android評価星は歪みを保たない

package com.fanwe.library.customview;

import java.lang.reflect.Field;

import android.content.Context;
import android.graphics.Bitmap;
import android.util.AttributeSet;
import android.widget.RatingBar;

public class SDRatingBar extends RatingBar
{

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

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

    public SDRatingBar(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
    }

    @Override
    protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        try
        {
            Class> clazz = Class.forName("android.widget.ProgressBar");
            Field field = clazz.getDeclaredField("mSampleTile");
            field.setAccessible(true);
            Object bitmapObject = field.get(this);
            Bitmap bitmap = (Bitmap) bitmapObject;
            int height = bitmap.getHeight();
            if (height > 0)
            {
                setMeasuredDimension(getMeasuredWidth(), resolveSizeAndState(height, heightMeasureSpec, 0));
            }
        } catch (Exception e)
        {
            e.printStackTrace();
        }
    }
}