title: How to scroll up/down of bottom bar on scrolling of RecyclerView
body: <p>With Google’s recent release of the Design Support Library several cool new views have been introduced. Using some of the new components (e.g. CoordinatorLayout ) might (!) enable you to achieve the scrolling behavior.</p>
  
  <p>I was tryed with some built in scrolling behavior but nothing is working for me,</p>
  
  <p>I have a bottombar(LinearLayout) in my layout in place of FloatingActionButton</p>
  
  <p>Here what I want.</p>
  
  <ol>
  <li>OnLaunch of this screen bottom bar should appear.</li>
  <li>On scrollup of recyclerview bottom bar should scrolldown.</li>
  <li>On scrolldown of recyclerview bottom bar should scrollup</li>
  </ol>
  
  <p>Is there any builtin mechanism to achieve this ? or We need write java code?</p>
  
  <p>Here is my code:</p>
  
  <p>main_activty.xml</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"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:fitsSystemWindows="true"&gt;
  
      &lt;android.support.design.widget.AppBarLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:fitsSystemWindows="true"
          android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"&gt;
  
          &lt;include layout="@layout/toolbar_srp" /&gt;
  
          &lt;android.support.design.widget.TabLayout
              android:id="@+id/tabs"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:elevation="5dp"
              app:tabGravity="fill"
              app:tabIndicatorColor="@android:color/white"
              app:tabMode="fixed" /&gt;
  
      &lt;/android.support.design.widget.AppBarLayout&gt;
  
      &lt;!-- All Scrollable Views --&gt;
  
      &lt;android.support.v4.view.ViewPager
          android:id="@+id/viewpager"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          app:layout_behavior="@string/appbar_scrolling_view_behavior" /&gt;
  
      &lt;!-- Bottom bar--&gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_gravity="bottom"
          android:background="#a0000000"
          android:orientation="horizontal"
          android:paddingBottom="@dimen/padding_small"
          android:paddingTop="@dimen/padding_small"&gt;
  
          &lt;TextView
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.33"
              android:gravity="center"
              android:paddingBottom="@dimen/padding_small"
              android:paddingTop="@dimen/padding_small"
              android:text="AC"
              android:textColor="@color/white" /&gt;
  
          &lt;TextView
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.33"
              android:gravity="center"
              android:paddingBottom="@dimen/padding_small"
              android:paddingTop="@dimen/padding_small"
              android:text="Sleeper"
              android:textColor="@color/white" /&gt;
  
          &lt;TextView
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.33"
              android:gravity="center"
              android:paddingBottom="@dimen/padding_small"
              android:paddingTop="@dimen/padding_small"
              android:text="Premium"
              android:textColor="@color/white" /&gt;
  
      &lt;/LinearLayout&gt;
  
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>
  
  <p><strong>fragment.xml (here I was putted my recyclerview code)</strong></p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:background="@color/white"
      android:orientation="vertical"&gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="horizontal"
          android:paddingBottom="@dimen/padding_small"
          android:paddingTop="@dimen/padding_small"
          android:weightSum="1"&gt;
  
          &lt;TextView
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.33"
              android:background="@drawable/bg_srp_sorter"
              android:clickable="true"
              android:gravity="center"
              android:paddingBottom="@dimen/padding_small"
              android:paddingTop="@dimen/padding_small"
              android:text="Departure" /&gt;
  
          &lt;TextView
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.33"
              android:background="@drawable/bg_srp_sorter"
              android:gravity="center"
              android:paddingBottom="@dimen/padding_small"
              android:paddingTop="@dimen/padding_small"
              android:text="Duration" /&gt;
  
          &lt;TextView
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.33"
              android:gravity="center"
              android:paddingBottom="@dimen/padding_small"
              android:paddingTop="@dimen/padding_small"
              android:text="Price" /&gt;
  
      &lt;/LinearLayout&gt;
  
      &lt;View
          android:layout_width="match_parent"
          android:layout_height="1dp"
          android:background="@color/lite_gray"&gt;&lt;/View&gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="vertical"
          android:weightSum="1"&gt;
  
          &lt;android.support.v7.widget.RecyclerView
              android:id="@+id/bus_list_recycler_view"
              android:layout_width="match_parent"
              android:layout_height="0dp"
              android:layout_weight="1" /&gt;
  
      &lt;/LinearLayout&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p><strong>toolbar.xml</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.v7.widget.Toolbar 
  
  xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:id="@+id/toolbar"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:background="@color/colorPrimary"
      app:layout_scrollFlags="scroll|enterAlways"
      android:minHeight="?attr/actionBarSize"&gt;
  
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:weightSum="1"&gt;
  
          &lt;LinearLayout
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.10"&gt;
  
              &lt;ImageView
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:src="@drawable/abc_ic_ab_back_mtrl_am_alpha" /&gt;
  
  
          &lt;/LinearLayout&gt;
  
  
          &lt;LinearLayout
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.78"
              android:orientation="vertical"&gt;
  
              &lt;LinearLayout
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:orientation="horizontal"
                  android:weightSum="1"&gt;
  
                  &lt;TextView
                      android:id="@+id/toolbar_title_source"
                      android:layout_width="0dp"
                      android:layout_height="wrap_content"
                      android:layout_weight="0.47"
                      android:ellipsize="end"
                      android:singleLine="true"
                      android:text="Thiruvananthapuram "
                      android:textColor="@color/white"
                      android:textSize="@dimen/label_text_size_large" /&gt;
  
                  &lt;TextView
                      android:id="@+id/toolbar_title_arrow"
                      android:layout_width="0dp"
                      android:layout_height="wrap_content"
                      android:layout_weight="0.08"
                      android:text="@string/char_right"
                      android:textColor="@color/white"
                      android:textSize="@dimen/label_text_size_large"
                      android:textStyle="bold" /&gt;
  
                  &lt;TextView
                      android:id="@+id/toolbar_title_destination"
                      android:layout_width="0dp"
                      android:layout_height="wrap_content"
                      android:layout_weight="0.47"
                      android:ellipsize="end"
                      android:singleLine="true"
                      android:text=" Cochin"
                      android:textColor="@color/white"
                      android:textSize="@dimen/label_text_size_large" /&gt;
  
  
              &lt;/LinearLayout&gt;
  
  
              &lt;TextView
                  android:id="@+id/toolbar_sub_title"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:text="2 Seat(s)"
                  android:textColor="@color/lite_gray"
                  android:textSize="@dimen/label_text_size_normal" /&gt;
  
          &lt;/LinearLayout&gt;
  
  
          &lt;LinearLayout
              android:layout_width="0dp"
              android:layout_height="wrap_content"
              android:layout_weight="0.13"&gt;
  
              &lt;ImageView
                  android:layout_width="30dp"
                  android:layout_height="30dp"
                  android:scaleType="fitCenter"
                  android:src="@drawable/filter" /&gt;
          &lt;/LinearLayout&gt;
      &lt;/LinearLayout&gt;
  
  &lt;/android.support.v7.widget.Toolbar&gt;
  </code></pre>