C++ (Qt)
void ProgressBarDelegate::paint( QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index ) const
{
	if( !index.isValid() )
		return;
 
	painter->save();
	int val = index.data( Qt::DisplayRole ).toInt();
	if( val )
	{
		QStyleOptionProgressBar opt;
		opt.state = option.state;
		opt.direction = option.direction;
		opt.rect = option.rect;
		opt.fontMetrics = option.fontMetrics;
		opt.palette = option.palette;
		opt.minimum = 0;
		opt.maximum = 100;
		opt.progress = val;
		opt.textAlignment = Qt::AlignCenter;
		opt.textVisible = true;
		opt.text = QString( "%1 %" ).arg( val );
 
		QProgressBar bar;
		QApplication::style()->drawControl( QStyle::CE_ProgressBar, &opt, painter, &bar );
	}
	painter->restore();
}