Added coordinate-based move validation

+ Simple input handler for testing purposes in BoardPanel
+ Abstract isValidMove method in Piece
+ Coordinate-based implementations of isValidMove in every subclass of
Piece

src/dev/kske/chess/Board.java

@@ -24,6 +24,15 @@ public class Board {
 		initializeDefaultPositions();
 	}
 
+	public boolean move(int xPos, int yPos, int xDest, int yDest) {
+		if (boardArr[xPos][yPos] == null || !boardArr[xPos][yPos].isValidMove(xPos, yPos, xDest, yDest)) return false;
+		else {
+			boardArr[xDest][yDest]	= boardArr[xPos][yPos];
+			boardArr[xPos][yPos]	= null;
+			return true;
+		}
+	}
+
 	/**
 	 * Initialized the board array with the default chess pieces and positions.
 	 */
@@ -62,7 +71,7 @@ public class Board {
 	}
 
 	/**
-	 * @return the board array
+	 * @return The board array
 	 */
 	public Piece[][] getBoardArr() { return boardArr; }
 }

src/dev/kske/chess/BoardPanel.java

@@ -5,8 +5,11 @@ import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.Image;
+import java.awt.Point;
 import java.awt.event.ComponentAdapter;
 import java.awt.event.ComponentEvent;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
 import java.io.File;
 import java.util.HashMap;
 import java.util.Map;
@@ -57,6 +60,23 @@ public class BoardPanel extends JPanel {
 				if (textures == null) loadPieceTextures();
 			}
 		});
+
+		// Add a mouse adapter for testing piece movement
+		addMouseListener(new MouseAdapter() {
+
+			private Point src;
+
+			@Override
+			public void mousePressed(MouseEvent evt) {
+				if (src == null) src = evt.getPoint();
+				else {
+					Point dest = evt.getPoint();
+					board.move(src.x / tileSize, src.y / tileSize, dest.x / tileSize, dest.y / tileSize);
+					repaint();
+					src = null;
+				}
+			}
+		});
 	}
 
 	@Override

src/dev/kske/chess/piece/Bishop.java

@@ -12,6 +12,11 @@ public class Bishop extends Piece {
 		super(color);
 	}
 
+	@Override
+	public boolean isValidMove(int xPos, int yPos, int xDest, int yDest) {
+		return Math.abs(xDest - xPos) == Math.abs(yDest - yPos);
+	}
+
 	@Override
 	public Type getType() { return Type.BISHOP; }
 }

src/dev/kske/chess/piece/King.java

@@ -12,6 +12,11 @@ public class King extends Piece {
 		super(color);
 	}
 
+	@Override
+	public boolean isValidMove(int xPos, int yPos, int xDest, int yDest) {
+		return Math.abs(xDest - xPos) <= 1 && Math.abs(yDest - yPos) <= 1;
+	}
+
 	@Override
 	public Type getType() { return Type.KING; }
 }

src/dev/kske/chess/piece/Knight.java

@@ -12,6 +12,13 @@ public class Knight extends Piece {
 		super(color);
 	}
 
+	@Override
+	public boolean isValidMove(int xPos, int yPos, int xDest, int yDest) {
+		int	xDist	= Math.abs(xDest - xPos);
+		int	yDist	= Math.abs(yDest - yPos);
+		return Math.abs(xDist - yDist) == 1 && xDist != 0 && yDist != 0;
+	}
+
 	@Override
 	public Type getType() { return Type.KNIGHT; }
 }

src/dev/kske/chess/piece/Pawn.java

@@ -12,6 +12,14 @@ public class Pawn extends Piece {
 		super(color);
 	}
 
+	@Override
+	public boolean isValidMove(int xPos, int yPos, int xDest, int yDest) {
+		int	direction	= color == Color.WHITE ? -1 : 1;
+		int	xDist		= Math.abs(xDest - xPos);
+		int	yDist		= (yDest - yPos) * direction;
+		return (xDist == 0 && yDist > 0 && yDist <= 2) || (xDist == 1 && yDist == 1);
+	}
+
 	@Override
 	public Type getType() { return Type.PAWN; }
 }

src/dev/kske/chess/piece/Piece.java

@@ -8,12 +8,14 @@ package dev.kske.chess.piece;
  */
 public abstract class Piece {
 
-	private Color color;
+	protected Color color;
 
 	public Piece(Color color) {
 		this.color = color;
 	}
 
+	public abstract boolean isValidMove(int xPos, int yPos, int xDest, int yDest);
+
 	public abstract Type getType();
 
 	public Color getColor() { return color; }

src/dev/kske/chess/piece/Queen.java

@@ -12,6 +12,11 @@ public class Queen extends Piece {
 		super(color);
 	}
 
+	@Override
+	public boolean isValidMove(int xPos, int yPos, int xDest, int yDest) {
+		return (xPos == xDest || yPos == yDest) || (Math.abs(xDest - xPos) == Math.abs(yDest - yPos));
+	}
+
 	@Override
 	public Type getType() { return Type.QUEEN; }
 }

src/dev/kske/chess/piece/Rook.java

@@ -12,6 +12,11 @@ public class Rook extends Piece {
 		super(color);
 	}
 
+	@Override
+	public boolean isValidMove(int xPos, int yPos, int xDest, int yDest) {
+		return xPos == xDest || yPos == yDest;
+	}
+
 	@Override
 	public Type getType() { return Type.ROOK; }
 }