title: Android bottom navigation bar item background color change when fragment selected
body: <p>I want my bottom nav bar change background color when pressed ( only the selected area ) , 
  Like the link bellow :</p>
  
  <p><a href="http://uupload.ir/files/nq3k_tab_bar.jpg" rel="noreferrer">http://uupload.ir/files/nq3k_tab_bar.jpg</a></p>
  
  <p>Here`s my xml for the selector :</p>
  
  <pre><code>    &lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;selector xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"&gt;
      &lt;item android:state_checked="true" android:color="@color/beyez" /&gt;
      &lt;item android:state_active="true" app:itemBackground="@color/backbeyez"/&gt;
      &lt;item android:color="@color/colorPrimaryDark"  /&gt;
  &lt;/selector&gt;
  </code></pre>
  
  <p>Here`s the xml for the activity :</p>
  
  <pre><code>&lt;android.support.design.widget.BottomNavigationView
      android:id="@+id/bottomnav"
      android:layout_width="382dp"
      android:layout_height="52dp"
      android:layout_marginBottom="0dp"
      app:itemBackground="@color/colorPrimary"
      app:itemIconTint="@drawable/nav_items_color"
      app:itemTextColor="@drawable/nav_items_color"
      app:layout_constraintBottom_toBottomOf="parent"
      app:layout_constraintLeft_toLeftOf="parent"
      app:layout_constraintRight_toRightOf="parent"
  
      app:menu="@menu/navigation"
      tools:layout_editor_absoluteY="515dp"&gt;
  
  &lt;/android.support.design.widget.BottomNavigationView&gt;
  </code></pre>
  
  <p>Here`s the code for my Java Class :</p>
  
  <pre><code>@Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      switchorders();
  
      BottomNavigationView bottomNavigationView = (BottomNavigationView)findViewById(R.id.bottomnav);
      BottomNavigationViewHelper.disableShiftMode(bottomNavigationView);
  
  
      bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener()
      {
          @Override
          public boolean onNavigationItemSelected(@NonNull MenuItem item) {
  
              switch (item.getItemId())
              {
                  case R.id.navigation_orders:
                      switchorders();
                      break;
  
                  case R.id.navigation_credit:
                      switchcredits();
                      break;
  
                  case R.id.navigation_works:
                      switchworks();
                      break;
  
                  case R.id.navigation_profile:
                      switchprofile();
                      break;
  
              }
              return true;
          }
      });
  
  }
  </code></pre>
  
  <p>Thank you all for helping out !</p>