QScroolArea tutorial

Qt : QScroolArea PaintEvent I want to create paintEvent in QScroolArea. This is a tutorial how to implement QScroolArea paintEvent method.  I have confused how to create drawingEvent in the QScroolArea. So, after searching and try some of method, I create tutorial  how QScroolArea implement paintEvent. This is the steps how to implemnt QScroolArea paintEvent [...]