title: Showing a hidden toolbar animation not smooth
body: <p>in one of my recent apps I implemented the hide/show toolbar when the user is scrolling in a list (Recyclerview). My app has 3 fragments and a view pager to present them.The toolbar hides appropriately when scrolling. However, when I change the fragment (onPageChange listener is called on the view page) I am expanding the toolbar. Sometimes when it is expanding the animation is smooth, but sometimes there is a slight delay. I dont understand what I am doing wrong.
  To illustrate this I recorded my screen, please lick <a href="https://youtu.be/0ZlB-hHJHjA" rel="nofollow">here</a> to see the video.</p>
  
  <p>This is my main_layout:</p>
  
  <pre><code>&lt;android.support.design.widget.CoordinatorLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:fab="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:fitsSystemWindows="true"
  tools:context="com.studentsins.lust.MainActivity"&gt;
  
  &lt;android.support.design.widget.AppBarLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:id="@+id/appBarLayouy"
      android:theme="@style/AppTheme.AppBarOverlay"&gt;
  
      &lt;android.support.v7.widget.Toolbar
          android:id="@+id/toolbar"
          android:layout_width="match_parent"
          android:layout_height="?attr/actionBarSize"
          android:background="?attr/colorPrimary"
          app:popupTheme="@style/AppTheme.PopupOverlay"
          app:layout_scrollFlags="scroll|enterAlways" /&gt;
  
      &lt;android.support.design.widget.TabLayout
          android:id="@+id/sliding_tabs"
          android:layout_width="match_parent"
          android:layout_height="@dimen/tabsHeight"
          style="@style/NavigationTab"/&gt;
  
  
  &lt;/android.support.design.widget.AppBarLayout&gt;
  
  &lt;android.support.v4.view.ViewPager
      android:id="@+id/viewpager"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      app:layout_behavior="@string/appbar_scrolling_view_behavior"/&gt;
  
  
  &lt;include layout="@layout/content_main"/&gt;
  
  &lt;com.getbase.floatingactionbutton.FloatingActionsMenu
      android:id="@+id/floatingActionMenu"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentRight="true"
      android:layout_alignParentEnd="true"
      fab:fab_addButtonColorNormal="@color/blood_orange"
      fab:fab_addButtonColorPressed="@color/dirtyWhite"
      fab:fab_addButtonPlusIconColor="@color/dirtyWhite"
      fab:fab_addButtonSize = "normal"
      fab:fab_labelStyle="@style/menu_labels_style"
      fab:fab_labelsPosition="left"
      app:layout_anchor="@id/viewpager"
      app:layout_anchorGravity="bottom|end"&gt;
  
      &lt;com.getbase.floatingactionbutton.FloatingActionButton
          android:id="@+id/createPlanBtn"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          fab:fab_colorNormal="@color/blood_orange"
          fab:fab_title="Create a plan"
          fab:fab_size="normal"
          app:fab_icon="@drawable/ic_event_white_48dp"
          fab:fab_colorPressed="@color/dirtyWhite"/&gt;
  
      &lt;com.getbase.floatingactionbutton.FloatingActionButton
          android:id="@+id/changeStatusBtn"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          fab:fab_colorNormal="@color/blood_orange"
          fab:fab_size="normal"
          app:fab_icon="@drawable/ic_textsms_white_48dp"
          fab:fab_title="Change status"
          fab:fab_colorPressed="@color/dirtyWhite"/&gt;
  
  &lt;/com.getbase.floatingactionbutton.FloatingActionsMenu&gt;
  </code></pre>
  
  <p></p>
  
  <p>This is my feed_fragment:</p>
  
  <pre><code>public class FeedFragment extends Fragment {
  public static final String ARG_PAGE = "ARG_PAGE";
  private static final String TAG = FeedFragment.class.getSimpleName();
  private int mPage;
  private RecyclerView mRefreshLayout;
  private Context mActivity;
  
  public static FeedFragment newInstance(int page) {
      Bundle args = new Bundle();
      args.putInt(ARG_PAGE, page);
      FeedFragment fragment = new FeedFragment();
      fragment.setArguments(args);
      return fragment;
  }
  
