Java – let actionlistener listen for changes in jtextfield instead of just entering?

So you may know that if you have a text field and add an actionlistener, it will only listen to the buttons However, I want my actionlistener to listen to the changes in the text So basically I have this:

public static JPanel mainPanel() { 
    JPanel mainp = new JPanel(); 
    JTextArea areap = new JTextArea("Some text in the textarea"); 
    JTextField fieldp = new JTextField("Edit this"); 
    areap.setEditable(false); 
    fieldp.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO Auto-generated method stub
             if(//change in textfield,for instance a letterpress or space bar)
                   { 
                        //Do this
                   } 
        }
    });
    mainp.add(areap);
    mainp.add(fieldp); 
    return mainp;
}

In any way, can I listen to changes in the text (as recorded in the actionperformed event)?

Solution

Reply from @ jrl

Use basic documents:

myTextField.getDocument().addDocumentListener();