Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

How to call a function after every 15 seconds using QT

Tags:

c++

qt

I know my question is similar to this QUESTION but i cant find solution from there. Can anyone give a breif answer to my problem?

I have a function like this

void myWidget::showGPS()
{

/* This function will read data from text file
      that will continuouly change over time
           then process its data */

}

I want to call this function every 15-20 seconds without using Quick-and-dirty method of setting boolean to true .

Is there any way to implement this using QT signal and slot with timer or something like that

like image 628
Bavani Avatar asked Oct 10 '13 05:10

Bavani


People also ask

How do you set a timer on QT?

You can set a timer to time out only once by calling setSingleShot(true). You can also use the static QTimer::singleShot() function to call a slot after a specified interval: QTimer::singleShot(200, this, &Foo::updateCaption); In multithreaded applications, you can use QTimer in any thread that has an event loop.


1 Answers

The method showGPS(), should be made a slot of MyWidget class. Then on, its just a matter of using the QTimer class.

 QTimer *timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), myWidget, SLOT(showGPS()));
    timer->start(15000); //time specified in ms

The above code will call showGPS(), every 15 seconds. Since the call is periodic, you don't have to set the timer in one shot mode using the setSingleShot() method.

Edit:

This is a simple poc, to help you understand it..

#include <QApplication>
#include <QtGui>
#include <qobject.h>

class MyWidget : public QWidget
{
    Q_OBJECT

public:
    MyWidget()
    {
        timer = new QTimer(this);
        QObject::connect(timer, SIGNAL(timeout()), this, SLOT(showGPS()));
        timer->start(1000); //time specified in ms
    }

public slots:
    void showGPS()
    {
        qDebug()<<Q_FUNC_INFO;
    }

private:
    QTimer *timer;
};


int main(int argc, char **args)
 {
    QApplication app(argc,args);
    MyWidget myWidget;


    return app.exec();
}
like image 107
Barath Ravikumar Avatar answered Oct 26 '22 04:10

Barath Ravikumar