[Qt-interest] EditableTreeMode example crashing with modeltest

[Daniel Price]

> I suppose because if the column is > 0 it usually should not have a
> parent (and therefore has no valid index) - only a sibling in column 0.

My understanding is that each column is represented by a separate QModelIndex, accessible through the sibling() member function. But each column index must have the same parent otherwise how would QAbstractItemModel::index(row, column, parent) et al work?

> Maybe make sure you provide as much item data as you have columns
> (headers) in the root item

>   QVector<QVariant> rootData;
>      foreach (QString header, headers)
>          rootData << header;

Yes I have done this. If I don't have data, I just get empty columns which I can edit.

The assert is being triggered because the unit test is asking for the non-zero column-index of a valid row.

I'm not sure if this is the cause of my original issue (inconsistency between the view and the model) but there is something very wrong here!

Here is my adaptor in it's entirety (TreeNode is very similar to Qt's TreeItem):

TreeModelAdaptor::TreeModelAdaptor(const QStringList &headers, QObject *parent)
        :
        QAbstractItemModel(parent),
        m_rootNode(NULL)
{
        QVector<QVariant> rootData;
        foreach (QString header, headers)
                rootData << header;

        m_rootNode = new TreeNode(rootData);
}

TreeModelAdaptor::~TreeModelAdaptor()
{
        delete m_rootNode;
}

QModelIndex TreeModelAdaptor::index(int row, int column, const QModelIndex &parent) const
{
        if (parent.isValid() && parent.column() != 0)
                return QModelIndex();

        if (row < 0 || column < 0)
                return QModelIndex();

        TreeNode *parentNode = nodeFromIndex(parent);

        TreeNode *childNode = parentNode->child(row);
        if (childNode)
                return createIndex(row, column, childNode);
        else
                return QModelIndex();
}

QModelIndex TreeModelAdaptor::parent(const QModelIndex &index) const
{
        if (!index.isValid())
                return QModelIndex();

        TreeNode *childNode = nodeFromIndex(index);
        TreeNode *parentNode = childNode->parent();

        if (parentNode == m_rootNode)
                return QModelIndex();

        return createIndex(parentNode->childNumber(), 0, parentNode);
}

int TreeModelAdaptor::rowCount(const QModelIndex &parent) const
{
        TreeNode *parentNode = nodeFromIndex(parent);

        return parentNode->childCount();
}

int TreeModelAdaptor::columnCount(const QModelIndex &parent) const
{
        return m_rootNode->columnCount();
}

QVariant TreeModelAdaptor::headerData(int section, Qt::Orientation orientation, int role) const
{
        if (orientation == Qt::Horizontal && role == Qt::DisplayRole)
                return m_rootNode->data(section);

        return QVariant();
}

Qt::ItemFlags TreeModelAdaptor::flags(const QModelIndex &index) const
{
        if (!index.isValid())
                return 0;

        return Qt::ItemIsEditable | Qt::ItemIsEnabled | Qt::ItemIsSelectable;
}

QVariant TreeModelAdaptor::data(const QModelIndex &index, int role) const
{
        if (!index.isValid())
                return QVariant();

        if (role != Qt::DisplayRole && role != Qt::EditRole)
                return QVariant();

        TreeNode *node = nodeFromIndex(index);

        return node->data(index.column());
}

bool TreeModelAdaptor::setData(const QModelIndex &index, const QVariant &value, int role)
{
        if (role != Qt::EditRole)
                return false;

        TreeNode *node = nodeFromIndex(index);
        bool result = node->setData(index.column(), value);

        if (result)
                emit dataChanged(index, index);

        return result;
}

bool TreeModelAdaptor::insertColumns(int position, int columns, const QModelIndex &parent)
{
        beginInsertColumns(parent, position, position + columns - 1);
                bool success = m_rootNode->insertColumns(position, columns);
        endInsertColumns();

        return success;
}

bool TreeModelAdaptor::removeColumns(int position, int columns, const QModelIndex &parent)
{
        beginRemoveColumns(parent, position, position + columns - 1);
                bool success = m_rootNode->removeColumns(position, columns);
        endRemoveColumns();

        if (m_rootNode->columnCount() == 0)
                removeRows(0, rowCount());

        return success;
}

bool TreeModelAdaptor::insertRows(int position, int rows, const QModelIndex &parent)
{
        TreeNode *parentNode = nodeFromIndex(parent);

        beginInsertRows(parent, position, position + rows - 1);
                bool success = parentNode->insertChildren(position, rows, m_rootNode->columnCount());
        endInsertRows();

        return success;
}

bool TreeModelAdaptor::removeRows(int position, int rows, const QModelIndex &parent)
{
        TreeNode *parentNode = nodeFromIndex(parent);

        beginRemoveRows(parent, position, position + rows - 1);
                bool success = parentNode->removeChildren(position, rows);
        endRemoveRows();

        return success;
}

TreeNode* TreeModelAdaptor::nodeFromIndex(const QModelIndex &index) const
{
        if (index.isValid())
        {
                TreeNode *item = static_cast<TreeNode*>(index.internalPointer());
                if (item)
                        return item;
        }
        return m_rootNode;
}


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