a semantic event which indicates that a component-defined action occurred.
This high-level event is generated by a component (such as a Button)
when the component-specific action occurs (such as being pressed).
The event is passed to every XActionListener object
that registered to receive such events using the component's
addActionListener method.
The object that implements the XActionListener interface
gets this ActionEvent when the event occurs. The listener is therefore
spared the details of processing individual mouse movements and mouse
clicks, and can instead process a "meaningful" (semantic) event like
"button pressed".
