Set the JPanel size to fill parent with little margin

Question

I have two Jpanel (JpanelLeft and JpanelLeftContent) how can i make the JpanelLeftContent fill parent size with a little margin on the lef

Answer 1

Do try this code example :

import java.awt.*;
import javax.swing.*;

public class InsetTesting extends JFrame
{
    private void createAndDisplayGUI()
    {
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        setLocationByPlatform(true);

        JPanel contentPane = new JPanel();
        contentPane.setOpaque(true);
        contentPane.setBorder(BorderFactory.createLineBorder(
                                    Color.DARK_GRAY.darker(), 5, true));
        contentPane.setBackground(Color.WHITE);

        add(contentPane, BorderLayout.CENTER);
        pack();
        setVisible(true);
    }

    public Insets getInsets()
    {
        return (new Insets(30, 20, 10, 20));
    }

    public Dimension getPreferredSize()
    {
        return (new Dimension(200, 400));
    }

    public static void main(String\u005B\u005D args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                new InsetTesting().createAndDisplayGUI();
            }
        });
    }
}

Here is the output of the same :