GtkTree::set_view_lines
void
      set_view_lines
     (int
      flag
     ); 
    
     Sets whether or not lines between nodes and children should be drawn. If
     flag evaluates to true
     (flag > 0) connecting lines between nodes and
     children will be drawn. If flag evaluates to
     false (flag <= 0) connecting
     lines between nodes and children will not be drawn. By default tree's begin
     with view lines set to one.