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      mPage = getArguments().getInt(ARG_PAGE);
      mActivity = getActivity();
      Log.d("MainActivity", "onCreate" + mPage);
  }
  
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      View view = inflater.inflate(R.layout.fragment_feed_layout,container,false);
  
      mRefreshLayout = (RecyclerView) view.findViewById(R.id.feedCardViewList);
      LinearLayoutManager linearLayoutManager = new LinearLayoutManager(mActivity);
      linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
      mRefreshLayout.setLayoutManager(linearLayoutManager);
  
      mRefreshLayout.addOnScrollListener(new RecyclerView.OnScrollListener() {
          @Override
          public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
              super.onScrolled(recyclerView, dx, dy);
  
              if (dy &gt;= 0) {
                  // Scrolling up.. hide the FAB
                  MainActivity.mFloatingActionsMenu.animate()
                          .setDuration(150)
                          .translationY(300);
              } else {
                  // Scrolling down.. show the FAB
                  MainActivity.mFloatingActionsMenu.animate()
                          .setDuration(150)
                          .translationY(0);
              }
  
              Log.d(TAG,"DY value: "+dy);
  
          }
      });
      ArrayList&lt;String&gt; users = new ArrayList&lt;&gt;();
      users.add("Georgi Koemdzhiev");
      users.add("Mariya Menova");
      users.add("Simeon Simeonov");
      users.add("Ivan Dqkov");
      users.add("Dymityr Vasilev");
      users.add("Petar Dimov");
      users.add("Stoyan Stoyanov");
      users.add("Alexander Lunar");
      users.add("Awesome Jhon");
  
      FeedCardAdapter adapter = new FeedCardAdapter(users,mActivity);
  
      mRefreshLayout.setAdapter(adapter);
      Log.d("MainActivity", "onCreateView" + mPage);
      return view;
  }
  }
  </code></pre>
  
  <p>This is my MainActivity onCreate method:</p>
  
  <pre><code>protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
      setSupportActionBar(toolbar);
  
  
      sharedPreferences = PreferenceManager.getDefaultSharedPreferences(MainActivity.this);
      editor = sharedPreferences.edit();
  
     Boolean isUserLoggedIn = sharedPreferences.getBoolean(Constants.USER_IF_LOG_IN,false);
      if(!isUserLoggedIn){
          navigateToLogin();
      }
  
      // Get the ViewPager and set it's PagerAdapter so that it can display items
      final ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
      viewPager.setAdapter(new LustFragmentPagerAdapter(getSupportFragmentManager(), this));
      // Give the TabLayout the ViewPager
      final TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
      tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
      tabLayout.setupWithViewPager(viewPager);
  
      mFloatingActionsMenu = (FloatingActionsMenu)findViewById(R.id.floatingActionMenu);
  
      mChangeStatus = (FloatingActionButton)findViewById(R.id.changeStatusBtn);
      mChangeStatus.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View view) {
              Log.d(TAG,"Change Status pressed! | " + viewPager.getCurrentItem());
              mFloatingActionsMenu.collapse();
          }
      });
      mCreatePlan = (FloatingActionButton)findViewById(R.id.createPlanBtn);
      mCreatePlan.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View view) {
              Log.d(TAG,"Create plan pressed! | " + viewPager.getCurrentItem());
              mFloatingActionsMenu.collapse();
          }
      });
  
      viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
          @Override
          public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
              //Make sure that the fab is visible when scrolling the pages...
              MainActivity.mFloatingActionsMenu.animate()
                      .setDuration(150)
                      .translationY(0);
              //show the toolbar
              expandToolbar();
  
          }
  
          @Override
          public void onPageSelected(int position) {
  
          }
  
          @Override
          public void onPageScrollStateChanged(int state) {
  
          }
      });
  
  
  }
  </code></pre>
  
  <p>this is my expandToolbar method code:</p>
  
  <pre><code>public void expandToolbar(){
      //setExpanded(boolean expanded, boolean animate)
      AppBarLayout appBarLayout = (AppBarLayout)findViewById(R.id.appBarLayouy);
      appBarLayout.setExpanded(true, true);
  }
  </code></pre>