QApplication dont exit after i close all QWidget

Question

I am programming a application that return a value with QWidget::exec, but seem that i cant close the class properly (i need call Gate::~Gate explicitly for delete the class) and QApplication::exec never exit. Gate is the main window of my aplication

Gate::Gate(List *opciones, QWidget *parent):
QDialog(parent),
ui(new Ui::Gate)
{
    ParseOption *ctmp;
    int retvalue,i;
    ui->setupUi(this);
    validUser = false;
    setAttribute(Qt::WA_QuitOnClose);
    errno = 0; // no se de donde sale el error...
    [...code...]
    QObject::connect(ui->closeButton,&QAbstractButton::clicked,this,&QDialog::close);
    QObject::connect(ui->passwordField,&QLineEdit::textChanged,this,&hellGate::enableopenButton);
    QObject::connect(ui->openButton,&QAbstractButton::clicked,this,&hellGate::certificateUser);
    QObject::connect(this,&hellGate::validateUser,this,&QDialog::done);
}

when mi program call:

emit validateUser(QDialog::Accepted);

then exit, but Gate when close dont call the destructor, i call this in main but with the flag WA_QuitonClose shall close automaticaly:

int main(int argc, char *argv[])
{
    QWidgetList list;
    QApplication a(argc, argv);
    Gate w(configOptions);
    if(w.exec() == QDialog::Accepted) {
        w.~Gate();
        qDebug("enter");
    } else {
        qDebug("No enter");
    }
    list = a.topLevelWidgets();
    if(!list.isEmpty()) {
        for(int i = 0;i<list.size();i++) {
            qDebug("window: %i",list[i]->close());
        }
    } else {
        qDebug("ALL closed");
    }
    return a.exec();
}

the output is "enter" (and "ALL closed" if i call ~Gate).

i am trying that the program exit from the line "return a.exec()". if i dont destruct Gate explicitly a.topLevelWidget return a list with the a QWidget(i suppose that is Gate). i need call w.exec() because i need that Gate return a value and w.show() is declares as:

void show();

I need call w.exec and that a.exec finish when the windows w(class Gate) close. what am i doing wrong?

PD Sorry if the text is difficult to understand, i dont know English very well.

Answer 1

You create two event loops:

1. w.exec()
2. a.exec()

The second event loop is started after you close the dialog, so it will wait indefinitely for a window to be closed.

You can either call show() for the dialog or not use the QApplication event loop at all:

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Gate w(configOptions);
    if(w.exec() == QDialog::Accepted)
    {
        qDebug("enter");
    }
    else
    {
        qDebug("No enter");
    }
}