Java Set JPanel Height To Percentage Of Window Height

Question

I've been trying to set a jpanel's height to 80% of the window's height. Every way I do it creates either a small rectangle, or fills the whole window. Currently, this is my code;

Toolkit tk = Toolkit.getDefaultToolkit();  
int xSize = ((int) tk.getScreenSize().getWidth());  
int ySize = ((int) tk.getScreenSize().getHeight());  
window.setSize(xSize,ySize);
JPanel p = new JPanel();
p.setBackground(Color.PINK);
p.setLayout(new BorderLayout());
int gameHeight = (int)(Math.round(ySize * 100.0/window.getHeight()));
int gameWidth = (int)(Math.round(xSize * 100.0/window.getWidth()));
p.setPreferredSize(new Dimension(gameHeight, gameWidth));
p.add(new JLabel(" "));
window.add(p, BorderLayout.SOUTH);

Answer 1

Your math is slightly off.

To acquire 80% of a value, you should multiple it by 0.80 , so you would want the panel height to be ySize * 0.80 and the panel width to be xSize * 0.80 .

int gameHeight = (int) (Math.round(ySize * 0.80));
int gameWidth = (int) (Math.round(xSize * 0.80));
p.setPreferredSize(new Dimension(gameWidth, gameHeight));