How to update displayed row number after dragdrop in QTableView

JohnGa

Hello,
I successfully enabled the ability to move rows within a QTableView. I also have the row numbers display (In the row headers) enabled. The following are my settings:
```
qTableView->verticalHeader()->setSectionsMovable(true);
qTableView->verticalHeader()->setDragEnabled(true);
qTableView->verticalHeader()->setDragDropMode(QAbstractItemView::InternalMove);

Let's say I start out with rows (row contents in braces): 
Row #1 -> (A), Row #2  -> (B), Row #3 -> (C).

I grab and move row 1, to after row 3.

The view now shows the following:
Row #2  -> (B), Row #3 -> (C), Row #1 -> (A),

How can I update and reassign the row numbers in the view?  After the item has been dropped I want it to show:
Row #1 -> (B), Row #2  -> (C), Row #3 -> (A)

Thanks.

SGaist

Hi,

What model do you have underneath ?

In any case, you likely want to re-implement the model's headerData method.

JohnGa

I have my own implementation of the model. It is subclassed off of QAbstractTableModel. I have already re-implemented the headerData method.

In the headerData method, I currently have the following code to display the row numbers:

    if(orientation == Qt::Vertical)
    {
        return QString::number(section + 1);
    }

Can you please give me a hint on what I need to do in the headerData method?

SGaist

Ok... It's a bit more tricky than that as it seems.

Use this custom QHeaderView class:

class HeaderView : public QHeaderView
{
public:

    HeaderView(Qt::Orientation orientation, QWidget *parent = nullptr)
    : QHeaderView(orientation, parent)
    {}


void paintSection(QPainter *painter, const QRect &rect, int logicalIndex) const override
{
    QHeaderView::paintSection(painter, rect, visualIndex(logicalIndex));
}

};

JohnGa

SGaist,
You are truly amazing. I was able to get it to work with this.

One last tip request: After the drop has finished I want to take the moved row, access it's details and do further processing. How can I accomplish this?

Thanks.

SGaist

You can re-implement dropMimeData and launch the processing from there.