title: position absolute in react native
body: <p><a href="https://i.stack.imgur.com/XDHo5.png" rel="nofollow noreferrer">click to see design</a></p>
  
  <p>I'm having a problem positioning the white floating button on top of the blue header. The button is a TouchableOpacity inside a View which has Header and a ScrollView. How do I position the button on top of the blue header and scrollview? </p>
  
  <pre><code>&lt;View style={{ flex: 1 }}&gt;
          &lt;Header headerText={'Events'} /&gt;
          &lt;TouchableOpacity 
                  style={styles.addButtonContainerStyle}
                  onPress={ () =&gt; {Actions.addEventMain()} }
              &gt;
              &lt;Text style={styles.addButtonTextStyle}&gt;+&lt;/Text&gt;
          &lt;/TouchableOpacity&gt;
          &lt;EventList /&gt;
      &lt;/View&gt;
  </code></pre>