Solved How to properly create a two way connection with QComboBox?

[lansing]

I have a main window with a QTabWidget. The main window also has a child dialog widget with a QcomboBox. The name of the tab in the tabwidget will be the selections of the qcombobox. The QTabWidget and the QComboBox were created in their corresponded ui files.

What I want now is that when I switched tab in the main window, I want the selection in the qcombobox to also be changed, matching the tab index. And vise versa when I changed selection in qcombobox, I want the tab to also be changed.

My signal connection now works only one way going from qcombobox to qtabwidget. When I tried to connect them the other way around I was getting into an infinite loop that I don't know how to get out.

main window.cpp

// somewhere on top
m_pMyDialog = new MyDialog(this);

connect(m_pMyDialog, &MyDialog::signalComboBoxChanged,
            this, &MainWindow::slotSetComboBox);

connect(m_ui->tabWidget, &QTabWidget::currentChanged,
            this, &MainWindow::slotChangeTab);


void MainWindow::slotChangeTab(int a_index) 
{
    // some logic
    m_pMyDialog->slotUpdateSelection(a_index);
}

void MainWindow::slotSetComboBox(int a_index)
{
   // some logic to talk to combobox in mydiag.cpp   
    m_pMyDialog->slotSetSomeValue(some value);

    m_ui->tabWidget->setCurrentIndex(a_index);
}

mydialog.cpp

connect(ui->selectComboBox, QOverload<int>::of(&QComboBox::currentIndexChanged), 
    this, MyDialog::signalComboBoxChanged);


void MyDialog::slotUpdateSelection(int a_index) 
{
    if (ui->selectComboBox->currentIndex() != a_index)    
        ui->selectComboBox->setCurrentIndex(a_index);
}

I can make a function in mydialog.cpp to update combobox selection and called it in slotChangeTab, but that will get me into an infinite loop. What is the proper way to do this?

[Christian Ehrlicher]

Simply check if the current index in the QComboBox is the selected one and if then don't call setCurrentIndex()

[lansing]

@Christian-Ehrlicher

Where do I start calling when going from tab Change to QcomboBox change?

[Christian Ehrlicher]

@lansing said in How to properly create a two way connection with QComboBox?:

Where do I start calling when going from tab Change to QcomboBox change?

I do not understand what you mean.

[SGaist]

Hi,

You can do that at the top of each slot.

[lansing]

@SGaist

Thanks I got it working, I don't know why it works but I'll take it. I updated the first post for future reference.