Callback after orientation change becomes null

Question

I have have a FragmentActivity with two tabs which are ListFragments. Each ListFragment has a callback.

An example of a callback

The callback is associated inside of the onAttach(...) method

OnStatusUpdateListener mStatusUpdateCallback;

public interface OnStatusUpdateListener {
    public void onStatusUpdate();
}

@Override
public void onAttach(Activity activity) {
    Log.d(TAG, "onAttach");
    super.onAttach(activity);

    try {
        mStatusUpdateCallback = (OnStatusUpdateListener)activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString() + " must implement OnStatusUpdateListener");
    }
}

@Override
public void onCreate(Bundle savedInstanceState) {
    Log.d(TAG, "onCreate");
    super.onCreate(savedInstanceState);

    setRetainInstance(true);
}

Later on, I communicate with the FragmentActivity by this callback which works fine normally.

Within the ListFragment, I have an ImageButton that will call a DialogFragment which also has a callback. This callback is implemented in my ListFragment and is what triggers the callback that is null

public void onStatusOption() {
    Log.d(TAG, "onStatusOption");

    // Update stuff

    // Here is where mStatusUpdateCallback is null after rotate
    mStatusUpdateCallback.onStatusUpdate();
}

The problem is that if I ever rotate the phone while the application is running, mStatusUpdateCallback becomes null. This of course means I cannot execute the callback. Does anyone know how to fix this?

What I've tried

According to https://stackoverflow.com/a/6029070/935779 it appears that a new reference to OnStatusUpdateListener may have been created so I cannot reference the old, but doesn't offer a solution.

I've also tried retaining the state as per https://stackoverflow.com/a/6787393/935779, but I can't save a reference to a callback as far as I can tell.

I also would really rather not do the android:configChanges="orientation|keyboardHidden" method since that just seems like a hack and my layout changes in landscape.

Stacktrace

FATAL EXCEPTION: main
java.lang.NullPointerException
    at com.blug.blah.Fragment.StatusFragment.onStatusOption(StatusFragment.java:197)
    at com.blug.blah.MyActivity.onStatusOption(MyActivity.java:243)
    at com.blug.blah.Dialog.StatusOptionDialog$1$1.onClick(StatusOptionDialog.java:108)
    at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:158)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:123)
    at android.app.ActivityThread.main(ActivityThread.java:4627)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:521)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
    at dalvik.system.NativeStart.main(Native Method)

Answer 1

When configuration of the Activity being destroy and recreates.

When Configuration of the phone is changed the method onConfigurationChange called.

So you can initialize your Callbacks in onConfigurationChange

Answer 2

First you can put this code into manifest tag and force activity to save your callback android:configChanges="orientation|screenSize" and Second you can use onConfigurationChange method to initialize your callback