View state lost between onActivityResult and onResume

Question

I’m using startActivityForResult() to capture an image from the camera. While testing with the developer option “Don’t keep activities”, I noticed that my view state is being correctly restored in onViewStateRestored, but then is lost again before onActivityResult gets called. Looks like a second instance of the same fragment is being created; there are two calls to onCreate, one with a valid savedInstanceState, and another with savedInstanceState == null. The first one never gets to onResume.

This is what I see in the logs:

E/CaptureFragment﹕ fireTakePictureIntent: tempPhotoPath: /storage/emulated/0/Pictures/JPEG_2014-10-15 23.19.45.jpg
E/CaptureFragment﹕ startActivityForResult: tempPhotoPath: /storage/emulated/0/Pictures/JPEG_2014-10-15 23.19.45.jpg
I/am_on_paused_called﹕ [0,com.chimbori.galapagos.views.capture.CaptureActivity]
E/CaptureFragment﹕ onSaveInstanceState: tempPhotoPath: /storage/emulated/0/Pictures/JPEG_2014-10-15 23.19.45.jpg
E/CaptureFragment﹕ onCreate: tempPhotoPath: /storage/emulated/0/Pictures/JPEG_2014-10-15 23.19.45.jpg
E/CaptureFragment﹕ onViewStateRestored: tempPhotoPath: /storage/emulated/0/Pictures/JPEG_2014-10-15 23.19.45.jpg
E/CaptureFragment﹕ onCreate: tempPhotoPath: null
E/CaptureFragment﹕ onStart
E/CaptureFragment﹕ onActivityResult : tempPhotoPath: null
E/CaptureFragment﹕ onResume: tempPhotoPath: null
I/am_on_resume_called﹕ [0,com.chimbori.galapagos.views.capture.CaptureActivity]

The methods are straightforward:

private String tempPhotoPath;

@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  if (savedInstanceState != null && savedInstanceState.containsKey(IntentConstants.EXTRA_PHOTO_FILE)) {
    tempPhotoPath = savedInstanceState.getString(IntentConstants.EXTRA_PHOTO_FILE);
  }
  Log.e(TAG, "onCreate: tempPhotoPath: " + tempPhotoPath);
}

private void fireTakePictureIntent() {
  Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
  if (takePictureIntent.resolveActivity(getActivity().getPackageManager()) != null) {
    tempPhotoPath = FilePaths.createTempPhotoPath().getAbsolutePath();
    Log.e(TAG, "fireTakePictureIntent: tempPhotoPath: " + tempPhotoPath);
    takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(tempPhotoPath)));
    Log.e(TAG, "startActivityForResult: tempPhotoPath: " + tempPhotoPath);
    startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
  }
}

@Override
public void onSaveInstanceState(Bundle outState) {
  super.onSaveInstanceState(outState);
  if (tempPhotoPath != null) {
    Log.e(TAG, "onSaveInstanceState: tempPhotoPath: " + tempPhotoPath);
    outState.putString(IntentConstants.EXTRA_PHOTO_FILE, tempPhotoPath);
  }
}

@Override
public void onViewStateRestored(Bundle savedInstanceState) {
  super.onViewStateRestored(savedInstanceState);
  if (savedInstanceState != null && savedInstanceState.containsKey(IntentConstants.EXTRA_PHOTO_FILE)) {
    tempPhotoPath = savedInstanceState.getString(IntentConstants.EXTRA_PHOTO_FILE);
    Log.e(TAG, "onViewStateRestored: tempPhotoPath: " + tempPhotoPath);
  }
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);
  if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == Activity.RESULT_OK) {
    Log.e(TAG, "onActivityResult : tempPhotoPath: " + tempPhotoPath);
  }
}

Any ideas why it would get restored correctly on onViewStateRestored but go back to null in onActivityResult and beyond?

Answer 1

OK, I figured it out. I was re-creating the CaptureFragment in the CaptureActivity even when I was being passed a non-null savedInstanceState. That explains why two fragments were being created instead of one.

Before fix: CaptureActivity.onCreate

CaptureFragment captureFragment = new CaptureFragment();
getFragmentManager().beginTransaction()
    .replace(R.id.activity_capture_content_frame, captureFragment,
        CaptureFragment.class.getCanonicalName())
    .commit();

Fixed:

CaptureFragment captureFragment = (savedInstanceState != null)
    ? (CaptureFragment) getFragmentManager().findFragmentByTag(CaptureFragment.class.getCanonicalName())
    : new CaptureFragment();
getFragmentManager().beginTransaction()
    .replace(R.id.activity_capture_content_frame, captureFragment,
        CaptureFragment.class.getCanonicalName())
    .commit();