Force Screen Orientation on Android

Matteo Vigni

Hello,
I am currently developing an Android application. The application is, for most of the screens, meant to be used in portrait orientation, but there are a couple of screens that require the landscape orientation. What I would like to achieve is the application to modify the screen orientation base on the screen that is displayed. Kinda like what the youtube app does when you switch to full screen.
Is it there any way to achieve this behavior? If yes, which is the best way?
Thanks everybody.

raven-worx

For the whole app beginning from the startup see this.

If you want to change it dynamically during runtime i am afraid you need to do so via JNI. See this. (setRequestedOrientation on the Activity)

Matteo Vigni

Thanks raven for the reply. Yes I did already see the post about the AndroidManifest.xml but since the app will have to rotate at runtime I will have to follow the JNI way.

seyed

It's not so challenging. Use JNI as following simple implementation:

void AndroidHelper::setScreenOrientation(int orientation)
{
    QAndroidJniObject activity = QAndroidJniObject::callStaticObjectMethod("org/qtproject/qt5/android/QtNative", "activity", "()Landroid/app/Activity;");
    if ( activity.isValid() )
    {
        activity.callMethod<void>
                ("setRequestedOrientation" // method name
                 , "(I)V" // signature
                 , orientation);
    }
}

Don't forget to edit .pro file and add

android {
    QT += androidextras
    SOURCES += androidhelper.cpp #my android specific cpp file
    HEADERS += androidhelper.h   #my android specific header file
}

Matteo Vigni

Thanks seyed, your solution is working, but i had to modify it slightly as it was giving me a compile error on this line

QAndroidJniObject activity = QAndroidJniObject::callStaticObjectMethod("org/qtproject/qt5/android/QtNative", "activity", "()Landroid/app/Activity;");

So I changed it with this:

QAndroidJniObject activity = QtAndroid::androidActivity();

And it is working perfectly
Thanks everybody for the help