sanity check: deriving from Gtk::Range

[Joaquim Schmidlap <schmidlap schmidlap org>]

I need to create a Dial type widget, the standard speedometer sort of  
thing. I looked around for something open source that would work but  
came up dry, so I'm resigned to building my own.

It seems like the right thing to do would be to derive from Range.  
Could anyone give me a quick sanity check on this? Good idea, bad  
idea, impossible? Certainly, the interface is right, but I don't know  
how much of the wheel I'll have to reinvent once I get in there. If  
anyone knows of a successful example of this, that would be  
fantastic, too.

Or, if this idea isn't great, does anyone have a suggested alternative?