// NOTES:
// - any of the calls below may return NULL. So check for it!
// - some of the calls below will work ONLY from the eclipse UI thread!
// - to switch to the UI thread from anywhere, use Display.getCurrent() and then use  syncExec(Runnable runnable)
// - be careful about deadlocks and significant delays here.
IWorkbench iworkbench = PlatformUI.getWorkbench();
IWorkbenchWindow iworkbenchwindow = iworkbench.getActiveWorkbenchWindow();
IWorkbenchPage iworkbenchpage = iworkbenchwindow.getActivePage();
IEditorPart ieditorpart = iworkbenchpage.getActiveEditor();

 IResource extractResource(IEditorPart editor) {
      IEditorInput input = editor.getEditorInput();
      if (!(input instanceof IFileEditorInput))
         return null;
      return ((IFileEditorInput)input).getFile();
   }