Retrieving the row number of a QTableView - c++

Question

I'm using a QTableView to display some data inside a table. Because no vertical header is given Qt automatically assigns a row-id to a row. The example below displays the following table:
id|data
-------
1 | B
2 | A
3 | D
4 | C
After sorting the table based on the "data"-column:
id|data
-------
2 | A
1 | B
4 | C
3 | D
When a user double-clicks an entry, I want to be able to identify the clicked row by its id (i.e. A=2, B=1, C=4, D=3). Unfortunately, the methods used in "onDoubleClicked" only return the "new" row-id (i.e. A=1, B=2, C=3, D=4).
So how do I retrieve the correct row-id, when a user doubleclicks a row?
table.h
#ifndef TABLE_H
#define TABLE_H
#include <QTableView>
#include <QModelIndex>
#include <QHeaderView>
#include <QDebug>
class Table : public QTableView {
Q_OBJECT
public:
explicit Table() : QTableView() {
setSortingEnabled(true);
connect(this, &Table::doubleClicked, this, &Table::onDoubleClicked);
}
public slots:
void onDoubleClicked(QModelIndex index) {
qDebug() << index.row();
qDebug() << verticalHeader()->logicalIndex(index.row());
qDebug() << verticalHeader()->logicalIndexAt(index.row());
qDebug() << verticalHeader()->visualIndex(index.row());
qDebug() << verticalHeader()->visualIndexAt(index.row());
}
};
#endif // TABLE_H
main.cpp
#include <QApplication>
#include <QStandardItemModel>
#include <QSortFilterProxyModel>
#include "table.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Table table;
QStandardItemModel model;
QList<QStandardItem*> items;
items.append(new QStandardItem("B"));
items.append(new QStandardItem("A"));
items.append(new QStandardItem("D"));
items.append(new QStandardItem("C"));
model.appendColumn(items);
QSortFilterProxyModel proxy;
proxy.setSourceModel(&model);
proxy.sort(0, Qt::AscendingOrder);
table.setModel(&proxy);
table.show();
return a.exec();
}

Answer 1

The model is not having a new row(), you forgot that you are passing them via a proxy model. A proxy model holds different rows() and columns() from the original model because it can rearrange or filter fields.
The fix is easy - you just need to map the index from the proxy model to the original one.
void onDoubleClicked(QModelIndex index) {
QSortFilterProxyModel *m = qobject_cast<QSortFilterProxyModel*>(model());
auto sourceIdx = m->mapToSource(index);
qDebug() << sourceIdx.row();
qDebug() << verticalHeader()->logicalIndex(sourceIdx.row());
qDebug() << verticalHeader()->logicalIndexAt(sourceIdx.row());
qDebug() << verticalHeader()->visualIndex(sourceIdx.row());
qDebug() << verticalHeader()->visualIndexAt(sourceIdx.row());
}

Answer 2

These work for me.
void DeviceData::doubleClicked(QModelIndex cell)
{
cell.column();
cell.row();
}
Which you can then feed into your model: model.at(cell.row()).
Or you create a find() function.

Answer 3

if the value is bind with A you can use the setData method provided by QTableWidgetItem.set the value and get the value back by a specific flag.maybe Qt::UserRole
EDIT:
base on your code.
items.append(new QStandardItem("B"));
then you can get the QStandardItem make the item.setData(1,Qt::UserRole) while 1 is the value which is bind to "B".Later you can get the bind value from item.data(Qt::UserRole).Note: it would return a variant then you need to transfer it toInt