src/dev/kske/chess/board/Board.java

@@ -63,13 +63,6 @@ public class Board {
 	 */
 	public Board() { initDefaultPositions(); }
 
-	/**
-	 * Initializes the board with data from a FEN-string.
-	 * 
-	 * @param fen The FEN-string to initialize the board from
-	 */
-	public Board(String fen) { initFromFEN(fen); }
-
 	/**
 	 * Creates a copy of another {@link Board} instance.<br>
 	 * The created object is a deep copy, but does not contain any move history
@@ -416,138 +409,6 @@ public class Board {
 		log.reset();
 	}
 
-	/**
-	 * Initialized the board with a position specified in a FEN-encoded string.
-	 * 
-	 * @param fen The FEN-encoded string representing target state of the board
-	 */
-	public void initFromFEN(String fen) {
-		String[] parts = fen.split(" ");
-		log.reset();
-
-		// Piece placement (from white's perspective)
-		String[] rows = parts[0].split("/");
-		for (int i = 0; i < 8; i++) {
-			char[] places = rows[i].toCharArray();
-			for (int j = 0, k = 0; k < places.length; j++, k++) {
-				if (Character.isDigit(places[k])) {
-					for (int l = j; l < Character.digit(places[k], 10); l++, j++)
-						boardArr[j][i] = null;
-					--j;
-				} else {
-					Color color = Character.isUpperCase(places[k]) ? Color.WHITE : Color.BLACK;
-					switch (Character.toLowerCase(places[k])) {
-						case 'k':
-							boardArr[j][i] = new King(color, this);
-							kingPos.put(color, new Position(j, i));
-							break;
-						case 'q':
-							boardArr[j][i] = new Queen(color, this);
-							break;
-						case 'r':
-							boardArr[j][i] = new Rook(color, this);
-							break;
-						case 'n':
-							boardArr[j][i] = new Knight(color, this);
-							break;
-						case 'b':
-							boardArr[j][i] = new Bishop(color, this);
-							break;
-						case 'p':
-							boardArr[j][i] = new Pawn(color, this);
-							break;
-						default:
-							System.err.printf("Unknown character '%c' in board declaration of FEN string '%s'%n", places[k], fen);
-					}
-				}
-			}
-		}
-
-		// Active color
-		log.setActiveColor(Color.fromFirstChar(parts[1].charAt(0)));
-
-		// Castling rights
-		Map<Type, Boolean> whiteCastling = new HashMap<>(), blackCastling = new HashMap<>();
-		for (char c : parts[2].toCharArray())
-			switch (c) {
-				case 'K':
-					whiteCastling.put(Type.KING, true);
-				case 'Q':
-					whiteCastling.put(Type.QUEEN, true);
-				case 'k':
-					blackCastling.put(Type.KING, true);
-				case 'q':
-					blackCastling.put(Type.QUEEN, true);
-				case '-':
-					break;
-				default:
-					System.err.printf("Unknown character '%c' in castling rights declaration of FEN string '%s'", c, fen);
-			}
-		// castlingRights.put(Color.WHITE, whiteCastling);
-		// castlingRights.put(Color.BLACK, blackCastling);
-
-		// En passant availability
-		if (!parts[3].equals("-")) log.setEnPassant(Position.fromLAN(parts[3]));
-
-		// Halfmove clock
-		log.setHalfmoveClock(Integer.parseInt(parts[4]));
-
-		// Fullmove counter
-		log.setFullmoveNumber(Integer.parseInt(parts[5]));
-	}
-
-	/**
-	 * @return a FEN-encoded string representing the board
-	 */
-	public String toFEN() {
-		StringBuilder sb = new StringBuilder();
-
-		// Piece placement (from white's perspective)
-		for (int i = 0; i < 8; i++) {
-			int emptyCount = 0;
-			for (int j = 0; j < 8; j++) {
-				final Piece piece = boardArr[j][i];
-				if (piece == null) ++emptyCount;
-				else {
-					if (emptyCount != 0) {
-						sb.append(emptyCount);
-						emptyCount = 0;
-					}
-					char p = boardArr[j][i].getType().firstChar();
-					sb.append(piece.getColor() == Color.WHITE ? Character.toUpperCase(p) : p);
-				}
-			}
-			if (emptyCount != 0) sb.append(emptyCount);
-			if (i < 7) sb.append('/');
-		}
-
-		// Active color
-		sb.append(" " + log.getActiveColor().firstChar());
-
-		// Castling Rights
-		sb.append(' ');
-		StringBuilder castlingSb = new StringBuilder();
-		// if (castlingRights.get(Color.WHITE).get(Type.KING)) castlingSb.append('K');
-		// if (castlingRights.get(Color.WHITE).get(Type.QUEEN)) castlingSb.append('Q');
-		// if (castlingRights.get(Color.BLACK).get(Type.KING)) castlingSb.append('k');
-		// if (castlingRights.get(Color.BLACK).get(Type.QUEEN)) castlingSb.append('q');
-		if (castlingSb.length() == 0) sb.append("-");
-		sb.append(castlingSb);
-
-		final MoveNode lastMove = log.getLast();
-
-		// En passant availability
-		sb.append(" " + (lastMove == null || lastMove.enPassant == null ? "-" : lastMove.enPassant.toLAN()));
-
-		// Halfmove clock
-		sb.append(" " + String.valueOf(lastMove == null ? 0 : lastMove.halfmoveClock));
-
-		// Fullmove counter
-		sb.append(" " + String.valueOf(lastMove == null ? 1 : lastMove.fullmoveCounter));
-
-		return sb.toString();
-	}
-
 	@Override
 	public int hashCode() {
 		final int	prime	= 31;

