title: Android scrollview onScrollChanged
body: <p>I have a fixed content in my text view inside a scroll view. When the user scrolls to a certain position, I would like to start an activity or trigger a <code>Toast</code>.</p>
  
  
  
  <pre><code>&lt;ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent" android:layout_height="fill_parent"
   android:id="@+id/scroller"&gt;
   &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent"&gt;
    &lt;TextView android:layout_width="fill_parent" android:id="@+id/story"
     android:layout_height="wrap_content" android:text="@string/lorem"
     android:gravity="fill" /&gt;
   &lt;/LinearLayout&gt;
  &lt;/ScrollView&gt;
  </code></pre>
  
  <p>My problem is in implementing the protected method <code>onScrollChanged</code> to find out the position of the scroll view.</p>
  
  <p>I have found <a href="https://stackoverflow.com/questions/3948934/synchronise-scrollview-scroll-positions-android">this</a> answer, is there an easier solution to this rather than declaring an interface, over ride the scrollview etc as seen on the link I posted?</p>