parallaxpager/src/main/java/com/prolificinteractive/parallaxpager/ParallaxContainer.java
private void addParallaxView(View view, int pageIndex) {
    if (view instanceof ViewGroup) {
      // recurse children
      ViewGroup viewGroup = (ViewGroup) view;
      for (int i = 0, childCount = viewGroup.getChildCount(); i < childCount; i++) {
        addParallaxView(viewGroup.getChildAt(i), pageIndex);
      }
    }

    ParallaxViewTag tag = (ParallaxViewTag) view.getTag(R.id.parallax_view_tag);
    if (tag != null) {
      // only track view if it has a parallax tag
      tag.index = pageIndex;
      parallaxViews.add(view);
    }
  }
private void addParallaxView(View view, int pageIndex) {
    if (view instanceof ViewGroup) {
      // recurse children
      ViewGroup viewGroup = (ViewGroup) view;
      for (int i = 0, childCount = viewGroup.getChildCount(); i < childCount; i++) {
        addParallaxView(viewGroup.getChildAt(i), pageIndex);
      }
    }

    ParallaxViewTag tag = (ParallaxViewTag) view.getTag(R.id.parallax_view_tag);
    if (tag != null) {
      // only track view if it has a parallax tag
      tag.index = pageIndex;
      parallaxViews.add(view);
    }
  }
attach attributes in tag