how to change dragMoveEvent target borders

Howdy,

I have a QTreeView with a custom model, and internal DnD implemented. Everything
works fine. The issue I am having is with the highlights shown when drag moving. When moving the mouse during a drag operation, the underlying items are drawn with borders. Depending on whether the cursor is above, on, or below the item, the border of the underlying item is either the whole rectangle, or a line above or below. The problem for me is that this border is one pixel wide and hard to see. I would like to change the width.

I have been looking at the source code in QAbstractItemView::dragMoveEvent and
cannot figure out how to change the width of the border when being dragged over.
Can anyone offer a suggestion? If there were a way using stylesheets, that would
be fine, since I am using them anyway.

thanks,
Danny