title: Material design layout_scrollFlags meanings
body: <p>I find out that we can use cool flags that scroll both toolbar and even content by using <code>layout_scrollFlags</code>. In my case, I have a layout like this:</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"&gt;
  
      &lt;android.support.design.widget.AppBarLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"&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:layout_scrollFlags="snap"
              app:popupTheme="@style/ThemeOverlay.AppCompat.Light" /&gt;
  
          &lt;android.support.design.widget.TabLayout
              android:id="@+id/tabs"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              app:tabMode="fixed"
              app:tabGravity="fill" /&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;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>
  
  <p>one of my tabs is a <code>fragment</code> and its layout has a <code>Recycle View</code> with a <code>edittext</code> below the RecycleView. firstly I wanna know what this flag means  </p>
  
  <p>google says:</p>
  
  <ul>
  <li><strong>SCROLL_FLAG_ENTER_ALWAYS</strong><br>
  When entering (scrolling on screen) the view will scroll on any downwards scroll event, regardless of whether the scrolling view is also scrolling. </li>
  <li><strong>SCROLL_FLAG_ENTER_ALWAYS_COLLAPSED</strong><br>
  An additional flag for 'enterAlways' which modifies the returning view to only initially scroll back to it's collapsed height. </li>
  <li><strong>SCROLL_FLAG_EXIT_UNTIL_COLLAPSED</strong><br>
  When exiting (scrolling off screen) the view will be scrolled until it is 'collapsed'. </li>
  <li><strong>SCROLL_FLAG_SCROLL</strong><br>
  The view will be scroll in direct relation to scroll events. </li>
  <li><strong>SCROLL_FLAG_SNAP</strong><br>
  Upon a scroll ending, if the view is only partially visible then it will be snapped and scrolled to it's closest edge. </li>
  </ul>
  
  <p>I changed this flag randomly and in some cases my edit text went away till I scrolled the toolbar up and then edit appeared. I read google documents
  but I could not get it well. I want to understand it in simple terms.</p>