code: package org.omnetpp.common;
  
  import org.eclipse.core.runtime.IStatus;
  import org.eclipse.core.runtime.Status;
  import org.eclipse.core.runtime.preferences.ConfigurationScope;
  import org.eclipse.jface.resource.ImageDescriptor;
  import org.eclipse.jface.resource.ImageRegistry;
  import org.eclipse.swt.graphics.Image;
  import org.eclipse.ui.plugin.AbstractUIPlugin;
  import org.eclipse.ui.preferences.ScopedPreferenceStore;
  import org.osgi.framework.BundleContext;
  
  /**
   * The activator class controls the plug-in life cycle
   */
  public class CommonCorePlugin extends AbstractUIPlugin {
  
      // The plug-in ID
      public static final String PLUGIN_ID = "org.omnetpp.common.core";
  
      // The shared instance
      private static CommonCorePlugin plugin;
  
      // global preference store (per installation)
      private ScopedPreferenceStore configPreferenceStore;
  
      /**
       * The constructor
       */
      public CommonCorePlugin() {
      }
  
      /*
       * (non-Javadoc)
       * @see org.eclipse.core.runtime.Plugins#start(org.osgi.framework.BundleContext)
       */
      public void start(BundleContext context) throws Exception {
          super.start(context);
          plugin = this;
      }
  
      /*
       * (non-Javadoc)
       * @see org.eclipse.core.runtime.Plugin#stop(org.osgi.framework.BundleContext)
       */
      public void stop(BundleContext context) throws Exception {
          plugin = null;
          super.stop(context);
      }
  
      /**
       * Returns the shared instance
       *
       * @return the shared instance
       */
      public static CommonCorePlugin getDefault() {
          return plugin;
      }
  
      /**
       * Returns an image descriptor for the image file at the given
       * plug-in relative path
       *
       * @param path the path
       * @return the image descriptor
       */
      public static ImageDescriptor getImageDescriptor(String path) {
          return imageDescriptorFromPlugin(PLUGIN_ID, path);
      }
  
      /**
       * Creates an image. IMPORTANT: The image is NOT cached! Callers
       * are responsible for disposal of the image.
       */
      public static Image getImage(String path) {
          return getImageDescriptor(path).createImage();
      }
  
      /**
       * Like getImage(), but the image gets cached in an internal image registry,
       * so clients do not need to (moreover, must not) dispose of the image.
       */
      public static Image getCachedImage(String path) {
          ImageRegistry imageRegistry = getDefault().getImageRegistry();
          Image image = imageRegistry.get(path);
          if (image==null) {
              image = getImage(path);
              imageRegistry.put(path, image);
          }
          return image;
      }
  
      public static void logError(Throwable exception) {
          logError(exception.toString(), exception);
      }
  
      public static void logError(String message, Throwable exception) {
          if (plugin != null) {
              plugin.getLog().log(new Status(IStatus.ERROR, PLUGIN_ID, 0, message, exception));
          }
          else {
              System.err.println(message);
              if (exception!=null)
                  exception.printStackTrace();
          }
      }
  
      public static ScopedPreferenceStore getConfigurationPreferenceStore() {
          // Create the preference store lazily.
          if (getDefault().configPreferenceStore == null) {
              getDefault().configPreferenceStore = new ScopedPreferenceStore(new ConfigurationScope(), PLUGIN_ID);
          }
          return getDefault().configPreferenceStore;
      }
  }
  