I am spending the time between the years for an extension of the German Xojo non-manual, and I thought it would be better to understand each feature before I simply translate the LR entries. 
One thing I cannot figure out is: What are the optional x, y, width, height parameters in Canvas.Scroll good for? LR says they define the area to scroll, but this is basically the contents placed on it – they move according to moveControls –, and the rest must be done in the paint event. I thought the parameters would define an area for the paint event, but they don’t. What am I missing here?
Thanks a lot!