JLabel Icon not showing after change

Question

I tried looking up this question, but most of the answers are that the file path is wrong, but that's most likely not the case. The file works the 1st time I use it.

I am making a battleships game, and use JLabels to show ships on map. I want to make a button to rotate ship from horizontal to vertical but it's icon disappears when I try to change it.

When I run this constructor code:

public Ship(int size, String direction, boolean active, Client c,
        ClientGUI cg) {
    this.c = c;
    this.cg = cg;
    health = size;
    this.active = active;
    this.direction = direction;

    file = "img/" + Integer.toString(health) + direction + ".png";   // String
    try {
        System.out.println(file);
        tx = ImageIO.read(new File(file));    // BufferedImage
    } catch (IOException e) {

        e.printStackTrace();
    }
    texture = new JLabel(new ImageIcon(tx));
    if (direction.equals("v"))
        texture.setBounds(0, 0, 40, 40 * size);
    else
        texture.setBounds(0, 0, 40 * size, 40);
    texture.setVisible(true);

}

everything works and I can see the image.

But then I try to rotate it, using pretty much the same code:

void rotate() {
    if (direction.equals("h")) {
        direction = "v";
        file = "img/" + Integer.toString(health) + direction + ".png";
        try {
            System.out.println(file);
            tx = ImageIO.read(new File(file));
        } catch (IOException e) {

            e.printStackTrace();
        }
        texture.setBounds(0,0,40, 40 * size);
        texture.setIcon(new ImageIcon(tx));

    } else {
        direction = "h";
        file = "img/" + Integer.toString(health) + direction + ".png";
        try {
            System.out.println(file);
            tx = ImageIO.read(new File(file));
        } catch (IOException e) {

            e.printStackTrace();
        }
        texture.setIcon(new ImageIcon(tx));
        texture.setBounds(0,0,40 * size, 40);
    }

    cg.repaint();    // not sure if I need to do this
}

and it disappears...

I tried placing two ships, one is rotated, it's just missing the JLabel or the icon on JLabel.

Answer 1

If you update the JLabel texture by calling a method which changes it's state, it may or may not be updated immediately unless you call texture.repaint() or texture.paintAll(texture.getGraphics()) , or some similar method.

Also, I would look into using a LayoutManager for whatever upper level component you are using to hold your grid of JLabels. If you use a GridLayout of your game board and either:

1. set the JLabel's preferred size with texture.setPreferredSize(Dimension) and call frame.pack() once when setting up your game; or

2. set the JLabel's size with label.setSize(Dimension) once and don't pack your JFrame

You will only need to set the size of the JLabel once, not every time you set a new ImageIcon to the label. Because, Ideally your game shouldn't be doing any extra work that it doesn't have to so it performs faster.

I would also recommend maintaining every possible ImageIcon as static fields in your class, rather than accessing them from the file every time. That way, you read them once from a static initializing method, which then reach ship can directly access when changing the direction.

Answer 2

I want to make a button to rotate ship from horizontal to vertical

You can use the Rotated Icon class to do the rotation for you.