To add a new action to piy, you must implement the Action interface and then place the action in this package. Piy automatically detects any valid Action classes in this package.
It is recommended (but not required) that actions hae a relevant descriptor class which describes the action. The descriptor class is a class which extends ActionDescriptor, providing information to piy such as the name of the action and the icon to display on the piy toolbar. (Ideally, icons should be placed in the piy/action directory.)