Question

Suppose there are checkboxes, options etc controls in a dialog box, how could I save the state of the dialog in Qt?

Should I use QSettings or something else?

Thanks.

Answer 1

I ran into the same problem.
Googling didn’t help too much.
So in the end I wrote my own solution.

I’ve created a set of functions that read and write the state of each child control of a dialog at creation respectively destruction.
It is generic and can be used for any dialog.

It works like this:

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    QMoMSettings::readSettings(this);
}

Dialog::~Dialog()
{
    QMoMSettings::writeSettings(this);
    delete ui;
}

...

void QMoMSettings::readSettings(QWidget* window)
{
    QSettings settings;

    settings.beginGroup(window->objectName());
    QVariant value = settings.value("pos");
    if (!value.isNull())
    {
        window->move(settings.value("pos").toPoint());
        window->resize(settings.value("size").toSize());
        recurseRead(settings, window);
    }
    settings.endGroup();
}

void QMoMSettings::writeSettings(QWidget* window)
{
    QSettings settings;

    settings.beginGroup(window->objectName());
    settings.setValue("pos", window->pos());
    settings.setValue("size", window->size());
    recurseWrite(settings, window);
    settings.endGroup();
}

void QMoMSettings::recurseRead(QSettings& settings, QObject* object)
{
    QCheckBox* checkbox = dynamic_cast<QCheckBox*>(object);
    if (0 != checkbox)
    {
        checkbox->setChecked(settings.value(checkbox->objectName()).toBool());
    }
    QComboBox* combobox = dynamic_cast<QComboBox*>(object);
    if (0 != combobox)
    {
        combobox->setCurrentIndex(settings.value(combobox->objectName()).toInt());
    }
    ...

    foreach(QObject* child, object->children())
    {
        recurseRead(settings, child);
    }
}

void QMoMSettings::recurseWrite(QSettings& settings, QObject* object)
{
    QCheckBox* checkbox = dynamic_cast<QCheckBox*>(object);
    if (0 != checkbox)
    {
        settings.setValue(checkbox->objectName(), checkbox->isChecked());
    }
    QComboBox* combobox = dynamic_cast<QComboBox*>(object);
    if (0 != combobox)
    {
        settings.setValue(combobox->objectName(), combobox->currentIndex());
    }
    ...

    foreach(QObject* child, object->children())
    {
        recurseWrite(settings, child);
    }
}

Hope this helps someone after me.