code: @Override
    public void fillActionBars(IActionBars actionBars) {
      actionBars.setGlobalActionHandler(ActionFactory.DELETE.getId(),
          new DFSAction(DFSActions.DELETE));
      actionBars.setGlobalActionHandler(ActionFactory.REFRESH.getId(),
          new DFSAction(DFSActions.REFRESH));
  
      if (site == null)
        return;
  
      if ((site.getStructuredViewer().getSelection() instanceof IStructuredSelection)
          && (((IStructuredSelection) site.getStructuredViewer()
              .getSelection()).size() == 1)
          && (((IStructuredSelection) site.getStructuredViewer()
              .getSelection()).getFirstElement() instanceof DFSFile)) {
  
        actionBars.setGlobalActionHandler(ICommonActionConstants.OPEN,
            new DFSAction(DFSActions.OPEN));
      }
  
      actionBars.updateActionBars();
    }
docs: /* @inheritDoc