[SOLVED] Execute code every X seconds (X not constant)

[BlackMamba]

Hello,

I have a vector which contains some time values like 0, 1.34, 4.56, etc ... which are not regular.
I want to be able to execute some code for all these time values.
The first idea I had was to use a QTimer but how? Because QTimer looks more useful when you need to execute code every fixed time interval with timeout() signal.

Thanks for your help,

[raven-worx]

is "QTimer::singleShot()":http://qt-project.org/doc/qt-4.8/qtimer.html#singleShot what you are looking for?

[BlackMamba]

If I use a QTimer, yes it will need to be singleshot but it is not enough to solve my issue.
Lets say I do timer->start();
Then how do I parse my vector in real time to know if I need to execute the code?
@QTimer* timer = new QTimer;
timer->setSingleShot(true);
timer->start();
for(int i=0;i<myvector.size();i++){
if(timer->ellapsed()=myvector[i]{
// execute code
}
}@

This looks to be very awkward and I dont know if the "=" in
@if(timer->ellapsed()=myvector[i] @

is working ...

[raven-worx]

QTimer::singelShot() is a static method. So you don't need a QTimer instance and thus also not call start().
The slot you specify will be executed once on timeout.

[BlackMamba]

Yes but how does this solve my issue?
I would like to have kind of timeout but at irregular interval ...

[raven-worx]

for example:
@
void MyExecuteSlot()
{
//DO SOME WORK

if( values.count() )   //values is of type QList?
    QTimer::singleShot( values.takeFirst() * 1000, this, SLOT(MyExecuteSlot()) );

}
@

I assumed your values are in seconds? (QTimer only accepts milliseconds).

Please note: I don't know on which OS you are working on, but you will only receive an approximate real time speed on a non realtime OS.

[BlackMamba]

It looks nice I will try this tonight . I am working on windows. I don't need real time OS, how accurate this timer will be? If the latence is like 10ms, its fine !
I have a std::vector instead of a QList but you gave me the logic !
I knew the ravens were very smart ;)

Thanks

[mehrdadsilver]

and you can use setTimerType(Qt::PreciseTimer) for better accuracy if you want to use QTimer object (No Static singleshot). after each interval restart timer with next value.

[NicuPopescu]

good to know you're working on windows ... so you could have a time resolution of nanoseconds ... and I think in this case qint64 QElapsedTimer::nsecsElapsed () const could be used

bq. if(timer->ellapsed()=myvector[i]{
// execute code
}
}

QTimer even has no ellapsed method

on the other hand, I think QTimerEvent or QBasicTimer are lighter/faster than QTimer using signals; anyway all of them provide control just in milliseconds, compared with QElapsedTimer which can work with much higher resolution

see also QElapsedTimer::ClockType for windows

Cheers!