override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        setSupportActionBar(toolbar)
        bottomNavigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener)

        if (savedInstanceState == null) {
            initFragments()
        } else {
            atHome = savedInstanceState.getBoolean("atHome")
        }
    }




private val mOnNavigationItemSelectedListener =
            BottomNavigationView.OnNavigationItemSelectedListener { item ->
                when (item.itemId) {
                    R.id.navigation_home -> {
                        supportFragmentManager.beginTransaction()
                                .hide(active).show(mFragment0).commit()
                        active = mFragment0
                        atHome = true
                        return@OnNavigationItemSelectedListener true
                    }
                    R.id.navigation_profile -> {
                        supportFragmentManager.beginTransaction()
                                .hide(active).show(mFragment1).commit()
                        active = mFragment1
                        atHome = false
                        return@OnNavigationItemSelectedListener true
                    }
                    R.id.navigation_relation -> {
                        supportFragmentManager.beginTransaction()
                                .hide(active).show(mFragment2).commit()
                        active = mFragment2
                        atHome = false
                        return@OnNavigationItemSelectedListener true
                    }
                    R.id.navigation_members -> {
                        supportFragmentManager.beginTransaction()
                                .hide(active).show(mFragment3).commit()
                        active = mFragment3
                        atHome = false
                        return@OnNavigationItemSelectedListener true
                    }
                    R.id.navigation_requests -> {
                        supportFragmentManager.beginTransaction()
                                .hide(active).show(mFragment4).commit()
                        active = mFragment4
                        atHome = false
                        return@OnNavigationItemSelectedListener true
                    }
                }
                false
            }

    override fun onCreateOptionsMenu(menu: Menu): Boolean {
        menuInflater.inflate(R.menu.main_menu, menu)
        return true
    }



/** This function will add all fragments to the fragment manager cache
  * and show home fragment as current page
  */
private fun initFragments() {

        //Fragment Transaction for Initial Startup
        supportFragmentManager.beginTransaction()
                .add(R.id.contentFrame, mFragment0, R.string.fragment_title_home).commit()
        supportFragmentManager.beginTransaction()
                .add(R.id.contentFrame, mFragment1, R.string.fragment_title_profile).hide(mFragment1).commit()
        supportFragmentManager.beginTransaction()
                .add(R.id.contentFrame, mFragment2, R.string.fragment_title_relation).hide(mFragment2).commit()
        supportFragmentManager.beginTransaction()
                .add(R.id.contentFrame, mFragment3, R.string.fragment_title_members).hide(mFragment3).commit()
        supportFragmentManager.beginTransaction()
                .add(R.id.contentFrame,mFragment4, R.string.fragment_title_requests).hide(mFragment4).commit()
        atHome = true
    }