Closing program when widget is closed.

I have a program which instantiates and uses another class (subclass of Qwidget) . When I closed the widget, program does not terminate, how can I also terminate main function?

Quote:

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Originally Posted by metdos

how can I also terminate main function?

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You never need to terminate main function.

In main program, I have a infinite loop, and I need to stop infinite loop when widget is closed by user.

Quote:

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Originally Posted by metdos

I have a program which instantiates and uses another class (subclass of Qwidget) . When I closed the widget, program does not terminate, how can I also terminate main function?

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means u want to terminate the whole application ...
use qApp->quit();

But, how will understand that widget is closed? I put qApp->quit(); to destructor of QT class, but it didn't work.

usually this line

Code:

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...
QObject::connect( qApp, SIGNAL(lastWindowClosed()), qApp, SLOT(quit()) );
...

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is added in main.cpp or you can use QApplication::setQuitOnLastWindowClosed

Should I rewrite quit() slot?

why? take a look at QCoreApplication::quit, moreover, you can't do this since this method is not virtual. :)

no just use the connect spirit suggest you ..

quit() is a static slot
void QCoreApplication::quit () [static slot]

no need of rewrite.. its like u want to rewrite exit(0) :)

Then I guess I should try another thing, because it does not work, after widget is closed, my program keeps working.

so, provide a compilable example which reproduces the problem to us.

here main function and function which contains infinite loop

Code:

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int main(int argc, char *argv[])
{
 
	//GUI part
	QApplication a(argc, argv);
	rovkonInterface w; //subclass of Qwidget
	w.show();
 
	QObject::connect( qApp, SIGNAL(lastWindowClosed()), qApp, SLOT(quit()) );
 
	userInterface=&w;
 
	// start the receive thread
	ReceiveThread();
 
	return a.exec();
 
}
 
void ReceiveThread()
{
 
	rovkonInterface *w=((rovkonInterface *)userInterface);
	QApplication *a=((QApplication *)qtApplication);
 
 
	while ( lMustQuit == 0 )
	{	
		a->processEvents();
 
	}
 
 
}

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if you use another thread then tyr to add one more connection in main.cpp

Code:

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...
QObject::connect( qApp, SIGNAL(lastWindowClosed()), thread, SLOT(quit()) );
QObject::connect( qApp, SIGNAL(lastWindowClosed()), qApp, SLOT(quit()) );
...

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btw, you can use qApp insted of this QApplication *a=((QApplication *)qtApplication);

Thanks for the "qApp" tip.

and sorry for the bad names I gave to functions. Actually there is no other thread, there is just a function with infinite loop and I added "a->processEvents();" in order to prevent freezing in widgets as you can see in code above.

Simply ReceiveThread() continues to run infinite loop when widget is closed, I need to stop this infinite loop.

Thanks anyway :)

in rovkonInterface class
is it a QDialog or QWidget ..
if QDialog we can receive
void QDialog::rejected ()
with that rejected call we can quit our application like

Code:

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QObject::connect( w, SIGNAL(rejected()), qApp, SLOT(quit()) );

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It is Qwidget.

Code:

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rovkonInterface w; //subclass of Qwidget

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Quote:

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Originally Posted by wagmare

in rovkonInterface class
is it a QDialog or QWidget ..
if QDialog we can receive
void QDialog::rejected ()
with that rejected call we can quit our application like

Code:

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QObject::connect( w, SIGNAL(rejected()), qApp, SLOT(quit()) );

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so u try emit your custom signal on rovkonInterface closeEvent()

reimplement closeEvent() in rovkonInterface() class
emit widgetClosed() // your custom signal
and

QObject::connect( w, SIGNAL(widgetClosed()), qApp, SLOT(quit()) );

Quote:

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Originally Posted by wagmare

so u try emit your custom signal on rovkonInterface closeEvent()

reimplement closeEvent() in rovkonInterface() class
emit widgetClosed() // your custom signal
and

QObject::connect( w, SIGNAL(widgetClosed()), qApp, SLOT(quit()) );

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in that case you don't need to emit a signal, just call qApp->quit(); in closeEvent. :)