Make it possible to use custom centered background resource in MaterialDrawer library

DrawerItemWithBadgeInCircle.java

package com.viorsan.gists.example1

import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.mikepenz.materialdrawer.model.PrimaryDrawerItem;


/**
 * Created by Dmitriy Kazimirov, e-mail dmitriy.kazimirov@viorsan.com on 10.06.15.
 * PrimaryDrawerItem which correctly can display badge in circle which is correctly centered
 * directly access PrimaryDrawerItem's inner elements
 *
 */
public class DrawerItemWithBadgeInCircle extends PrimaryDrawerItem {

    private int badgeBackgroundRes = -1;


    public DrawerItemWithBadgeInCircle withBadgeBackgroundRes(int backgroundRes) {
        this.badgeBackgroundRes = backgroundRes;
        return this;
    }

    /***
     * Update badge to use circle background using our knowledge of PrimaryDriverItem's  inner structure
     * @param inflater
     * @param convertView
     * @param parent
     * @return
     */
    @Override
    public View convertView(LayoutInflater inflater, View convertView, ViewGroup parent) {
        //use the logic of regular PrimaryDrawerItem
        convertView = super.convertView(inflater, convertView, parent);

        if (badgeBackgroundRes!=-1) {
            //add configure background resource
            TextView badge=(TextView)convertView.findViewById(R.id.badge);
            badge.setBackgroundResource(badgeBackgroundRes);
            //put it into correct place
            RelativeLayout.LayoutParams lp=(RelativeLayout.LayoutParams)badge.getLayoutParams();
            lp.width=convertView.getResources().getDimensionPixelSize(R.dimen.navigation_drawer_badge_width);
            lp.height=convertView.getResources().getDimensionPixelSize(R.dimen.navigation_drawer_badge_height);
            lp.addRule(RelativeLayout.CENTER_VERTICAL);
            badge.setLayoutParams(lp);
            //fix position
            badge.setGravity(Gravity.CENTER);
        }
        return convertView;
    }
}