barlines - thickness and location

[Jarkko Sipilä (Koti)]

I would need a software which draws the barlines over the
first note of the bar as a thin line. The barlines should not affect the
distance between the notes.

Like this:
http://webusers.siba.fi/~jsipila/trio.jpg

Which classes do drawing of the barlines and control location and thickness of 
the barlines?

Thanks, Jarkko Sipilä