import java.awt.Component;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import java.awt.Insets;

/*
  Author:  James Tam
  Version: March 29, 2021

*/

public class MyFrame extends JFrame
{
    private JButton button1;
    private JButton button2;
    private JLabel label1;
    private JLabel label2;
    private GridBagLayout aLayout;
    private GridBagConstraints aConstraint;
    private MyWindowListener aListener;

    public MyFrame ()
    {
	aConstraint = new GridBagConstraints();
        button1 = new JButton("Left");
        button2 = new JButton("Right");
        label1 = new JLabel("Top left");
        label2 = new JLabel("Top right");
        aListener = new MyWindowListener();
        addWindowListener(aWindowListener); // Calling method of super class.
	aConstraint.insets = new Insets(1,1,1,1);
        aLayout = new GridBagLayout();
        setLayout(aLayout);     // Calling method of super class.
        addWidget(label1,0,0,1,1);
        addWidget(label2,1,0,1,1);
        addWidget(button1,0,1,1,1);	
        addWidget(button2,1,1,1,1);
    }

    public void addWidget (Component widget, int x, int y, int w, int h)
    {
        aConstraint.gridx = x;
        aConstraint.gridy = y;
        aConstraint.gridwidth = w;
        aConstraint.gridheight = h;
        aLayout.setConstraints (widget, aConstraint);
        add(widget);        // Calling method of super class.
    }
}