+	default void onUCIOk() {}
 
 	/**
 	 * The engine has processed all inputs and is ready for new commands.
 	 */
-	void onReadyOk();
+	default void onReadyOk() {}
 
 	/**
 	 * The engine has stopped searching and has found the best move.
 	 * 
 	 * @param move The best moves the engine has found
 	 */
-	void onBestMove(String move);
+	default void onBestMove(String move) {}
 
 	/**
 	 * The engine has stopped searching and has found the best move.
@@ -47,49 +47,48 @@ public interface UCIListener {
 	 * @param move       The best move the engine has found
 	 * @param ponderMove The move the engine likes to ponder on
 	 */
-	void onBestMove(String move, String ponderMove);
+	default void onBestMove(String move, String ponderMove) {}
 
 	/**
 	 * The engine will check the copy protection now.
 	 */
-	void onCopyProtectionChecking();
-
+	default void onCopyProtectionChecking() {}
 	/**
 	 * The engine has successfully checked the copy protection.
 	 */
-	void onCopyProtectionOk();
+	default void onCopyProtectionOk() {}
 
 	/**
 	 * The engine has encountered an error during copy protection checking.
 	 */
-	void onCopyProtectionError();
+	default void onCopyProtectionError() {}
 
 	/**
 	 * The engine will check the registration now.
 	 */
-	void onRegistrationChecking();
+	default void onRegistrationChecking() {}
 
 	/**
 	 * The engine has successfully checked the registration.
 	 */
-	void onRegistrationOk();
+	default void onRegistrationOk() {}
 
 	/**
 	 * The engine has encountered an error during registration checking.
 	 */
-	void onRegistrationError();
+	default void onRegistrationError() {}
 
 	/**
 	 * The engine sends information to the GUI.
 	 * 
 	 * @param additionalInfo Contains all pieces of information to be sent
 	 */
-	void onInfo(Map<String, String> additionalInfo);
+	default void onInfo(Map<String, String> additionalInfo) {}
 
 	/**
 	 * Tells the GUI which parameters can be changed in the engine.
 	 * 
 	 * @param option Option object describing the parameter
 	 */
-	void onOption(UCIOption option);
+	default void onOption(UCIOption option) {}
 }

src/dev/kske/chess/ui/EngineUtil.java

@@ -0,0 +1,61 @@
+package dev.kske.chess.ui;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import dev.kske.chess.uci.UCIHandle;
+import dev.kske.chess.uci.UCIListener;
+
+/**
+ * Project: <strong>Chess</strong><br>
+ * File: <strong>MenuBar.java</strong><br>
+ * Created: <strong>23.07.2019</strong><br>
+ * Author: <strong>Leon Hofmeister</strong>
+ */
+public class EngineUtil {
+
+	private static volatile List<EngineInfo> engineInfos;
+
+	static {
+		engineInfos = new ArrayList<>();
+	}
+
+	private EngineUtil() {}
+
+	public static void addEngine(String enginePath) {
+			try {
+				EngineInfo info = new EngineInfo(enginePath);
+				UCIHandle handle = new UCIHandle(enginePath);
+				handle.setListener(new UCIListener() {
+
+					@Override
+					public void onIdName(String name) {
+						info.name = name;
+					}
+
+					@Override
+					public void onIdAuthor(String author) {
+						info.author = author;
+					}
+					
+					@Override
+					public void onUCIOk() {
+						engineInfos.add(info);
+						System.out.println("Engine: " + info.name);
+					}
+				});
+				handle.start();
+			} catch (IOException ex) {
+				ex.printStackTrace();
+			}
+	}
+
+	public static class EngineInfo {
+		public String path, name, author;
+
+		public EngineInfo(String path) {
+			this.path = path;
+		}
+	}
+}

src/dev/kske/chess/ui/MenuBar.java

@@ -25,6 +25,7 @@ public class MenuBar extends JMenuBar {
 		boardPane = mainWindow.getBoardPane();
 
 		initGameMenu();
+		initEngineMenu();
 	}
 
 	private void initGameMenu() {
@@ -65,6 +66,24 @@ public class MenuBar extends JMenuBar {
 		naturalMenuItem.doClick();
 	}
 
+	private void initEngineMenu() {
+		JMenu engineMenu = new JMenu("Engine");
+		
+		JMenuItem addEngineMenuItem = new JMenuItem("Add engine");
+		
+		addEngineMenuItem.addActionListener((evt) -> {
+			String enginePath = JOptionPane.showInputDialog(getParent(),
+					"Enter the path to a UCI-compatible chess engine:", "Engine selection",
+					JOptionPane.QUESTION_MESSAGE);
+			if(enginePath != null)
+				EngineUtil.addEngine(enginePath);
+		});
+		
+		engineMenu.add(addEngineMenuItem);
+		
+		add(engineMenu);
+	}
+	
 	private void startGame(Game game) {
 		mainWindow.setGame(game);