first working version (but with limited interactivity)

BootsFacesChess/src/main/java/de/beyondjava/bootsfaces/chess/jsf/Board.java

@@ -5,27 +5,30 @@
 import java.util.List;
 
 import javax.faces.bean.ManagedBean;
-import javax.faces.bean.ViewScoped;
+import javax.faces.bean.SessionScoped;
 
+import de.beyondjava.bootsfaces.chess.Exceptions.EndOfGameException;
+import de.beyondjava.bootsfaces.chess.common.ChessConstants;
+import de.beyondjava.bootsfaces.chess.common.Move;
 import de.beyondjava.bootsfaces.chess.objectOrientedEngine.Chessboard;
 
 @ManagedBean
-@ViewScoped
+@SessionScoped
 public class Board implements Serializable {
 	private static final long serialVersionUID = 1L;
-	
+
 	private Chessboard chessboard = new Chessboard();
-	
-	private boolean isPieceSelected=false;
-	
+
+	private boolean isPieceSelected = false;
+
 	private int selectedPieceRow;
-	
+
 	private int selectedPieceColumn;
-	
+
 	private List<Row> rows;
-	
+
 	public Board() {
-		
+
 		redraw();
 	}
 
@@ -44,22 +47,49 @@ public List<Row> getRows() {
 	public void setRows(List<Row> rows) {
 		this.rows = rows;
 	}
-	
+
 	public String getOpacity(int row, int column) {
-		if (!isPieceSelected) return "1.0";
-		if (selectedPieceColumn==column && selectedPieceRow==row) return "1.0";
+		if (!isPieceSelected)
+			return "1.0";
+		if (selectedPieceColumn == column && selectedPieceRow == row)
+			return "1.0";
+		if (chessboard.isMovePossible(selectedPieceRow, selectedPieceColumn, row, column))
+			return "1.0";
 		return "0.7";
 	}
-	
+
 	public void onclick(int row, int column) {
 		if (isPieceSelected) {
-			isPieceSelected=false;
-		}
-		else
-		{
-			isPieceSelected=true;
-			selectedPieceRow=row;
-			selectedPieceColumn=column;
+			isPieceSelected = false;
+			if (chessboard.isMovePossible(selectedPieceRow, selectedPieceColumn, row, column)) {
+				// chessboard = chessboard.move(selectedPieceRow,
+				// selectedPieceColumn, row, column,
+				// fields, board, guiState, images, checkmate, whiteMoves,
+				// blackMoves);
+
+				chessboard = chessboard.moveChessPiece(selectedPieceRow, selectedPieceColumn, row, column,
+						ChessConstants.W_QUEEN);
+				selectedPieceRow=0;
+				selectedPieceColumn=0;
+				try {
+					Move move = chessboard.findBestMove();
+					chessboard = chessboard.moveChessPiece(move.fromRow, move.fromColumn, move.toRow, move.toColumn,
+							ChessConstants.W_QUEEN);
+				} catch (EndOfGameException e) {
+					// TODO Auto-generated catch block
+					e.printStackTrace();
+				}
+			}
+
+		} else {
+			int piece = chessboard.getChessPiece(row, column);
+			if (piece != ChessConstants.B_EMPTY && piece != ChessConstants.W_EMPTY) {
+				if (chessboard.isActivePlayersPiece(piece)) {
+					isPieceSelected = true;
+					selectedPieceRow = row;
+					selectedPieceColumn = column;
+				}
+			}
 		}
 		redraw();
 	}

BootsFacesChess/src/main/java/de/beyondjava/bootsfaces/chess/jsf/Row.java

@@ -11,7 +11,9 @@ public class Row implements Serializable {
 	public Row(int row, int[] pieces) {
 		int background = 1-row%2;
 		for (int col=0; col<pieces.length; col++) {
-			fileNames.add("wikimediaimages/" + ImageNames.chessPiecesFileName[pieces[col]+background]);
+			int piece = pieces[col];
+			if (piece<0) piece=0; // treat en-passant-fields as empty fields
+			fileNames.add("wikimediaimages/" + ImageNames.chessPiecesFileName[piece+background]);
 			background=1-background;
 		}
 	}

BootsFacesChess/src/main/java/de/beyondjava/bootsfaces/chess/objectOrientedEngine/ChessboardBasis.java

@@ -178,7 +178,7 @@ protected boolean isBlackPiece(int piece) {
         return (((piece / 2) % 2) == 1);
     }
 
-    protected boolean isActivePlayersPiece(int piece) {
+    public boolean isActivePlayersPiece(int piece) {
         return activePlayerIsWhite == isWhitePiece(piece);
     }