@Override
 public void onItemClick(AdapterView<?> l, View v, int position, long id) {
   if (l.getId() == R.id.photosGridView) {
     String clickedItem = photosGridViewContents[position];
     Intent intent = new Intent(PhotoGridActivity.this, PhotoViewerActivity.class);
     intent.putExtra(
         "filename",
         clickedItem); // use putExtra method of Intent here for passing additional information to
                       // PhotoViewerActivity
     startActivity(intent);
   }
 }