/**
 * A Simple stand-alone GUI program based on Swing.
 *  
 * This example uses a class that extends JFrame
 * instead of creating a JFrame object!
 *
 * Similar to ButtonText sample, but this one
 * puts the text field at top and not in BorderLayout.CENTER
 * so that it's size is preserved.
 *
 * This class also implements ActionListener, so we 
 * can use it to handle Action events
 *
 * The main creates a window with a bunch of buttons 
 * and a textfield.
 * Uses a JPanel to hold the buttons (container component).
 *
 * Whenever the user presses a button the button text is appended to
 * the textfield
 *
 * @author Dave Hollinger
 * @version 1.0
 */

import javax.swing.*;
import java.awt.*;       // needed for Container
import java.awt.event.*;  // needed for event types (listeners)


class ButtonText2 extends JFrame implements ActionListener {

  // The textfield must not be anonymouse, since we want to	
  // be able to modify it from event handlers

  JTextField jt;


  public static void main(String [] args) {
	ButtonText2 bt = new ButtonText2();
  }

  // Constructor sets up the window and gets things rolling.

  ButtonText2() {

	Container c = getContentPane();
	// set up layout manager
	c.setLayout(new BorderLayout(10,10));
	
	// add single text Area
	jt = new JTextField();
	jt.setSize(100,20);
	jt.setFont(new Font("Arial",Font.BOLD,16));
	jt.setBackground(Color.WHITE);
	jt.setForeground(Color.BLUE);
	c.add(jt,BorderLayout.NORTH);

	// add a button panel 
	c.add( createButtonPanel(), BorderLayout.CENTER );
	

	// establish what happens when the window is closed
	// (without this the program would keep running!)
	setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	// set the size
	setSize(200,200);
	// turn it on
	setVisible(true);
  }


  JPanel createButtonPanel() {
	// create a JPanel with a bunch of buttons in it arranged in
	// a grid.
	JPanel jp = new JPanel();

	// establish the layout manager
	// 2 rows, 3 cols everything 5 pixels apart
	jp.setLayout( new GridLayout(2,3,5,5));

	// add a bunch of buttons
	for (int i=0;i<6;i++) {
	  JButton j = new JButton(new Integer(i).toString());
	  // change the font
	  j.setFont(new Font("Courier",Font.BOLD,20));

	  // change the colors
	  j.setBackground(Color.WHITE);
	  j.setForeground(Color.BLACK);

	  // set up the listener for this button
	  // NOTE: We listen to ourself (we are an ActionListener!).
	  j.addActionListener(this);

	  // add the button to the panel
	  jp.add(j);
	}
	return(jp);
  }

  // here is the method required as an ActionListener
  // (there is only one!)

  public void actionPerformed(ActionEvent e) {

	// find out what the action was
	// (for buttons, this is the button text by default)
	String act = e.getActionCommand();

	jt.setText(jt.getText() + act );
  }

}