import javax.swing.*;					// all of the J components
import java.awt.event.*;				// ActionListener, ActionEvent

// this program creates a simple GUI of an instruction, an input field and an output field
// when the user enters text into the input field and presses the <enter> key, the ActionEvent
// occurs invoking actionPerformed which then takes the input and moves it to the output JLabel

public class TextFieldExample
{
	public static void main(String[] args)
	{
		JFrame f=new JFrame("text field example");
		f.setSize(500,100);
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		TPanel tp=new TPanel();
		f.add(tp);
		f.setVisible(true);
	}
	
	public static class TPanel extends JPanel implements ActionListener
	{
		private JLabel lab1, out;				// lab1 is the instruction ("Enter some text"), out is the output JLabel
		private JTextField in;					// in is the input JTextField where the user will enter text
		
		public TPanel()
		{
			lab1=new JLabel("Enter some text");		// instantiate GUI components
			in=new JTextField("",10);
			out=new JLabel("          ");
			add(lab1);								// use a simple flow layout to position these three items on this JPanel in the same row
			add(in);
			add(out);
			in.addActionListener(this);				// the in JTextField will respond when the <enter> key is pressed
		}
		
		public void actionPerformed(ActionEvent e)	// upon <enter> from the in JTextField, actionPerformed is invoked
		{
			out.setText(in.getText());				// get the text entered into in and copy it to the JLabel out
			in.setText("");							// reset in to be empty
		}
		
	}
}