java.awt.event.FocusAdapter Maven / Gradle / Ivy

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*/


  


package java.awt.event;

/** 
 * An abstract adapter class for receiving keyboard focus events.
 * The methods in this class are empty. This class exists as
 * convenience for creating listener objects.
 * 

 * Extend this class to create a FocusEvent listener 
 * and override the methods for the events of interest. (If you implement the 
 * FocusListener interface, you have to define all of
 * the methods in it. This abstract class defines null methods for them
 * all, so you can only have to define methods for events you care about.)
 * 
 * Create a listener object using the extended class and then register it with 
 * a component using the component's addFocusListener 
 * method. When the component gains or loses the keyboard focus,
 * the relevant method in the listener object is invoked,
 * and the FocusEvent is passed to it.
 *
 * @see FocusEvent
 * @see FocusListener
 * @see Tutorial: Writing a Focus Listener
 * @see Reference: The Java Class Libraries (update file)
 *
 * @author Carl Quinn
 * @version 1.15 01/23/03
 * @since 1.1
 */
public abstract class FocusAdapter implements FocusListener
{

    public FocusAdapter() { }

    /** 
     * Invoked when a component gains the keyboard focus.
     */
    public void focusGained(FocusEvent e) { }

    /** 
     * Invoked when a component loses the keyboard focus.
     */
    public void focusLost(FocusEvent e) { }
}