'Selected item in the preview list has changed.
Set the new description and large preview image.'

def __onSelectionChanged(self, *args):

    rows = self.__previewList.selectedIndexes()
    if rows:
        index = rows[0]
        self.__currentIndex = index.row()
    else:
        index = QModelIndex()
        self.__currentIndex = (-1)
    self.__update()
    self.currentIndexChanged.emit(self.__currentIndex)
