enabling/disabling a QMainWindow?

[fullmetalcoder]

The signal i emit leads to a slot that does some things before issuing a qApp->quit().

Have you tried commenting out this signal emission? BTW If you issue a "qApp->quit()" your app should actually get closed and not disabled or am I missing something?

[TheRonin]

hey guys, thanks for your help thus far...i hope there's a solution right around the corner!

I don't think this is the case but you may just try with another widget style and see for yourself.

I get the desired behavior if instead of disabling the QMainWindow i disable the root widget (a QWidget called centralwidget by the designer). I would of course like to not need to do that sort of work-around instead of working with the mainwindow directly. Had you been able to reproduce my problem i would have been tempted to call it a bug of sorts but since i seem to be the only one affected, maybe it's due to a problem with my Qt installation??

Have you tried commenting out this signal emission? BTW If you issue a "qApp->quit()" your app should actually get closed and not disabled or am I missing something?

I just tried skipping the signal emission like you suggested but the mainwindow still doesn't get disabled (unless i disable the centralwidget). You're absolutely right about the quit() terminating the application but there is a significant amount of time between the emission of the signal and the actual call to quit() (i do a bunch of stuff in-between that takes time...like closing tcp connections and saving things to file.)

[wysota]

Could you prepare a minimal compilable example reproducing the problem?

[TheRonin]

Could you prepare a minimal compilable example reproducing the problem?

Sorry for the delayed response...here comes the 'minimal' example. When run on my system the main window does not become disabled unless i use the centralwidget-object

#include <iostream>
#include <QApplication>
#include <QMainWindow>
#include <QWidget>
#include <QPushButton>
#include <QString>
//#include <QRect>
//#include <QSize>
//
using namespace std;
//
class Gui : public QMainWindow
{
	Q_OBJECT
public:
	Gui( QWidget * parent = 0 );	
private slots:
	void disableMe();
private:
	QWidget *centralwidget;
	QPushButton *pushButton;
};
 
int main(int argc, char ** argv)
{
	QApplication app( argc, argv );
	Gui gui;
	gui.show(); 		     
	app.connect( &app, SIGNAL( lastWindowClosed() ), &app, SLOT( quit() ) );
	return app.exec();
}
 
Gui::Gui( QWidget * parent ) : QMainWindow(parent)
{	
	this->setObjectName(QString::fromUtf8("MainWindow"));
	this->setWindowTitle("main window test");
	centralwidget = new QWidget(this);
	centralwidget->setObjectName(QString::fromUtf8("centralwidget"));
	pushButton = new QPushButton(centralwidget);
	pushButton->setObjectName(QString::fromUtf8("pushButton"));
	pushButton->setGeometry(QRect(110, 50, 101, 41));
   	pushButton->setText("disable?");
	this->setCentralWidget(centralwidget);
 
	QSize size(322, 149);
	size = size.expandedTo(this->minimumSizeHint());
	this->resize(size);
 
	connect(pushButton, SIGNAL(clicked()),
			this, SLOT(disableMe()));
}
 
void Gui::disableMe()
{
	cout << "trying to disable the mainwindow...";
	this->setDisabled(true);
	cout << "success?" << endl;
}

#include <iostream>
#include <QApplication>
#include <QMainWindow>
#include <QWidget>
#include <QPushButton>
#include <QString>
//#include <QRect>
//#include <QSize>
//
using namespace std;
//
class Gui : public QMainWindow
{
	Q_OBJECT
public:
	Gui( QWidget * parent = 0 );	
private slots:
	void disableMe();
private:
	QWidget *centralwidget;
	QPushButton *pushButton;
};

int main(int argc, char ** argv)
{
	QApplication app( argc, argv );
	Gui gui;
	gui.show(); 		     
	app.connect( &app, SIGNAL( lastWindowClosed() ), &app, SLOT( quit() ) );
	return app.exec();
}

Gui::Gui( QWidget * parent ) : QMainWindow(parent)
{	
	this->setObjectName(QString::fromUtf8("MainWindow"));
	this->setWindowTitle("main window test");
	centralwidget = new QWidget(this);
	centralwidget->setObjectName(QString::fromUtf8("centralwidget"));
	pushButton = new QPushButton(centralwidget);
	pushButton->setObjectName(QString::fromUtf8("pushButton"));
	pushButton->setGeometry(QRect(110, 50, 101, 41));
   	pushButton->setText("disable?");
	this->setCentralWidget(centralwidget);

	QSize size(322, 149);
	size = size.expandedTo(this->minimumSizeHint());
	this->resize(size);
	
	connect(pushButton, SIGNAL(clicked()),
			this, SLOT(disableMe()));
}

void Gui::disableMe()
{
	cout << "trying to disable the mainwindow...";
	this->setDisabled(true);
	cout << "success?" << endl;
}

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[wysota]

Seems to work fine for me (Linux+4.2.3+Plastique). Works well on CDE and Cleanlooks as well.

[jpn]

And works for me on Qt4.2.3/Win with both, winxp and windows styles too.

[TheRonin]

Seems to work fine for me (Linux+4.2.3+Plastique). Works well on CDE and Cleanlooks as well.

And works for me on Qt4.2.3/Win with both, winxp and windows styles too.

You're kidding!? Haha, that is too weird. Things are pointing more and more towards there being a problem with my installation. I just can't see any other reason for the behavior.

[wysota]

Did the code I pasted at the beginning of the thread work for you?

[TheRonin]

Did the code I pasted at the beginning of the thread work for you?

no luck there either unfortunately

[wysota]

Oh, you could have said so earlier.. From what you said I understood it had worked.

[TheRonin]

Oh, you could have said so earlier.. From what you said I understood it had worked.

I'm sorry, i should have been more clear. What i meant was that the example works if i disable the centralwidget instead of trying to disable the mainwindow. This is a little easier in my example since i there have direct access to the centralwidget. In either case, i shouldn't have to though, hence the annoyance.

[wysota]

What is your exact work environment? Platform, Qt version (compiled/binary), toolchain...?