[pygtk] scrollbar query

[Bentley Harry]

Im trying to attach a scrollbar to a viewport containing a textview.  I 
realise it would be easier to use a scrolled window but i want to capture 
information about whether the scrollbar is being scrolled up or down which 
is not supplied by the scrolled window (unless it is scrolled using the 
mouse-wheel). 

However, when i run my program the viewport comes up the size of the entire 
textfile (which is too big to fit on the screen) and the scrollbar 
thumbwheel is the same size as the trough so therefore you cannot scroll up 
or down.  How do i make the viewport only display a portion of the textview 
at a time and allow scrolling up and down using the scrollbar. 

Thanks 

te1l