Explicit-Event Handling - Java

An alternate way to handle events is to sub class the components and override the method that receives and dispatches event. For example you can drive a class from Button class and override the processActionEvent() method. The default action of the processActionEvent() method is to dispatch the event to the event listeners.

Example1:

Class OKButton extends Button
{
Public OKButton (String caption)
{
super(caption);
//enable processing of action events
enableEvents(AWTEvent.Action_Event_Mask);
}
Public void processActionEvent(ActionEvent e)
{
// process event, and call superclass method 
// as it calls actionPerformed() method
super.processActionEvent(action);
}
}

A subclass can act as an event listener for itself as shown in the following code:

Class OKButton extends Button implements ActionListener
{
Public OKButton(String caption)
{
super(caption);
//add an action listener to the button
addActionListener(this);
}
Public void actionPerformed(ActionEvent ae)
{
// code to process event
}
}

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