Another example:
Imagine you want to increase the thickness of the change bar. Where to start and what classes has to be changed?
void RowPainter::paintChangeBar() sounds like it :) ;) andpi_.pain.fillRectangle(5, yo_ - row_.ascent(), 3, height, Color_changebar);
5 is the offset from the left border, and 3 is the thickness. VIncent