QDialog return value, Accepted or Rejected only?

Question

How to return custom value from a QDialog ? It's documented it returns

QDialog::Accepted   1
QDialog::Rejected   0

respectively if user press Ok of Cancel .

I'm thinking in a custom dialog presenting ie three check boxes to allow user to select some options. Would QDialog be appropriate for this?

Answer 1

You'll be interested in 2 functions:

• QDialog::setResult() lets you use any integer as a return value (without closing the dialog): http://doc.qt.io/qt-5/qdialog.html#setResult .
• QDialog::done() does the same, except that it closes the dialog and makes QDialog::exec() return the result you specified: http://doc.qt.io/qt-5/qdialog.html#done

Usually, the "OK" button in a QDialog is connected to the QDialog::accept() slot. You want to avoid this. Instead, write your own handler to set the return value:

// Custom dialog's constructor
MyDialog::MyDialog(QWidget *parent = nullptr) : QDialog(parent)
{
    // Initialize member variable widgets
    m_okButton = new QPushButton("OK", this);
    m_checkBox1 = new QCheckBox("Option 1", this);
    m_checkBox2 = new QCheckBox("Option 2", this);
    m_checkBox3 = new QCheckBox("Option 3", this);

    // Connect your "OK" button to your custom signal handler
    connect(m_okButton, &QPushButton::clicked, [=]
    {
        int result = 0;
        if (m_checkBox1->isChecked()) {
            // Update result
        }

        // Test other checkboxes and update the result accordingly
        // ...

        // The following line closes the dialog and sets its return value
        this->done(result);            
    });

    // ...
}