Question

This is my JFrame code:

public static int width = 800;
public static int height = 600;

public static void main(String[]args){
    JFrame frame= new JFrame("RETRO");
    frame.add(new Screen());

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(width,height);
    frame.setVisible(true);
    frame.setResizable(false);
}

Basically when I want something to move to the edge of the screen, I have to add extra pixels for it work (I’m guessing because it includes the frame itself instead of just the display size? However the origins work fine (x=0, y=0)). Example:

public double getX(){
    if(x<0)
        x=0;
    if(x+getImage().getWidth(null)>Game.width-6)
        x=Game.width-6-getImage().getWidth(null);
    return x;
}

public double getY(){
    if(y<0)
        y=0;
    if(y+getImage().getHeight(null)>Game.height-26)
        y=Game.height-26-getImage().getHeight(null);
    return y;
}

Is there a way around this? I don’t think the JFrame would be the same size on everyone’s computer, not to mention the guesswork. Rather have it much neater and flexible by using an exiting variable from the JFrame component. Does there exist something like a frame.getDisplayWidth and Height function?

Answer 1

• Don’t set the size of the frame, set the preferred size of the contents.
• Pack the frame
• Get co-ordinates according to the position in the content

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How do you set a ‘preferred size’ for the contents? I’m using a Screen class (extended JPanel) for rendering.

screen.setPreferredSize(new Dimension (600,400));
frame.setContentPane(screen);
frame.pack();
// frame will now be the size it needs to display the contents 
// and the frame's own decorations (title bar etc.)
// ..now add a nice tweak.
frame.setMinimumSize(frame.getSize());