// JFrameDemo
// Demos JFrame
// Calculates area of a rectangle
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class JFrameDemo extends JFrame {
	private JLabel lengthLabel, widthLabel, areaLabel;
	private JTextField lengthField, widthField, areaField;
	private JButton calcButton, exitButton;

	private int l, w;

	public JFrameDemo( ) {
		super( "JFrame Demo Application" );

		Container c = getContentPane( );
		c.setLayout( new FlowLayout( ) );

		lengthLabel = new JLabel( "Enter length as an integer" );
		c.add( lengthLabel );
		lengthField = new JTextField( 10 );
		c.add( lengthField );

		widthLabel = new JLabel( "Enter width as an integer" );
		c.add( widthLabel );
		widthField = new JTextField( 10 );
		c.add( widthField );

		areaLabel = new JLabel( "AREA" );
		c.add( areaLabel );
		areaField = new JTextField( 10 );
		c.add( areaField );

		calcButton = new JButton( "Calculate" );
		calcButton.addActionListener(
			new ActionListener( ) {
				public void actionPerformed( ActionEvent e ) {
					l = Integer.parseInt( lengthField.getText( ) );
					w = Integer.parseInt( widthField.getText( ) );
					areaField.setText( l * w + " square units" );
				}
			}
		);
		c.add( calcButton );

		exitButton = new JButton( "Quit" );
		exitButton.addActionListener(
			new ActionListener( ) {
				public void actionPerformed( ActionEvent e ) {
					System.exit( 0 );
				}
			}
		);
		c.add( exitButton );
	}

	public static void main( String args[ ] ) {
		JFrameDemo areaWindow = new JFrameDemo( );
		areaWindow.setSize( 155, 250 );
		areaWindow.show( );

		areaWindow.addWindowListener(
			new WindowAdapter( ) {
				public void windowClosing( WindowEvent e ) {
					System.exit( 0 );
				}
			}
		);
	}
}