JLabel does not fully allign with JFrame

Question

I have a JFrame with a JLabel on top called "coloredLabel", an instance of the class it's in is running on both of them. a random amount of objects move around on the frame and label and don't directly interact with them. The only problem is that there is a bit of the frame visable above the label, what I want is that the label fully alligns with the frame, without pasting over the objects (which are painted in with an override paint method and mentioned as "game.newBall" and "game.moveBall". "test" is the name of the class. Here is how my main thread looks, the frame and the label are declared within it:

public static void main(String[] args) throws InterruptedException {
    JFrame frame = new JFrame("Bounce 2.0");
    JLabel coloredLabel = new JLabel("");
    test game = new test();
    frame.add(game);
    frame.setSize(300, 400);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    coloredLabel.setOpaque(true);
    coloredLabel.setBackground(game.backgroundColor);
    coloredLabel.setPreferredSize(new Dimension(1000000,1000000));
    frame.getContentPane().add(coloredLabel,BorderLayout.LINE_START);
    game.add(coloredLabel);

    for(int a = randInt(0,9); a<10; a++)
        game.newBall(randInt(0,300),randInt(0,400));

    while (true) {
        double height = frame.getContentPane().getSize().getHeight();
        double width = frame.getContentPane().getSize().getWidth();
        int n = 0;
        while(game.exists(n)==true){
            game.moveBall(n,width,height);
            n++;
        }
        game.repaint();
        Thread.sleep(10);
    }
}

So my question is: How do I allign the JLabel with the JFrame? so there is no space in between the JLabel and the frame.

I searched for this on this site, but couldn't find the same problem or something similar enough so I could fix this.

• solved - game.setBackground(...);

Answer 1

The only problem is that there is a bit of the frame visable above the label,

game.add(coloredLabel);

I'm guessing "game" is a JPanel. By default a JPanel uses a FlowLayout and by default the FlowLayout has horizontal and vertical gaps of 5 pixels.

Get rid of the gap in the FlowLayout. Read the API for the constructors/methods of the FlowLayout to customize its behaviour.

But of course the bigger issue is the design of your app. I don't understand your point of using the label and attempting to take up all the space of the frame. Just set the background of the game panel by using:

game.setBackground(...);

Also class names should:

1. start with an upper case character and
2. be descriptive.

"test" is neither.