[SOLVED] [Android] [Qt 5.2] How to get activity object?

rom8726

I need to get main activity, and I tried:
[code]
QAndroidJniEnvironment jniEnv;
jclass clsAct = jniEnv->FindClass("android/app/Activity");
qDebug() << "Activity: " << clsAct;

if( QAndroidJniObject::isClassAvailable("org/qtproject/qt5/android/bindings/QtActivity") )
{
jclass clsApp = jniEnv->FindClass("org/qtproject/qt5/android/bindings/QtActivity");
qDebug() << "QtActivity: " << clsApp;

if( clsApp && clsAct )
{
    jobject objAct = NULL;
    jmethodID mid = jniEnv->GetStaticMethodID( clsApp, "activity", "()Landroid/app/Activity;" );
    qDebug() << "activityMID: " << mid;

    if( mid )
    {
        objAct = jniEnv->CallStaticObjectMethod( clsApp, mid );
        qDebug() << "activityObj: " << objAct;
    }
}

}
[/code]
But on jniEnv->FindClass("org/qtproject/qt5/android/bindings/QtActivity") shoots error:
[code]
D/Qt ( 4074): mainwindow.cpp:32 (MainWindow::MainWindow(QWidget*)): >>>>>> QtActivity: 0x0
W/dalvikvm( 4074): JNI WARNING: JNI function CallStaticVoidMethodV called with exception pending
W/dalvikvm( 4074): in Ldalvik/system/NativeStart;.run:()V (CallStaticVoidMethodV)
W/dalvikvm( 4074): Pending exception is:
I/dalvikvm( 4074): java.lang.NoClassDefFoundError: org/qtproject/qt5/android/bindings/QtActivity
I/dalvikvm( 4074): at dalvik.system.NativeStart.run(Native Method)
I/dalvikvm( 4074): Caused by:
I/dalvikvm( 4074): java.lang.ClassNotFoundException: Didn't find class "org.qtproject.qt5.android.bindings.QtActivity" on path: DexPathList[[directory "."],nativeLibraryDirectories=[/system/lib]]
[/code]

ahmad88me

I couldn't use this approach, but what ever you want you can try to edit the generated java code

benlau

Try this piece of code:

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

T.Iotti

I've looked to a lot of posts explaining how to sort this problem, but the only one thing that worked was this:

I was in QT 5.2:

first:

in your .pro:
@QT += gui-private@

now in your cpp:
@

#include <QAndroidJniObject>
#include <qpa/qplatformnativeinterface.h>

QAndroidJniObject getMainActivity()
{
QPlatformNativeInterface *interface = QApplication::platformNativeInterface();
QAndroidJniObject activity = (jobject)interface->nativeResourceForIntegration("QtActivity");

if(!activity.isValid())
qDebug()<<"CLASS NOT VALID!!!!!!!!";
else
qDebug()<<"HORRAY!";

return activity;
}
@

I also like to thanks the MontezooM post which helped me to figure out

_______________-________________

@T-Iotti

hi I know its quite old but maybe this will help someone like me stumbing across this : just call this funcion through jni

static Activity getActivity() {
           try {
               Class activityThreadClass = Class.forName("android.app.ActivityThread");
               Object activityThread = activityThreadClass.getMethod("currentActivityThread").invoke(null);
               Field activitiesField = activityThreadClass.getDeclaredField("mActivities");
               activitiesField.setAccessible(true);

               Map<Object, Object> activities = (Map<Object, Object>) activitiesField.get(activityThread);
               if (activities == null)
                   return null;

               for (Object activityRecord : activities.values()) {
                   Class activityRecordClass = activityRecord.getClass();
                   Field pausedField = activityRecordClass.getDeclaredField("paused");
                   pausedField.setAccessible(true);
                   if (!pausedField.getBoolean(activityRecord)) {
                       Field activityField = activityRecordClass.getDeclaredField("activity");
                       activityField.setAccessible(true);
                       return (Activity) activityField.get(activityRecord);
                   }
               }

               return null;
           }
           catch (Exception e)
           {
               return null;
           }
       }