ExtJS - Disable Combobox onWidgetAttach not working

I am displaying a combobox in a grid. The value for combobox comes from a local store. The combobox needs to be disabled for one of the rows. I used widget.setDisabled(true). It seems to work but when i click, the combo box is showing me all the values.

Below is my code:

{
xtype: 'widgetcolumn',
text: 'Code',
dataIndex: 'code',
widget: {
    xtype: 'codecombo'
},
editor: {
    xtype: 'codecombo'
},
onWidgetAttach: function (col, widget, rec) 
{
    widget.setDisabled(rec.get('type') === 2);
}
}

Thanks!