code: package defaultpackage;
  
  import java.util.HashSet;
  import java.util.Set;
  
  import org.eclipse.sirius.business.api.componentization.ViewpointRegistry;
  import org.eclipse.sirius.viewpoint.description.Viewpoint;
  import org.eclipse.ui.plugin.AbstractUIPlugin;
  import org.osgi.framework.BundleContext;
  
  /**
   * The activator class controls the plug-in life cycle
   */
  public class Activator extends AbstractUIPlugin {
      // The plug-in ID
      public static final String PLUGIN_ID = "IFMLEditorDesign";
  
      // The shared instance
      private static Activator plugin;
  
      private static Set<Viewpoint> viewpoints; 
  
      /**
       * The constructor
       */
      public Activator() {
      }
  
      /*
       * (non-Javadoc)
       * 
       * @see org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.BundleContext)
       */
      public void start(BundleContext context) throws Exception {
        super.start(context);
  	  plugin = this;
  	  viewpoints = new HashSet<Viewpoint>();
  	  viewpoints.addAll(ViewpointRegistry.getInstance().registerFromPlugin(PLUGIN_ID + "/description/IFML.odesign")); 
      }
  
      /*
       * (non-Javadoc)
       * 
       * @see org.eclipse.ui.plugin.AbstractUIPlugin#stop(org.osgi.framework.BundleContext)
       */
      public void stop(BundleContext context) throws Exception {
  	plugin = null;
  	if (viewpoints != null) {
  	    for (final Viewpoint viewpoint: viewpoints) {
  		ViewpointRegistry.getInstance().disposeFromPlugin(viewpoint);
  	    }
  	    viewpoints.clear();
  	    viewpoints = null; 
  	}
  	super.stop(context);
      }
  
      /**
       * Returns the shared instance
       * 
       * @return the shared instance
       */
      public static Activator getDefault() {
  	return plugin;
      }
  }
  