How can I "flip" the arrows in a QSpinBox so that when you push down, the number increases and when you push up, the number decreases?

I want to use the spinbox to set depth-value so my users found it more intuitive that down would be an increase of depth.

I have subclassed the QSpinBox (actually a QDoubleSpinBox) and overridden the wheelEvent so that one is taken care of.

I could look for mousepress and see if the mouse is inside the up or down arrow, maybe, but when the value is 0 (minValue), the down-arrow is gray, so just overriding the values here would not be any good. I want the up-arrow to be gray when value is at minValue.

I've tried googling for this and the closest I've come is to completely redefine the QStyle painting routine. I found this also in "C++ GUI programming with Qt 4". This seemed overly complex and I don't want to redefine the style if this means that I would set the spinBox style to something that may be unlike the native look in different OS'es.

Is there any painting routine I could relatively easily override where I just reposition the arrows? Or any other place I should look?