Text Listener for events TextListener-on TextArea-TextField

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

public class TextEventExample extends Applet 
                           implements ActionListener {
    TextField textObj;
    TextArea textAreaObj1;
    TextArea textAreaObj2;

    public void init() {
	Button button = new Button("Empty");
	button.addActionListener(this);

	textObj = new TextField(25);
	textObj.addActionListener(new MyCustomActListener());
	textObj.addTextListener(new MyCustomTxtListener("Text Field"));

        textAreaObj1 = new TextArea(5, 20);
	textAreaObj1.addTextListener(new MyCustomTxtListener("Text Area"));

	textAreaObj2 = new TextArea(5, 20);
	textAreaObj2.setEditable(false);

	GridBagLayout gridbag = new GridBagLayout();
	GridBagConstraints gridBagConstrain = new GridBagConstraints();
	setLayout(gridbag);
	gridBagConstrain.fill = GridBagConstraints.BOTH;
	gridBagConstrain.weightx = 1.0;

	 
	Panel leftPanel = new Panel();
	leftPanel.setLayout(new BorderLayout());
	leftPanel.add("North", textObj);
	leftPanel.add("Center", textAreaObj1);

	gridBagConstrain.gridheight = 2;
	gridbag.setConstraints(leftPanel, gridBagConstrain);
	add(leftPanel);

	gridBagConstrain.weighty = 1.0;
	gridBagConstrain.gridwidth = GridBagConstraints.REMAINDER;
	gridBagConstrain.gridheight = 1;
	gridbag.setConstraints(textAreaObj2, gridBagConstrain);
	add(textAreaObj2);

	gridBagConstrain.weighty = 0.0;
	gridbag.setConstraints(button, gridBagConstrain);
	add(button);
    // set focus to it.
	textObj.requestFocus();
    }

    class MyCustomTxtListener implements TextListener {
	String preface;
        String newline;

	public MyCustomTxtListener(String source) {
	    lineSeparator = System.getProperty("line.separator");
	    preface = source
		      + " text value changed."
		      + lineSeparator
		      + "   First 10 characters: \"";
	}

        public void textValueChanged(TextEvent e) {
	    TextComponent tc = (TextComponent)e.getSource();
	    String s = tc.getText();
	    try {
		s = s.substring(0, 10);
	    } catch (StringIndexOutOfBoundsException ex) {
	    }

	    textAreaObj2.append(preface + s + "\"" + lineSeparator);

            //Scroll down, unless the peer still needs to be created.
	    if (textAreaObj2.isValid()) {
	        textAreaObj2.setCaretPosition(java.lang.Integer.MAX_VALUE);
	    } 
	}
    }

    class MyCustomActListener implements ActionListener {
    
        public void actionPerformed(ActionEvent e) {
	    int selStart = textAreaObj1.getSelectionStart();
	    int selEnd = textAreaObj1.getSelectionEnd();

            textAreaObj1.replaceRange(textObj.getText(),
	                          selStart, selEnd);
            textObj.selectAll();
        }
    }

   
    public void actionPerformed(ActionEvent e) {
	textAreaObj2.setText("");
	// set focus to it.
	textObj.requestFocus();
    }
}