How to owner draw the page control transparent in the QScrollBar control?

I have two questions, they are as follow:
1) I use the QStyle to owner draw the QScrollBar control, now I need draw its page control transparent. How to implement it when I draw the CE_ScrollBarAddPage and CE_ScrollBarSubPage? thanks.
2) I want to set one widget's background use the linear Gradient Brush. Now I can implement it by subclass the widget and override the widget's paintevent. Is it exist the simple method to implement? thanks.