How to get DisplayRole?

[SRaD]

I have a delegate for my TreeView with a paint method like the following, but the problem is that when the mouse hovers over a row, index_data is always empty showing "".

void MyTreeViewDelegate::paint(QPainter *painter,
const QStyleOptionViewItem &option, const QModelIndex &index) const
{
    QModelIndex parent = index.parent();
    QModelIndex child = index.sibling(parent.row(), parent.column());

    QString index_data = index.data(Qt::DisplayRole).toString();

    if (option.state & QStyle::State_MouseOver) {
        std::cout << "got a mouse over" << std::endl;                         

    qDebug() << "index_data: " << index_data;
    }           
    // ...
}

Any thoughts where I'm going wrong?

[mrjj]

Hi
the same code works fine with a QStandardItemModel

so my guess is that you use a custom model and there is something with the index or it
uses EditRole and not Display role.

[SRaD]

I do use a custom model. I'm hoping the following helps in some way.

QVariant MyTreeModel::data(const QModelIndex &index, int role) const
{
    QModelIndex parent = index.parent();
    QModelIndex child = index.sibling(parent.row(), parent.column());

    if (!index.isValid())
        return QVariant();

    MyTreeItem *item = static_cast<MyTreeItem *>
        (index.internalPointer());

    if (role == Qt::CheckStateRole) {
        if (parent.row() == 0 && index.column() == 0)
            return static_cast<int>(item->getChecked() ? Qt::Checked :
            Qt::Unchecked);
    }

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

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

[mrjj]

Hi
Try to qDebug() << index in delegate and
then call
MyTreeModel::data with same index and see if it returns anything valid.

also did you reuse the model from here ?
https://doc.qt.io/qt-5/qtwidgets-itemviews-simpletreemodel-example.html