[SOLVED] QWidget setVisible not executed?

[maximus]

I have a QPushButton that is connected to a function "login" :
@connect(ui->loginButton, SIGNAL(clicked()), this, SLOT(login()) );@

At the start of the login function, I set a QWidget visible (to show that application is loading) and right before going out of the login function, I hide this widget. My problem is that the widget never get visible. Is there something that i'm not seeing, it's just a procedural function, I dont' think I need thread for that?

Here is my login function :
@void DialogLogin::login() {

setLoadingInterface(true);

QString username = ui->lineEdit_username->text();
QString pw = ui->lineEdit_pw->text();

bool loginAccepted = loginHelper(username, pw);

if (loginAccepted) {
    QDialog::accept();
}
else {
    QDialog::rejected();
}
setLoadingInterface(false);

}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void DialogLogin::setLoadingInterface(bool enabled) {

qDebug() << "change button state: " << enabled;
ui->loginButton->setEnabled(!enabled);
labelLoading->setVisible(enabled);
ui->loginButton->repaint();
labelLoading->repaint();
if (enabled)
    disconnect(ui->loginButton, SIGNAL(clicked()), this, SLOT(login()) );
else
    connect(ui->loginButton, SIGNAL(clicked()), this, SLOT(login()) );

}
@

Log:
change button state: true
LOG: "SELECT id, username, first_name, last_name, birthdate, sex, email, weight, height, FTP, LTHR, KM_done FROM user WHERE BINARY username='fdsafs'"
Bad password or username
change button state: false

[maximus]

found some answers here:
http://qt-project.org/forums/viewthread/4780

But it still not working as expected, even when the button is gray, I can click on it, resulting in 2 query to the database... I updated the code up here

[maximus]

Apparently the GUI Thread is stuck and nothing can by-pass that.

I saw some people suggesting running an external QProcess that show a loading animation and block the application, what?! there must a better way to do that? I mean blocking a button waiting for an action to finish is a common task...

[Edit: It seems I can put my SqlQuery in a thread in order to liberate the UI.. working on it:
http://www.linuxjournal.com/article/9602?page=0,2]