src/dev/kske/chess/board/FENString.java

@@ -47,7 +47,7 @@ public class FENString {
 	public FENString(String fen) throws ChessException {
 		// Check fen string against regex
 		Pattern	fenPattern	= Pattern.compile(
-				"^(?<piecePlacement>(?:[1-8nbrqkpNBRQKP]{1,8}\\/){7}[1-8nbrqkpNBRQKP]{1,8}) (?<activeColor>[wb]) (?<castlingAvailability>-|[KQkq]{1,4}) (?<enPassantTargetSquare>-|[a-h][1-8]) (?<halfmoveClock>\\d) (?<fullmoveNumber>\\d)$");
+				"^(?<piecePlacement>(?:[1-8nbrqkpNBRQKP]{1,8}\\/){7}[1-8nbrqkpNBRQKP]{1,8}) (?<activeColor>[wb]) (?<castlingAvailability>-|[KQkq]{1,4}) (?<enPassantTargetSquare>-|[a-h][1-8]) (?<halfmoveClock>\\d+) (?<fullmoveNumber>\\d+)$");
 		Matcher	matcher		= fenPattern.matcher(fen);
 		if (!matcher.find()) throw new ChessException("FEN string does not match pattern " + fenPattern.pattern());
 
@@ -55,8 +55,7 @@ public class FENString {
 		piecePlacement			= matcher.group("piecePlacement");
 		activeColor				= Color.fromFirstChar(matcher.group("activeColor").charAt(0));
 		castlingAvailability	= matcher.group("castlingAvailability");
-		if (!matcher.group("enPassantTargetSquare").equals("-"))
+		if (!matcher.group("enPassantTargetSquare").equals("-")) enPassantTargetSquare = Position.fromLAN(matcher.group("enPassantTargetSquare"));
-			enPassantTargetSquare = Position.fromLAN(matcher.group("enPassantTargetSquare"));
 		halfmoveClock	= Integer.parseInt(matcher.group("halfmoveClock"));
 		fullmoveNumber	= Integer.parseInt(matcher.group("fullmoveNumber"));
 

src/dev/kske/chess/game/UCIPlayer.java

@@ -2,6 +2,7 @@ package dev.kske.chess.game;
 
 import java.io.IOException;
 
+import dev.kske.chess.board.FENString;
 import dev.kske.chess.board.Move;
 import dev.kske.chess.board.Piece.Color;
 import dev.kske.chess.uci.UCIHandle;
@@ -30,7 +31,7 @@ public class UCIPlayer extends Player implements UCIListener {
 
 	@Override
 	public void requestMove() {
-		handle.positionFEN(board.toFEN());
+		handle.positionFEN(new FENString(board).toString());
 		handle.go();
 	}
 

src/dev/kske/chess/pgn/PGNGame.java

@@ -7,6 +7,7 @@ import java.util.regex.MatchResult;
 import java.util.regex.Pattern;
 
 import dev.kske.chess.board.Board;
+import dev.kske.chess.board.FENString;
 import dev.kske.chess.exception.ChessException;
 
 /**
@@ -26,8 +27,7 @@ public class PGNGame {
 		MatchResult	matchResult;
 		Pattern		tagPairPattern	= Pattern.compile("\\[(\\w+) \"(.*)\"]"),
 				movePattern = Pattern.compile("\\d+\\.\\s+(?:(?:(\\S+)\\s+(\\S+))|(?:O-O-O)|(?:O-O))(?:\\+{0,2}|\\#)"),
-				nagPattern = Pattern.compile("(\\$\\d{1,3})*"),
+				nagPattern = Pattern.compile("(\\$\\d{1,3})*"), terminationMarkerPattern = Pattern.compile("1-0|0-1|1\\/2-1\\/2|\\*");
-				terminationMarkerPattern = Pattern.compile("1-0|0-1|1\\/2-1\\/2|\\*");
 
