How to use validator function to set visibility of widgets

Hello 

I have created one data table . In that data table there are 3 columns like activity, activity value type and activity widget type. Now for 1st 4 activities activity widget type is textbox and for last one it is buttonbar. Now i am giving this data to collection widget .In the base mashup i have two widgets as text box and button bar. I want only text box widget should be visible  if the activity widget type is textbox and if activity widget type is button bar then only button bar widget should be visible.

 Please help