Holding Program until QWidget is closeed

[FreddyKay]

Hey Guys!

I am using a QWidget for collecting User Input. Now at a certain point I want the program to wait until the QWidget is closed before continuing. In contrast to the QDialog class the QWidget class does not offer an exec() method. Is there another way I can achieve the "waiting" behaviour?

[anda_skoa]

Event loop driven programs are always "running", exec() only makes it look like it is not "stopping" at some point.

Instead of writing code "sychronously", e.g. like this

// to one thing
 
dialog.exec();
 
// do anoher thing

// to one thing

dialog.exec();

// do anoher thing

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you can always split the two parts into two methods and let the second part be triggered by a signal, e.g. like this

void MyClass::method1()
{
  // to one thing
}
 
void MyClass::method2()
{
  // to another thing
}

void MyClass::method1()
{
  // to one thing
}

void MyClass::method2()
{
  // to another thing
}

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The trigger for the execution of the slot method2() is then a signal from the input widget, that it emits when it is satisfied with the input.

Cheers,
_

[FreddyKay]

First of all, thank you for your suggestion! I also thought of that workaround, I just wondered whether there is another, more elegant way of recreating "exec()" possibly using some Qt methods I wasn't aware of. Anyway thanks alot!

[anda_skoa]

You can do the same thing QDialog is doing internally, i.e. using a nested event loop.

QEventLoop loop;
connect(myWidget, SIGNAL(mySignal()), &loop, SLOT(quit()));
loop.exec();

QEventLoop loop;
connect(myWidget, SIGNAL(mySignal()), &loop, SLOT(quit()));
loop.exec();

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As with QDialog::exec() be aware that this just moving event processing, not halting it.

In most cases it is safer to go for an asynchronous approach instead of pseudo-synchronous.
So what you consider a work around now is actually the more elegant solution

Cheers,
_

[FreddyKay]

This seems to be what I was looking for. I will give it a try, though its not as straightforward as the first approach, it might actually save me a bit of work Thanks again!