public static class CommandAction
extends java.lang.Object
IAction on the menubar, the toolbar, or a popup menu
by delegating all required behaviour to a Command.
All aspects of the action are delegated,
namely the enablement state, the menu text, the toolbar icon, and the help tip text.
A derived class implements createActionCommand
to return a command based on the EditingDomain and the collection of selected objects.
This class can also be used to implement actions not based on a selection,
in that case the method selectionChanged should be overridden to do nothing.