QTimer advice

[qt_beginner]

Hi,

I'm a relative newbie to Qt but am so far enjoying it. I have a question about QTimer. I have it working in an application but am just wondering if I am going about it the correct way.

#include "timerExample.h"
#include <QtGui>
 
timerExample::timerExample(QWidget *parent, Qt::WFlags flags)
	: QWidget(parent, flags)
{
	ui.setupUi(this);
	time = 0;
	timeInterval = 1;	// this sets the time interval at 1 millisecond
	timer = new QTimer;
	connect(timer, SIGNAL(timeout()), this, SLOT(update()));
}
 
 
void timerExample::update()
{
	time = time + timeInterval;
}
 
 
void timerExample::on_threadStartButton_clicked()
{
	timer->start(timeInterval);
}
 
void timerExample::on_threadStopButton_clicked()
{
	timer->stop();
 
        // writes out time taken to a LineEdit
	QString str = QString::number(time);
	ui.timeLine->setText(str);
}

#include "timerExample.h"
#include <QtGui>

timerExample::timerExample(QWidget *parent, Qt::WFlags flags)
	: QWidget(parent, flags)
{
	ui.setupUi(this);
	time = 0;
	timeInterval = 1;	// this sets the time interval at 1 millisecond
	timer = new QTimer;
	connect(timer, SIGNAL(timeout()), this, SLOT(update()));
}


void timerExample::update()
{
	time = time + timeInterval;
}


void timerExample::on_threadStartButton_clicked()
{
	timer->start(timeInterval);
}

void timerExample::on_threadStopButton_clicked()
{
	timer->stop();

        // writes out time taken to a LineEdit
	QString str = QString::number(time);
	ui.timeLine->setText(str);
}

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Is this the right way to use QTimer or am I missing something?

[Lykurg]

Theoretical it's ok, but in your case nonsens, and 1 millisecond is normally too short (a function call every millisecond...). In your case better have a look at QTime and QTime::elapsed().

[qt_beginner]

Thanks for your input. I see that that function is exactly what I need but I'm using Qt 4.4. I can't see a similar method to that described in this version.

[Lykurg]

Well, it must be there: http://doc.trolltech.com/4.3/qtime.html#elapsed. But anyway, then do it yourself. On first button take the value of QTime::currentTime() and on the second button also and then calculate the difference between both.