Button-Controlled Loop

[freekill]

Hi. I've encountered trouble fixing my code since last night. It's just a simple program that has an infinite loop and I'm trying to modify the bool sentinel using buttons. I don't know what I'm missing because I keep getting errors on build. I hope you can help me out.

[Lykurg]

Once you start the loop, the Gui isn't accessible so you couldn't stop the loop. Two solutions: use QCoreApplication::processEvents() or use a thread for the loop. You also can read this article.

[freekill]

I was working on some other things I left out this part of my program. Anyway, I'm not familiar with the processEvents() can you help me out in a little more detail? Where and how do I implement this? I ended up with this--a lot of errors in my looper.cpp

#include <QtGui> 
#include "looper.h"
 
bool stop;
void mainLoop();
 
basicLoop::basicLoop(QWidget *parent)
{
     setupUi(this); // this sets up GUI
 
     connect( startButton, SIGNAL( clicked() ), this, SLOT( startLoop() ) );
     connect( stopButton, SIGNAL( clicked() ), this, SLOT( stopLoop() ) );
}
 
void basicLoop::startLoop()
{
     &stop = false;
     mainLoop();
}
 
void basicLoop::stopLoop()
{
     &stop = true;
}
 
void mainLoop()
{
     int i=0;
     //check for stop button press
     QCoreApplication::processEvents();
     if (stopButton->isChecked) stopLoop();
     while(!&stop)
     {
         textEdit->append(QString::number(i));
         i++;
     }
}

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

bool stop;
void mainLoop();

basicLoop::basicLoop(QWidget *parent)
{
     setupUi(this); // this sets up GUI
 
     connect( startButton, SIGNAL( clicked() ), this, SLOT( startLoop() ) );
     connect( stopButton, SIGNAL( clicked() ), this, SLOT( stopLoop() ) );
}
 
void basicLoop::startLoop()
{
     &stop = false;
     mainLoop();
}

void basicLoop::stopLoop()
{
     &stop = true;
}

void mainLoop()
{
     int i=0;
     //check for stop button press
     QCoreApplication::processEvents();
     if (stopButton->isChecked) stopLoop();
     while(!&stop)
     {
         textEdit->append(QString::number(i));
         i++;
     }
}

To copy to clipboard, switch view to plain text mode 

I'm not sure if this is making sense..I don't know how to connect my stopButton now and how I would call the function stopLoop..

[nish]

this is how its done.

void mainLoop()
{
     int i=0;
     //check for stop button press
     //QCoreApplication::processEvents();//Put this inside loop
     //if (stopButton->isChecked) stopLoop();//no need for this
     while(!&stop)
     {
         QCoreApplication::processEvents();
         textEdit->append(QString::number(i));
         i++;
     }
}

void mainLoop()
{
     int i=0;
     //check for stop button press
     //QCoreApplication::processEvents();//Put this inside loop
     //if (stopButton->isChecked) stopLoop();//no need for this
     while(!&stop)
     {
         QCoreApplication::processEvents();
         textEdit->append(QString::number(i));
         i++;
     }
}

To copy to clipboard, switch view to plain text mode 

[freekill]

thanks for that..I'm gettin close
just a minor problem here though..I couldn't access the textEdit object since my function mainLoop is not part of the widget basicLoop..how do I access to textEdit?

[nish]

make a static function in your class which will return the textedit pointer.

btw, this question belongs to the newbie/C++ section