java.util.Observer Maven / Gradle / Ivy

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package java.util;

/** 
 * A class can implement the Observer interface when it
 * wants to be informed of changes in observable objects.
 *
 * @author  Chris Warth
 * @version 1.16, 02/02/00
 * @see     java.util.Observable
 * @since   JDK1.0
 */
public interface Observer
{

    /** 
     * This method is called whenever the observed object is changed. An
     * application calls an Observable object's
     * notifyObservers method to have all the object's
     * observers notified of the change.
     *
     * @param   o     the observable object.
     * @param   arg   an argument passed to the notifyObservers
     *                 method.
     */
    public void update(Observable o, Object arg);
}