Exit unending loop with Button

[Roelof]

Good day.

I have created a GUI that uses its buttons to change different states of a system. I want to be able to run a unending loop that reads data over the PCI bus inside of each event of a button. I have the buttons and I have the functions that run the unending loop that reads the PCI bus.
However, when the loop is running inside the event of the button I loose functionality of the gui.

So I basicly want to learn how to run a unending loop in the event of a button and still be able to control the GUI

I will try to explain with code:

void Controller::standby()
{	
               powerDownButton->setEnabled(true);
               standbyButton->setEnabled(false);
 
                int val = 1;
                while (val == 1)
                     {
                            read_data();
 
                         //here I nead something to exit the loop when a button is pressed;
                         //something that I can use to change val to another value and exit the loop
                        }

void Controller::standby()
{	
               powerDownButton->setEnabled(true);
               standbyButton->setEnabled(false);
              
                int val = 1;
                while (val == 1)
                     {
                            read_data();
                         
                         //here I nead something to exit the loop when a button is pressed;
                         //something that I can use to change val to another value and exit the loop
                        }

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Hope this post makes sense.
Thanks to anyone that can help!

[elmo]

You have to create a new thread (with QThread) and place in it this unending loop.
See also this.

[Lykurg]

or you use QCoreApplication::processEvents(). something like this:

void Controller::on_powerDownButton_clicked()
{
  m_buttonPressed = true;
}
 
void Controller::standby()
{   
  powerDownButton->setEnabled(true);
  standbyButton->setEnabled(false);
  int val = 1;
  m_buttonPressed = false; // member variable!
  while (val == 1)
  {
    read_data();
    QCoreApplication::processEvents();
    if (m_buttonPressed)
    {
      //do your stuff here...
    }
  }
}

void Controller::on_powerDownButton_clicked()
{
  m_buttonPressed = true;
}

void Controller::standby()
{   
  powerDownButton->setEnabled(true);
  standbyButton->setEnabled(false);
  int val = 1;
  m_buttonPressed = false; // member variable!
  while (val == 1)
  {
    read_data();
    QCoreApplication::processEvents();
    if (m_buttonPressed)
    {
      //do your stuff here...
    }
  }
}

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depends on your task what is better. This or a separate thread.

[Roelof]

Thanx Lykurg!!!!

I was afraid I had to do mutlithreading, but this is the solution I was looking for.

I appreciate the help!