 		// Parse tag pairs
 		while (sc.findInLine(tagPairPattern) != null) {
@@ -48,30 +48,23 @@ public class PGNGame {
 				matchResult = sc.match();
 				if (matchResult.groupCount() > 0) for (int i = 1; i < matchResult.groupCount() + 1; i++) {
 					game.board.move(matchResult.group(i));
-					System.out.println(game.getBoard().getLog().getLast().move.toLAN() + ": " + game.board.toFEN());
+					System.out.println(game.getBoard().getLog().getLast().move.toLAN() + ": " + new FENString(game.board).toString());
 				}
 				else break;
 			} else break;
 		}
 
 		// Parse game termination marker
-		if (sc.findWithinHorizon(terminationMarkerPattern, 20) == null)
+		if (sc.findWithinHorizon(terminationMarkerPattern, 20) == null) System.err.println("Termination marker expected");
-			System.err.println("Termination marker expected");
 
 		return game;
 	}
 
-	public String getTag(String tagName) {
+	public String getTag(String tagName) { return tagPairs.get(tagName); }
-		return tagPairs.get(tagName);
-	}
 
-	public boolean hasTag(String tagName) {
+	public boolean hasTag(String tagName) { return tagPairs.containsKey(tagName); }
-		return tagPairs.containsKey(tagName);
-	}
 
-	public void setTag(String tagName, String tagValue) {
+	public void setTag(String tagName, String tagValue) { tagPairs.put(tagName, tagValue); }
-		tagPairs.put(tagName, tagValue);
-	}
 
 	public Board getBoard() { return board; }
 }

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

@@ -11,7 +11,10 @@ import java.io.FileReader;
 import java.io.IOException;
 import java.util.List;
 
-import dev.kske.chess.board.Board;
+import javax.swing.JOptionPane;
+
+import dev.kske.chess.board.FENString;
+import dev.kske.chess.exception.ChessException;
 import dev.kske.chess.game.Game;
 
 /**
@@ -24,9 +27,7 @@ public class FENDropTarget extends DropTargetAdapter {
 
 	private MainWindow mainWindow;
 
-	public FENDropTarget(MainWindow mainWindow) {
+	public FENDropTarget(MainWindow mainWindow) { this.mainWindow = mainWindow; }
-		this.mainWindow = mainWindow;
-	}
 
 	@SuppressWarnings("unchecked")
 	@Override
@@ -38,9 +39,18 @@ public class FENDropTarget extends DropTargetAdapter {
 					final GamePane	gamePane	= mainWindow.addGamePane();
 					final String	fen			= br.readLine();
 					DialogUtil.showGameConfigurationDialog(null, (whiteName, blackName) -> {
-						final Game game = new Game(gamePane.getBoardPane(), whiteName, blackName, new Board(fen));
+						Game game;
+						try {
+							game = new Game(gamePane.getBoardPane(), whiteName, blackName, new FENString(fen).getBoard());
 							gamePane.setGame(game);
 							game.start();
+						} catch (ChessException e) {
+							e.printStackTrace();
+							JOptionPane.showMessageDialog(mainWindow,
+									"Failed to load FEN string: " + e.toString(),
+									"FEN loading error",
+									JOptionPane.ERROR_MESSAGE);
+						}
 					});
 					evt.dropComplete(true);
 				} catch (IOException e) {

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

@@ -12,7 +12,8 @@ import javax.swing.JMenuBar;
 import javax.swing.JMenuItem;
 import javax.swing.JOptionPane;
 
-import dev.kske.chess.board.Board;
+import dev.kske.chess.board.FENString;
+import dev.kske.chess.exception.ChessException;
 import dev.kske.chess.game.Game;
 import dev.kske.chess.io.EngineUtil;
 import dev.kske.chess.pgn.PGNDatabase;
@@ -42,8 +43,7 @@ public class MenuBar extends JMenuBar {
 		JMenu gameMenu = new JMenu("Game");
 
 		JMenuItem newGameMenuItem = new JMenuItem("New Game");
-		newGameMenuItem
+		newGameMenuItem.addActionListener((evt) -> DialogUtil.showGameConfigurationDialog(mainWindow, (whiteName, blackName) -> {
-			.addActionListener((evt) -> DialogUtil.showGameConfigurationDialog(mainWindow, (whiteName, blackName) -> {
 			GamePane	gamePane	= mainWindow.addGamePane();
 			Game		game		= new Game(gamePane.getBoardPane(), whiteName, blackName);
 			gamePane.setGame(game);
@@ -64,10 +64,8 @@ public class MenuBar extends JMenuBar {
 
