SOLVED: Quit Application when Dialog closes

[Qatto]

Hello,

I have been trying to implement a login dialog for my new App but can't get the whole program to quit if the dialog window is closed by a user without authentication.
I am trying to overwrite the closeEvent() function for the dialog but nothing happens when its closed.
Below is the code for main.cpp, and dialog.cpp, the rest of the source & header files are the default for a new Qt MainWindow project.

main.cpp
@#include "mainwindow.h"
#include "dialog.h"
#include <QApplication>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();

//bring dialog forward at the start of the application
Dialog box;
box.setModal(true);
box.exec();

return a.exec();

}@

dialog.cpp
@#include "dialog.h"
#include "ui_dialog.h"

Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
}

Dialog::~Dialog()
{
delete ui;
}

//overwrite function for Dialog
void Dialog::closeEvent(QCloseEvent *)
{
qApp->quit();
}@

I declared the prototype void Dialog::closeEvent(QCloseEvent *) in dialog.h as public. Please advise me where am wrong, and is a dialog the best way to implement a Login feature?

Thanks in Advance

[bradenedmunds]

Qkato,

Instead of closing the application that way, it would be better to do something like this:

@switch ( dialog.exec() )
{
case QMessageBox::Cancel:
return 0;
}

return app.exec()@

Or something similar. Hope this helps.

[antseq]

Hi,

If I were you:

• I would implement 'login' inside MainWindow as an option.

• The MainWindow would be partially 'disabled' waiting for login, and fully 'enabled' (depending on user rights) after login.

• If you really want to 'quit' after a 'invalid' login you just have to 'close' the MainWindow.

• When you manage to put this (login) working manually, later (if necessary) you can find a way to trigger it automatically after the MainWindow is created.

Hope this helps.

[Qatto]

Thanks bradenedmunds,

I put the switch statement inside int main() and it worked fine except that it stops working when I delete the closeEvent() block

[Qatto]

Thanks for the reply antseq, but how exactly do I implement the login inside MainWindow?
[quote author="antseq" date="1370294153"]Hi,

If I were you:

• I would implement 'login' inside MainWindow as an option.

• The MainWindow would be partially 'disabled' waiting for login, and fully 'enabled' (depending on user rights) after login.

• If you really want to 'quit' after a 'invalid' login you just have to 'close' the MainWindow.

• When you manage to put this (login) working manually, later (if necessary) you can find a way to trigger it automatically after the MainWindow is created.

Hope this helps.[/quote]

[antseq]

[quote author="Qkato" date="1370295945"]Thanks for the reply antseq, but how exactly do I implement the login inside MainWindow?[/quote]

generally speaking:

• usually a MainWindow is 'supposed' to be the window (starting point, interface) where users interact directly with you application

• usually a MainWindow have a few (or a lot) options : Menu options, Toolbar options, Touch (screen) options or whatever you design to let the user "click" or "select" the desired command.

• you just have to add a new option/command to let the user 'login' into the system

• in response of user "clicking" or "selecting" this 'login' command, that's when you will show your 'login dialog'

• meanwhile the user has not logged in... you should keep the other MainWindow options disabled.

• It's just like when you are using a word processor and you close the document and get limited access to several menu options because you do not have a (working) document. As soon as you open a new document, you will have full access to all menu options.

[Qatto]

Thanks antseq, definitely going to look into having a login dialog from within MainWindow itself.