signal interval question

clementNg

I want to change my signal to change value in an interval.
For example, I want to update the valueSpinBox when i have changed the horizontalSliders.

connect(horizontalSliders, &SlidersGroup::valueChanged, [=](int value){
   this->ui->valueSpinBox->setValue(value);
});

However, I want to change the value in an interval 200ms intead of changing them real time. Is it possible? Thank you.

jsulm

@clementNg You will need to use QTimer
For example, if you want to do the actual change 200ms after signal was emitted you can use https://doc.qt.io/qt-5/qtimer.html#singleShot

clementNg

@jsulm
Thank you for your reply. Do I need to disconnect the signal and connect again after the interval? Would you mind to give a simple example? Thanks.

QTimer::singleShot(200, [=](){
// connect my horizontalSliders slot here?
// disconnect the slot after the action?
});

jsulm

@clementNg

connect(horizontalSliders, &SlidersGroup::valueChanged, [=](int value){
    QTimer::singleShot(200, [=](){
        this->ui->valueSpinBox->setValue(value);
    });
});

No need to disconnect as singleShot does not connect anything.