Disable QSlider's valueChanged on keyboard arrow keys

Question

How can I disable QSlider's emitting SIGNAL valueChanged on keyboard arrows and mouseWheel scroll. By setting

    ui->horizontalSlider->setFocusPolicy(Qt::NoFocus);

the keyboards arrows keys are not emitting signals.

How can I do the same for mouse wheel scroll? I don't want to reimplement my custom Slider class from QSlider. Am asking for any work around or api, so that I can disable the keyboard and mouse wheel scroll responding to qslider.

The main intention is to avoid sending signals on every valueChange. So I have implemented the following and it's working fine

on_horizontalSlider_sliderReleased()
on_horizontalSlider_sliderPressed()

based on bool flag updated in these 2 slots,

on_horizontalSlider_valueChanged(int)

is doing the required operation...like after slider released, value is being added in the required application.

Request to provide approaches, examples for the work around.

Answer 1

class CBlockWheelEV: public QObject
{
    Q_OBJECT
public:
    CBlockWheelEV( QObject* parent ): QObject( parent ) {}
    bool eventFilter(QObject * pObject, QEvent * pEvent) override
    {
        if ( pEvent->type() == QEvent::Wheel )
        {
            qDebug() << pObject << pEvent;
            return true; // if return false - Scroll was unlocking
        }
        return false;
    }
};

...
ui->sldTest->installEventFilter( new CBlockWheelEV( ui->sldTest ) );
...

You can use EventFilter to block emitting signals ValueChanged from QSlider by wheel rotating. But if you want some special behavior - you need control additional options in you EventFilter. EventFilter can manage many behavior of object without subclassing it.