             ref     = {'cols_drag_bar'}
             axis    = {'x'}
             onStop  = {handle_stop}
+            onMouseDown = {(e) => e.preventDefault()}
             >
             <div style={cols_drag_bar}> </div>
         </Draggable>

        data = @get_data('column')
        <div
            className = {'smc-vfill'}
            ref       = {'rows_container'} >
            <div className={'smc-vfill'} style={data.style_first}>
                {@render_one(data.first)}
            </div>

            style_first  : {display:'flex', overflow:'hidden', flex:pos,   border:frame_border}
            second       : @props.frame_tree.get('second')
            style_second : {display:'flex', overflow:'hidden', flex:1-pos, border:frame_border}

        if flex_direction == 'row'
            data.outer_style = {display:'flex', flexDirection:'row', flex:1}
        else
            data.outer_style = undefined
        return data

    render_cols: ->
        data = @get_data('row')
        <div
            ref   = {'cols_container'}
            style = {data.outer_style}>
            <div className={'smc-vfill'} style={data.style_first}>
                {@render_one(data.first)}
            </div>
