Does QTimer resuse unique id? - qt

Question

I looked in the documentation and I didn't find something about reusing unique Id.
The documentation says about the startTimer function:
The function returns a unique integer timer ID
But how long will it be unique? Does it reuse the ids at some point?

Answer 1

But how long will it be unique?
The timer ID should remain unique until it is released via QAbstractEventDispatcherPrivate::releaseTimerId();
In other words, calling killTimer().
Does it reuse the ids at some point?
I quickly wrote a simple test to see if the timer ID would get reused:
Something.h:
#include <QCoreApplication>
#include <QtCore>
#include <QtGlobal>
class Something : public QObject
{
Q_OBJECT
public:
Something() : QObject() {}
~Something() {}
};
main.cpp:
#include "Something.h"
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
Something thing;
int i = thing.startTimer(1000);
qDebug() << i;
thing.killTimer(i);
i = thing.startTimer(1000);
qDebug() << i;
return a.exec();
}
The result:
1
1
Finally, using QTimer exclusively... you can test with:
class Something : public QObject
{
Q_OBJECT
public:
Something() : QObject(), timer(NULL) {}
~Something() {}
void runme()
{
timer = new QTimer();
// Old school ;)
QObject::connect(timer, SIGNAL(timeout()), this, SLOT(timerEvent()));
timer->start(100);
}
public Q_SLOTS:
void timerEvent()
{
qDebug() << timer->timerId();
timer->stop();
delete timer;
timer = new QTimer();
QObject::connect(timer, SIGNAL(timeout()), this, SLOT(timerEvent()));
timer->start(1000);
}
public:
QTimer* timer;
};
Then just kick it off and run it:
Something thing;
thing.runme();