How to get the status of hardcoded QCheckBoxes in QSqlQueryModel? - c++

Question

I have a QTableView that shows QSqlQueryModel. The model contains checkboxes that are created in each row in the first column (which contain the ref_no; the primary-key in my db) as follow:
void MainWindow::showM(model){
ui->tableView->setModel(model);
ui->tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
for( int i = 0; p<model->rowCount(); i++)
{
QCheckBox *checkBox = new QCheckBox();
ui->tableView->setIndexWidget(model->index(i,0),checkBox);
}
ui->tableView->show();
}
... and it's working fine, displaying all the information I need plus the checkboxes.
Now, I need to get the ref_no where the adjacent checkbox is checked.
How to do that ?

Answer 1

Use QSignalMapper (or an ad hoc solution involving a mapper using sender(), or lambdas). For instance define a member for the mapping:
QHash<QCheckBox *, int> m_mapping;
Then in your code hook it up like this:
QCheckBox *checkBox = new QCheckBox();
ui->tableView->setIndexWidget(model->index(i,0),checkBox);
m_mapping[checkBox] = i;
connect(checkBox, &QCheckBox::toggled, this, &MainWindow::onCheckBoxToggled);
Then define a slot like this:
// for the love of kittens use proper names for methods
void MyWindow::onCheckBoxToggled(bool toggled) {
QCheckBox *box = static_cast<QCheckBox *>(sender());
const int id = m_mapping.value(box);
// do something
}
Or, if you fancy lambdas, you can do the above with a capture:
connect(checkBox, &QCheckBox::toggled,
[i](bool toggled){ /* use i, toggled */ });
All of that having being said, I would strongly recommend against the idea of creating QCheckBoxes and using setIndexWidget. Instead, employ a proxy model that enriches your column by returning the Qt::ItemIsUserCheckable flag and handles reads and writes for the Qt::CheckStateRole.