void QItemDelegate::paint ( QPainter * painter, const QStyleOptionViewItem & option, const QModelIndex & index ) const [virtual] Renders the delegate using the given painter and style option for the item specified by index. When reimplementing this function in a subclass, you should update the area held by the option's rect variable, using the option's state variable to determine the state of the item to be displayed, and adjust the way it is painted accordingly. For example, a selected item may need to be displayed differently to unselected items, as shown in the following code: if (option.state & QStyle::State_Selected) painter->fillRect(option.rect, option.palette.highlight()); int size = qMin(option.rect.width(), option.rect.height()); int brightness = index.model()->data(index, Qt::DisplayRole).toInt(); double radius = (size/2.0) - (brightness/255.0 * size/2.0); if (radius == 0.0) return; painter->save(); painter->setRenderHint(QPainter::Antialiasing, true); painter->setPen(Qt::NoPen); if (option.state & QStyle::State_Selected) painter->setBrush(option.palette.highlightedText()); else ...