How to implement Qt.quit after press back button in Android QML application?

Creatorczyk

Hi,

I would like quit my application when Back button has been pressed by user. So in my QML Android application I wrote code:

main.qml

ApplicationWindow {
    id: appMainID

    visible: true
    title: qsTr("Tabs")
    signal closeWindow


    Item {
        id: myItem
        focus: true

        Keys.onReleased: {
            if(event.key === Qt.Key_Back)
            {
                event.accepted = true;
                Qt.quit
            }
        }
    }
}

main.cpp

CustomEngine engine;
    QObject::connect(&engine, &QQmlApplicationEngine::quit, &QGuiApplication::quit);
    engine.importPathList();
    const QUrl url(QStringLiteral("qrc:/main.qml"));
    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                     &app, [url](QObject *obj, const QUrl &objUrl) {
        if (!obj && url == objUrl){
            QGuiApplication::exit(-1);
        }
    }, Qt::QueuedConnection);

However, after pressing the button, the function is entered, but the application is not closed. How can I fix it so that the application closes?

JoeCFD

@Creatorczyk
try: appMainID.close()

jeremy_k

@Creatorczyk said in How to implement Qt.quit after press back button in Android QML application?:

Hi,

I would like quit my application when Back button has been pressed by user. So in my QML Android application I wrote code:

main.qml
        Keys.onReleased: {
            if(event.key === Qt.Key_Back)
            {
                event.accepted = true;
                Qt.quit
            }
        }

Qt.quit is missing the () to make it a function call.

However, after pressing the button, the function is entered

Which function?

Creatorczyk

@jeremy_k adding "()" didn't fix anything, it's still the same effect. Regarding functions, I meant the code block in "Keys.onReleased"

Creatorczyk

@JoeCFD it didn't change anything, maybe it's because something needs to be added on the Backend?

jeremy_k

@Creatorczyk said in How to implement Qt.quit after press back button in Android QML application?:

@jeremy_k adding "()" didn't fix anything

Minus a future problem anyway.

Regarding functions, I meant the code block in "Keys.onReleased"

How are you checking? Have you verified that the key code matches Key_Back? Does the same code work for a desktop application build?

An up-to-date code sample would help.

JoeCFD

@Creatorczyk What is your Android version? My call works for Android 11, 12 and 13. My app is built in Linux.

jeremy_k

@JoeCFD said in How to implement Qt.quit after press back button in Android QML application?:

@Creatorczyk
try: appMainID.close()

That looks like an attempt to trigger the QGuiApplication::quitOnLastWindowClosed behavior.