QTimer does not fire (trigger) timeout - timeout

Question

I want to use Qtimer to pause executing of given block of codes, while in another thread it does something else. I connected the timeout of the thread with qeventloop quit, but the problem is, that the timeout is not called. When another emit occures, the timeout is magically triggered or if I add another connect the time out is triggered too. I think I miss something about the use of qtimer, qeventloop and qthread. Can anyone help? I extracted the basic code for testing and put it here:
main.cpp
#include "widget.h"
#include <QApplication>
#include "tim.h"
#include <QThread>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Widget *w=new Widget();
tim *t=new tim();
QThread *thread=new QThread();
t->moveToThread(thread);
thread->start();
QThread::connect(w,SIGNAL(signalDoIt()),t,SLOT(slotDoIt()),Qt::QueuedConnection);
QThread::connect(w,SIGNAL(signalQuitTimer()),t,SLOT(slotQuitTimer()),Qt::QueuedConnection);
QThread::connect(t,SIGNAL(signalSetText(QString)),w,SLOT(slotSetText(QString)),Qt::QueuedConnection);
w->show();
return a.exec();
}
tim.h
#ifndef TIM_H
#define TIM_H
#include <QObject>
#include<QTimer>
#include<QTime>
#include<QEventLoop>
#include<QThread>
#include<QDebug>
class tim : public QObject
{
Q_OBJECT
public:
tim();
~tim();
signals:
void signalSetText(QString);
public slots:
void slotDoIt();
void slotQuitTimer();
void slotShowTime();
private:
QTimer *trainingTimer;
QEventLoop loopTrainingWait;
QTime time;
};
#endif // TIM_H
tim.cpp
#include "tim.h"
tim::tim()
{
qDebug()<<"constructor";
trainingTimer=new QTimer(this);
trainingTimer->setTimerType(Qt::PreciseTimer);
trainingTimer->setSingleShot(true);
QThread::connect(trainingTimer,SIGNAL(timeout()),&loopTrainingWait,SLOT(quit()));
// QThread::connect(trainingTimer,SIGNAL(timeout()),this,SLOT(slotShowTime())); //to uncomment all works, but withou this, it does not
}
void tim::slotDoIt()
{
trainingTimer->start(5000);
time.start();
loopTrainingWait.exec();
QString text(QString::number(loopTrainingWait.isRunning())+" "+ QString::number(time.elapsed()));
qDebug()<<text;
emit signalSetText(text);
}
void tim::slotShowTime()
{
QString text(QString::number(loopTrainingWait.isRunning())+" slot "+ QString::number(time.elapsed()));
qDebug()<<text;
emit signalSetText(text);
}
void tim::slotQuitTimer()
{
if(loopTrainingWait.isRunning())
loopTrainingWait.quit();
if(trainingTimer->isActive())
trainingTimer->stop();
}
tim::~tim()
{
}
//gui for testing
widget.h
#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
namespace Ui {
class Widget;
}
class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = 0);
~Widget();
public slots:
void slotSetText(QString text);
signals:
void signalDoIt();
void signalQuitTimer();
private slots:
void on_pushButton_clicked();
void on_pushButton_2_clicked();
void on_pushButton_3_clicked();
private:
Ui::Widget *ui;
};
#endif // WIDGET_H
widget.cpp
#include "widget.h"
#include "ui_widget.h"
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
}
void Widget::slotSetText(QString text)
{
ui->label->setText(text);
}
Widget::~Widget()
{
delete ui;
}
void Widget::on_pushButton_clicked()
{
this->close();
}
void Widget::on_pushButton_2_clicked()
{
emit signalDoIt();
}
void Widget::on_pushButton_3_clicked()
{
emit signalQuitTimer();
}

Answer 1

I met the same issue,and eventually I wrote SLOT between public and :,then it works

Answer 2

the problem was in static qeventloop, making this dynamic
loopTrainingWait=new QEventLoop(this);
with parent this, resolved the issue