# File vtk/gtk/GtkVTKRenderWindowInteractor.rb, line 160
    def _GetCtrlShift(self, event)
        ctrl, shift = 0, 0        
        if ((event.state & GDK.CONTROL_MASK) == GDK.CONTROL_MASK)
            ctrl = 1
        end
        if ((event.state & GDK.SHIFT_MASK) == GDK.SHIFT_MASK)
            shift = 1
        end
        return ctrl, shift
    end