def _get_idxs_for_all_rois(GTCodes, element_infos):
    """Get indices of ROIs within the element_infos dataframe.

    (Internal)

    """
    roi_labels = list(GTCodes.loc[GTCodes.loc[:, ('is_roi')] == 1, 'group'])
    idxs_for_all_rois = []
    for idx, elinfo in element_infos.iterrows():
        if elinfo.group in roi_labels:
            idxs_for_all_rois.append(idx)
    return idxs_for_all_rois
