title: Android Collapsing Toolbar not using inertia like Google Play App does
body: <p>I'm using the Android Design Support Library to create an Activity with a Collapsible Toolbar with a nice fading effect, just like Google Play or Whatsapp's Contact profile. I will put the activity layout at the end but bear in mind this is just the default Collapsible Activity layout to which I added an ImageView to the AppBarLayout to create the Toolbar &lt;-> Image fade effect.</p>
  
  <p>My problem with this implementation presents itself as 2 symptoms I will describe:</p>
  
  <ul>
  <li><p>The activity content is long, when I want to scroll up quickly with a fast swipe the scroll will stop before expanding the Toolbar. I want it to continue, when I'm at the bottom of my NestedScrollView and I do a quick finger swipe to go all the way to the top of my activity I want this scroll to go and expand the Toolbar, this is the way the Google Play app behaves or Whatsapp's profile does.</p></li>
  <li><p>Similarly when the Toolbar is expanded there is no inertia to the scroll, a quick swipe down will scroll a tiny bit, again this is not how Google Play or Whatsapp profile behaves. Once the Toolbar is collapsed the scroll behaves as it always has in ScrollViews, ListViews, etc. A quick swipe will allow you to go the bottom or top (unless there is a lot of content).</p></li>
  </ul>
  
  <p>Is the behaviour I describe supported by the Design Support Library?</p>
  
  <p>activity.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &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:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:fitsSystemWindows="true"
      tools:context=".ScrollingActivity"&gt;
  
      &lt;android.support.design.widget.AppBarLayout
          android:id="@+id/app_bar"
          android:fitsSystemWindows="true"
          android:layout_height="@dimen/app_bar_height_custom"
          android:layout_width="match_parent"
          android:theme="@style/AppTheme.AppBarOverlay"&gt;
  
          &lt;android.support.design.widget.CollapsingToolbarLayout
              android:id="@+id/toolbar_layout"
              android:fitsSystemWindows="true"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              app:layout_scrollFlags="scroll|exitUntilCollapsed"
              app:contentScrim="?attr/colorPrimary"&gt;
  
              &lt;ImageView
                  android:src="@drawable/cuthbert"
                  app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:scaleType="centerCrop"
                  app:layout_collapseMode="parallax"
                  android:minHeight="100dp"/&gt;
  
              &lt;android.support.v7.widget.Toolbar
                  android:id="@+id/toolbar"
                  android:layout_height="?attr/actionBarSize"
                  android:layout_width="match_parent"
                  app:layout_collapseMode="parallax"
                  app:layout_scrollFlags="scroll|enterAlways"
                  app:popupTheme="@style/AppTheme.PopupOverlay" /&gt;
          &lt;/android.support.design.widget.CollapsingToolbarLayout&gt;
      &lt;/android.support.design.widget.AppBarLayout&gt;
  
      &lt;include layout="@layout/content_scrolling"/&gt;
  
      &lt;android.support.design.widget.FloatingActionButton
          android:id="@+id/fab"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_margin="@dimen/fab_margin"
          app:layout_anchor="@id/app_bar"
          app:layout_anchorGravity="bottom|end"
          android:src="@android:drawable/ic_dialog_email"/&gt;
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>
  
  <p>content_scrolling.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.v4.widget.NestedScrollView
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      app:layout_behavior="@string/appbar_scrolling_view_behavior"
      tools:showIn="@layout/activity_scrolling"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      tools:context=".ScrollingActivity"&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_margin="@dimen/text_margin"
          android:text="@string/large_text"/&gt;
  
  &lt;/android.support.v4.widget.NestedScrollView&gt;
  </code></pre>