ViewPager that draws the children in the correct order

CorrectChildDrawingViewPager.java

package android.support.v4.view;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

/**
 * Viewpager that will draw childview in the order of the adapter.
 */
public class CorrectChildDrawingViewPager extends ViewPager
{
	private ArrayList<View> mDrawingOrderedChildren;
	private final PositionComparator sPositionComparator = new PositionComparator();

	public CorrectChildDrawingViewPager(Context context)
	{
		super(context);
	}

	public CorrectChildDrawingViewPager(Context context, AttributeSet attrs)
	{
		super(context, attrs);
	}

	@Override
	protected int getChildDrawingOrder(int childCount, int i)
	{
		final int result = ((LayoutParams) mDrawingOrderedChildren.get(i).getLayoutParams()).childIndex;
		return result;
	}

	@Override
	void populate(int newCurrentItem)
	{
		super.populate(newCurrentItem);
		//sort the children.
		this.sortChildDrawing();
	}

	/**
	 * Sort our children, this is copied from inside ViewPager.
	 */
	private void sortChildDrawing()
	{
		if (mDrawingOrderedChildren == null)
		{
			mDrawingOrderedChildren = new ArrayList<>();
		}
		else
		{
			mDrawingOrderedChildren.clear();
		}
		final int childCount = getChildCount();
		for (int i = 0; i < childCount; i++)
		{
			final View child = getChildAt(i);
			mDrawingOrderedChildren.add(child);
		}
		Collections.sort(mDrawingOrderedChildren, sPositionComparator);
	}

	class PositionComparator implements Comparator<View>
	{
		@Override
		public int compare(View lhs, View rhs)
		{
			final LayoutParams llp = (LayoutParams) lhs.getLayoutParams();
			final LayoutParams rlp = (LayoutParams) rhs.getLayoutParams();
			if (llp.isDecor != rlp.isDecor)
			{
				return llp.isDecor ? 1 : -1;
			}
			//LayoutParams.position is only set in certain locations.
			//Use ItemInfo.position which has the correct position
			final ItemInfo lii = infoForChild(lhs);
			final ItemInfo rii = infoForChild(rhs);
			return lii.position - rii.position;
		}
	}
}