 		JMenuItem addEngineMenuItem = new JMenuItem("Add engine");
 		addEngineMenuItem.addActionListener((evt) -> {
-			String enginePath = JOptionPane.showInputDialog(getParent(),
+			String enginePath = JOptionPane
-					"Enter the path to a UCI-compatible chess engine:",
+				.showInputDialog(getParent(), "Enter the path to a UCI-compatible chess engine:", "Engine selection", JOptionPane.QUESTION_MESSAGE);
-					"Engine selection",
-					JOptionPane.QUESTION_MESSAGE);
 			if (enginePath != null) EngineUtil.addEngine(enginePath);
 		});
 
@@ -83,7 +81,7 @@ public class MenuBar extends JMenuBar {
 
 		JMenuItem exportFENMenuItem = new JMenuItem("Export board to FEN");
 		exportFENMenuItem.addActionListener((evt) -> {
-			final String fen = mainWindow.getSelectedGamePane().getGame().getBoard().toFEN();
+			final String fen = new FENString(mainWindow.getSelectedGamePane().getGame().getBoard()).toString();
 			Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection(fen), null);
 			JOptionPane.showMessageDialog(mainWindow, String.format("FEN-string copied to clipboard!%n%s", fen));
 		});
@@ -94,9 +92,16 @@ public class MenuBar extends JMenuBar {
 			final GamePane	gamePane	= mainWindow.addGamePane();
 			final String	fen			= JOptionPane.showInputDialog("Enter a FEN string: ");
 			DialogUtil.showGameConfigurationDialog(mainWindow, (whiteName, blackName) -> {
-				final Game game = new Game(gamePane.getBoardPane(), whiteName, blackName, new Board(fen));
+				Game game;
+				try {
+					game = new Game(gamePane.getBoardPane(), whiteName, blackName, new FENString(fen).getBoard());
 					gamePane.setGame(game);
 					game.start();
+				} catch (ChessException e) {
+					e.printStackTrace();
+					JOptionPane
+						.showMessageDialog(mainWindow, "Failed to load FEN string: " + e.toString(), "FEN loading error", JOptionPane.ERROR_MESSAGE);
+				}
 			});
 		});
 		toolsMenu.add(loadFromFENMenuItem);
@@ -113,9 +118,18 @@ public class MenuBar extends JMenuBar {
 					final GamePane	gamePane	= mainWindow.addGamePane(name);
 					final String	fen			= new String(Files.readAllBytes(file.toPath()), StandardCharsets.UTF_8);
 					DialogUtil.showGameConfigurationDialog(mainWindow, (whiteName, blackName) -> {
-						final Game game = new Game(gamePane.getBoardPane(), whiteName, blackName, new Board(fen));
+						Game game;
+						try {
+							game = new Game(gamePane.getBoardPane(), whiteName, blackName, new FENString(fen).getBoard());
 							gamePane.setGame(game);
 							game.start();
+						} catch (ChessException e) {
+							e.printStackTrace();
+							JOptionPane.showMessageDialog(mainWindow,
+									"Failed to load FEN string: " + e.toString(),
+									"FEN loading error",
+									JOptionPane.ERROR_MESSAGE);
+						}
 					});
 				} catch (Exception e) {
 					e.printStackTrace();
@@ -134,14 +148,10 @@ public class MenuBar extends JMenuBar {
 						String[] gameNames = new String[pgnDB.getGames().size()];
 						for (int i = 0; i < gameNames.length; i++) {
 							final PGNGame game = pgnDB.getGames().get(i);
-							gameNames[i] = String.format("%s vs %s: %s",
+							gameNames[i] = String.format("%s vs %s: %s", game.getTag("White"), game.getTag("Black"), game.getTag("Result"));
-									game.getTag("White"),
-									game.getTag("Black"),
-									game.getTag("Result"));
 						}
 						JComboBox<String> comboBox = new JComboBox<>(gameNames);
-						JOptionPane
+						JOptionPane.showInputDialog(mainWindow, comboBox, "Select a game", JOptionPane.QUESTION_MESSAGE);
-							.showInputDialog(mainWindow, comboBox, "Select a game", JOptionPane.QUESTION_MESSAGE);
 						DialogUtil.showGameConfigurationDialog(mainWindow, (whiteName, blackName) -> {
 							final Game game = new Game(gamePane.getBoardPane(), whiteName, blackName,
 									pgnDB.getGames().get(comboBox.getSelectedIndex()).getBoard());

test/dev/kske/chess/board/FENStringTest.java

@@ -35,7 +35,7 @@ class FENStringTest {
 	 */
 	@BeforeEach
 	void setUp() throws Exception {
-		fenStrings.addAll(Arrays.asList("rnbqkbnr/pp1ppppp/8/2p5/4P3/5N2/PPPP1PPP/RNBQKB1R b - - 1 2"));
+		fenStrings.addAll(Arrays.asList("rnbqkbnr/pp1ppppp/8/2p5/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 1 2"));
 		Board board = new Board();
 		board.set(Position.fromLAN("c7"), null);
 		board.set(Position.fromLAN("c5"), new Pawn(Color.BLACK, board));