class PixmapItemDelegate(QtGui.QStyledItemDelegate):
    def paint(self, painter, option, index):
        painter.save()

        if (option.state & QtGui.QStyle.State_MouseOver):
            pen = QtGui.QPen(QtCore.Qt.yellow)
        else:
            pen = QtGui.QPen(QtCore.Qt.transparent)
        pen.setWidth(2)
        painter.setPen(pen)
        painter.setBrush(QtGui.QBrush(QtCore.Qt.transparent))
        painter.drawRect(option.rect)

        painter.restore()

        super(PixmapItemDelegate, self).paint(painter, option, index)

if ( option.state & QtGui.QStyle.State_MouseOver and
    not option.state & QtGui.QStyle.State_Selected ):