QListView/QAbstractItemView and list internal drag & drop

[Infinity]

I solved the second problem. To allow drops only outside the items and not over the items I use the following flags reimplementation in my model:

Qt::ItemFlags FieldModel::flags(const QModelIndex &index) const
{
    if (!index.isValid() || index.row() >= m_fields.count() || index.model() != this)
            return Qt::ItemIsDropEnabled; // we allow drops outside the items
    return QAbstractListModel::flags(index) | Qt::ItemIsUserCheckable | Qt::ItemIsDragEnabled;
}

Qt::ItemFlags FieldModel::flags(const QModelIndex &index) const
{
    if (!index.isValid() || index.row() >= m_fields.count() || index.model() != this)
            return Qt::ItemIsDropEnabled; // we allow drops outside the items
    return QAbstractListModel::flags(index) | Qt::ItemIsUserCheckable | Qt::ItemIsDragEnabled;
}

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This solution is taken from qtbase/src/widgets/qlistwidget.cpp.

Edit: I also solved the first problem. These are the correct reimplementations of insertRows and removeRows in my case:

bool FieldModel::insertRows(int row, int count, const QModelIndex &parent)
{
    if (count < 1 || row < 0 || row > rowCount() || parent.isValid())
        return false;
    beginInsertRows(QModelIndex(), row, row + count - 1);
    for(int index = row, end = row + count; index < end; ++index)
        m_fields.insert(index, p(KnownField::Invalid, false));
    endInsertRows();
    return true;
}
 
bool FieldModel::removeRows(int row, int count, const QModelIndex &parent)
{
    if (count < 1 || row < 0 || (row + count) > rowCount() || parent.isValid())
        return false;
    beginRemoveRows(QModelIndex(), row, row + count - 1);
    for(int index = row, end = row + count; index < end; ++index)
        m_fields.removeAt(index);
    endRemoveRows();
    return true;
}

bool FieldModel::insertRows(int row, int count, const QModelIndex &parent)
{
    if (count < 1 || row < 0 || row > rowCount() || parent.isValid())
        return false;
    beginInsertRows(QModelIndex(), row, row + count - 1);
    for(int index = row, end = row + count; index < end; ++index)
        m_fields.insert(index, p(KnownField::Invalid, false));
    endInsertRows();
    return true;
}

bool FieldModel::removeRows(int row, int count, const QModelIndex &parent)
{
    if (count < 1 || row < 0 || (row + count) > rowCount() || parent.isValid())
        return false;
    beginRemoveRows(QModelIndex(), row, row + count - 1);
    for(int index = row, end = row + count; index < end; ++index)
        m_fields.removeAt(index);
    endRemoveRows();
    return true;
}

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The problem was caused here: beginInsertRows(parent, row, 0);
The third argument has to be row + count - 1.