Beginning of DocumentListener

Listing 6 shows the beginning of the definition, instantiation, and registration

• of a DocumentListener object
• on the object of type Document
• that is encapsulated in the Red text field.

    redField.getDocument().addDocumentListener(
      new DocumentListener(){
      
        public void changedUpdate(DocumentEvent e){
          //Empty method - not needed
        }//end changedUpdate