- Update plugin interface

git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@658 3ecf2c5c-341e-0410-92b4-d18e462d057c

src/backend/plugin.hh

@@ -23,14 +23,42 @@
 
 #include "config.h"
 
+#include <glibmm/ustring.h>
+
 /** \file plugin.hh 
  * All loadable modules that want to act as plugins
  * for SGPEMv2 should implement this interface. */
 
-// FIXME Add Singleton LoadPlugin class.
-/*
-  class LoadPlugin {
-  };
+namespace sgpem 
+{
+
+	/** \brief The interface a specific plugin should implement
+	 *
+         * Only the header file containing this interface 
+	 * should be provided by the backend library. Every plugin 
+	 * will then implement its set of static functions. 
+	 * Thus every plugin will export these very symbols 
+	 * outside its DSO.
 	 */
+	class SG_DLLEXPORT Plugin
+	{
+		/** \brief Called when a plugin is loaded and enabled
+		 *
+		 * Sets up the plugin's initial state and 
+		 * performs needed actions before its usage can start.
+		 */
+		static void          on_init();
+
+		static void          on_exit();
+		static Glib::ustring describe();
+		static Glib::ustring get_name();
+		static Glib::ustring get_author();
+		static float         get_version();
+
+	private:
+		SG_DLLLOCAL Plugin();
+	}; //~ class Plugin
+
+} //~ namespace sgpem
 
 #endif