Bug 169591 [Common Navigator] Show In fails for editor inputs
The show(ShowInContext) method for CommonNavigator only considers the selection of the context. When Show In Project Explorer is performed from an editor, the selection is empty and the input is provided. Unfortunately, this is problematic, as the show-in target needs to adapt the input to an IFile so this will probably need to have some sort of extension so that the Project Explorer can plug-in the proper support.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonNavigator.java
*          &lt;/extension&gt; 
 *    
 * </pre>
 * 
 * </p> 
 * Clients that wish to extend the view menu provided via the
 * <b>org.eclipse.ui.popupMenu</b>s extension may specify the the <i>popupMenuId</i>
 * specified by <b>org.eclipse.ui.navigator.viewer</b> (or a nested <b>popupMenu</b> element) of their target viewer
 * as their target menu id.
 * 
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 *  
 * @since 3.2
 */
public class CommonNavigator extends ViewPart implements ISetSelectionTarget, ISaveablePart, ISaveablesSource, IShowInTarget {
 
	/**
	 * 
	 */
	private static final Class INAVIGATOR_CONTENT_SERVICE = INavigatorContentService.class;
	private static final Class COMMON_VIEWER_CLASS = CommonViewer.class;
	private static final Class ISHOW_IN_TARGET_CLASS = IShowInTarget.class;
	/**
	 * <p>
	 * Used to track changes to the {@link #isLinkingEnabled}&nbsp;property.
	 * </p>
	 */
	public static final int IS_LINKING_ENABLED_PROPERTY = 1;