QSortFilterProxyModel is sorting only on based on string.

[Ayush Gupta]

I am have TreeView in my code. Basically I insert all the data as a string only in QTTreeView.
But some string are also number. So I need to sort those columns which are having number based on number sorting not on String sorting.

I have a limitataion in my code that I cannot use QVariant.

Is there any way I can write custom lessthan of QSortFilterProxyModel with which I can indentify which column is string and which column is number.

Is there any way I can tell the QTTreeView that this column contains number and this column contain string without using QVariant?

[sierdzio]

@Ayush-Gupta said in QSortFilterProxyModel is sorting only on based on string.:

Is there any way I can write custom lessthan of QSortFilterProxyModel with which I can indentify which column is string and which column is number.

Yes, check if QString converts to int without an error. If it does, you've got a number.

Is there any way I can tell the QTTreeView that this column contains number and this column contain string without using QVariant?

You can add a custom role to your model (you need to return it in data() method of your model) and check it in your filter proxy.

[Ayush Gupta]

@sierdzio said in QSortFilterProxyModel is sorting only on based on string.:

You can add a custom role to your model (you need to return it in data() method of your model) and check it in your filter proxy.

Can you expalin this further. How I can achieve this. May be a peice of code explaining this?

[sierdzio]

@Ayush-Gupta said in QSortFilterProxyModel is sorting only on based on string.:

@sierdzio said in QSortFilterProxyModel is sorting only on based on string.:

You can add a custom role to your model (you need to return it in data() method of your model) and check it in your filter proxy.

Can you expalin this further. How I can achieve this. May be a peice of code explaining this?

If you have a custom subclass for your model (do you?), you can do this:

// In some header
enum CustomRole {
  ColumnHasNumbers = Qt::UserRole + 1
}

// In model:
QVariant YourModelClass::data(const QModelIndex &index, int role) const
{
switch (role) {
case Qt::DisplayRole:
  // ...
case Qt::EditRole:
  // ...
case ColumnHasNumbers:
  // You need to detect which column has only numbers either here (inefficient) or somewhere else, for example during initialization of the model
  if (columnHasNumbers)
    return true;
  else
    return false;
}

[Ayush Gupta]

how can we return true or false? Seems data should return actual data column contains

[jsulm]

@Ayush-Gupta Boolean can be converted to QVariant: https://doc.qt.io/qt-5/qvariant.html#QVariant-8
So, the code should just work.

[sierdzio]

@Ayush-Gupta said in QSortFilterProxyModel is sorting only on based on string.:

how can we return true or false? Seems data should return actual data column contains

Look at other roles: https://doc.qt.io/qt-5/qt.html#ItemDataRole-enum there is far more information that can be (and is) returned than just column contents: you can specify the font, colours, size hints and custom roles.