The plugin central factory. ... List of all member functions. virtual  ~QNPlugin  ()  . ... One instance of this object is created when the plugin is first needed, by calling QNPlugin::create (), which must be implemented in your plugin code to return some derived class of QNPlugin. ... This may only be used by the constructor derived class returned by plugin's implementation of the QNPlugin::create () function. ... Override to return a reference to the Java class that represents the plugin. ...