Quit the application when QWidget is closed

Knj.Tkm

Hi.
I want to quit the application when QWidget is closed.
But there is no signal when QWidget close.

Is there any way to know that QWidget is closed?

jsulm

@Knj-Tkm said in Quit the application when QWidget is closed:

How do I use it?

You need to override closeEvent in your class.

class MainWin: public QMainWindow
{
private:
    void closeEvent(QCloseEvent *event) override;
}

void MainWin::closeEvent(QCloseEvent *event)
{
    qDebug() << "Closing";
    event->accept();
}

Is MainWin a QMainWindow? I'm wondering why you need to close your app manually when main window is closed, this should happen automatically.

jeremy_k

~~QWidget::showEvent() can be overridden to detect when a widget is hidden.~~

QGuiApplication::setQuitOnLastWindowClosed() is likely what you're looking for.

jsulm

@Knj-Tkm said in Quit the application when QWidget is closed:

But there is no signal when QWidget close.

But there is https://doc.qt.io/qt-5/qwidget.html#closeEvent

Knj.Tkm

@jeremy_k
How to use?
I try to this code, but no work.

void MainWin::showEv(QShowEvent *ev)
{
    QWidget::showEvent(ev);
    qDebug() << "Close";
}

Knj.Tkm

@jsulm
QCloseEvent don't work.
How do I use it?

void MainWin::closeEv(QCloseEvent *event)
{
    qDebug() << "HERE";
    event->accept();
}

jsulm

@Knj-Tkm said in Quit the application when QWidget is closed:

How do I use it?

You need to override closeEvent in your class.

class MainWin: public QMainWindow
{
private:
    void closeEvent(QCloseEvent *event) override;
}

void MainWin::closeEvent(QCloseEvent *event)
{
    qDebug() << "Closing";
    event->accept();
}

Is MainWin a QMainWindow? I'm wondering why you need to close your app manually when main window is closed, this should happen automatically.

Knj.Tkm

@jsulm
It get error
[ error: only virtual member functions can be marked 'override']
Sorry, It work.
I got the code a little wrong.

I use QWidget.
I'm creating an application window with QWidget.
I just want the application to quit when I close QWidget.

jsulm

@Knj-Tkm The you should rather do what @jeremy_k suggested: set QGuiApplication::setQuitOnLastWindowClosed()