Disappearing Problems Using a Released MouseEvent In Java

Question

Currently I have a game that I am building in Netbeans, and have been able to create a board, place the pieces and allow them to be moved anywhere using mouseveent's

But now I have ran into a problem when trying to code the pieces on the board to only do allowed actions.

The problem I am having is that every piece is still allowed to be moved but now when it is moved the selected piece disappears from the board completely ingorning all the new function in the mouse release event

The code I am trying to add is for the WhitePawn which is the only piece that should be allowed to move right now

The rest if they are tried to move should just return to there set positions regardless of where they are dragged. I have removed all code not relevant to the question and ran the debugger. From that I know a fact that the problem is somewhere in the mouse release event code, I just cant find it.

    public void mouseReleased(MouseEvent e) {
        if (chessPiece == null) {
            return;
        }

        chessPiece.setVisible(false);
        Boolean success = false;
        Component c = chessBoard.findComponentAt(e.getX(), e.getY());
        String tmp = chessPiece.getIcon().toString();
        String pieceName = tmp.substring(0, (tmp.length() - 4));
        Boolean validMove = false;

//Pawn Moves
//White Pawn
        if (pieceName.equals("WhitePawn")) {
            if (startY == 1) {
                if ((startX == (e.getX() / 75)) && ((((e.getY() / 75) - startY) == 1) || ((e.getY() / 75) - startY) == 2)) {
                    if ((((e.getY() / 75) - startY) == 2)) {
                        if ((!piecePresent(e.getX(), (e.getY()))) && (!piecePresent(e.getX(), (e.getY() + 75)))) {
                            validMove = true;
                        } else {
                            validMove = false;
                        }
                    } else {
                        if ((!piecePresent(e.getX(), (e.getY())))) {
                            validMove = true;
                        } else {
                            validMove = false;
                        }
                    }
                } else {
                    validMove = false;
                }
            } else {
                int newY = e.getY() / 75;
                int newX = e.getX() / 75;
                if ((startX - 1 >= 0) || (startX + 1 <= 7)) {
                    if ((piecePresent(e.getX(), (e.getY()))) && ((((newX == (startX + 1) && (startX + 1 <= 7))) || ((newX == (startX - 1)) && (startX - 1 >= 0))))) {
                        if (checkWhiteOponent(e.getX(), e.getY())) {
                            validMove = true;
                            if (startY == 6) {
                                success = true;
                            }
                        } else {
                            validMove = false;
                        }
                    } else {
                        if (!piecePresent(e.getX(), (e.getY()))) {
                            if ((startX == (e.getX() / 75)) && ((e.getY() / 75) - startY) == 1) {
                                if (startY == 6) {
                                    success = true;
                                }
                                validMove = true;
                            } else {
                                validMove = false;
                            }
                        } else {
                            validMove = false;
                        }
                    }
                } else {
                    validMove = false;
                }
            }
        }

        if (!validMove) {
            int location = 0;
            if (startY == 0) {
                location = startX;
            } else {
                location = (startY * 8) + startX;
            }
            String pieceLocation = pieceName + ".png";
            pieces = new JLabel(new ImageIcon(getClass().getResource(pieceLocation)));
            panels = (JPanel) chessBoard.getComponent(location);
            panels.add(pieces);
        } else {
            if (success) {
                int location = 56 + (e.getX() / 75);
                if (c instanceof JLabel) {
                    Container parent = c.getParent();
                    parent.remove(0);
                    pieces = new JLabel(new ImageIcon(getClass().getResource("WhiteQueen.png")));
                    parent = (JPanel) chessBoard.getComponent(location);
                    parent.add(pieces);
                } else {
                    Container parent = (Container) c;
                    pieces = new JLabel(new ImageIcon(getClass().getResource("WhiteQueen.png")));
                    parent = (JPanel) chessBoard.getComponent(location);
                    parent.add(pieces);
                }
            } else {
                if (c instanceof JLabel) {
                    Container parent = c.getParent();
                    parent.remove(0);
                    parent.add(chessPiece);
                } else {
                    Container parent = (Container) c;
                    parent.add(chessPiece);
                }
                chessPiece.setVisible(true);
            }
        }
    }

Image showing the folder layout of My build in case I have you can see somewhere that is not linked probably

Hopefully someone can see where I am going wrong, as I just want to get one piece moving before I split the pieces away from the board.java file completely into a new java file

Answer 1

I've looked through some of your code, again there's too much for me to go through in its entirety, but please let me give you some suggestions.

This is brittle/dangerous code:

    JLabel awaitingPiece = (JLabel) c1;
    String tmp1 = awaitingPiece.getIcon().toString();
    if (((tmp1.contains("White")))) {

You're using an object's toString() representation as part of your code logic which is something you should never do. You're also doing String manipulations on the String returned, and again using the returned String for code logic,

    Component c = chessBoard.findComponentAt(e.getX(), e.getY());
    String tmp = chessPiece.getIcon().toString();
    String pieceName = tmp.substring(0, (tmp.length() - 4));
    Boolean validMove = false;

again something that is dangerous to do.

Instead, you could get the Icon and compare for Icon equality via the equals(...) method. Even better though is to get your logic out of your GUI and into the Model section of your program. If you can fully separate concerns, you'll stand a much better chance of having smaller units of code that are much easier to debug for both you and for us.

Otherwise, to get a better more complete answer, you're still going to want to first work to isolate the error, and for that, I still recommend that you use an MCVE.

---

Also I see that you're checking if an Icon is named "WhitePawn"

    chessPiece.setVisible(false);
    Boolean success = false;
    Component c = chessBoard.findComponentAt(e.getX(), e.getY());
    String tmp = chessPiece.getIcon().toString();
    String pieceName = tmp.substring(0, (tmp.length() - 4));
    Boolean validMove = false;

    //Pawn Moves
    //White Pawn
    if (pieceName.equals("WhitePawn")) {

When in actuality I'll bet that it's named something quite differently. Since your Strings are playing a key role in your program (too great a role, I fear) are you debugging your String values to see why the code doesn't work?

For instance, a few println's could do wonders:

    chessPiece.setVisible(false);
    Boolean success = false;
    Component c = chessBoard.findComponentAt(e.getX(), e.getY());
    String tmp = chessPiece.getIcon().toString();
    String pieceName = tmp.substring(0, (tmp.length() - 4));

    System.out.println("pieceName is: " + pieceName); // ******* Added ********

    Boolean validMove = false;

Myself, I'd not use Strings for this but rather would use enums, something you know will be stable and will be exactly what you assume it to be.