title: React/ES6 Onscroll function not triggering in Y direction
body: <p><br/><strong>Reference</strong> <a href="https://i.stack.imgur.com/59LLe.png" rel="nofollow noreferrer">image of Scroll bar</a></p>
  <br/>
  <p>I have created a web application in which I need value of scrollTop. Changing the overflow property I got to know that Y-axis scrolling is occur from <em><strong>index.js</strong></em> file. Scroll bar in X-axis occur from <em><strong>SUB COMPONENT</strong></em> created by me  and its parent is rendered in <em><strong>App.js</strong></em>.</p>
  <br/>
  <p>I have created scroll event handler in <em><strong>index.js</strong></em>. which is getting triggered only for X-axis scrolling which is occuring from sub component but not triggering for Y-axis scrolling.</p>
  <br/>
  <p>Can anyone help me out here please to get scrollTop value.</p>
  <br/>
  <p>Folder Structure:
  <br/>
  <br/>
  <em><strong>index.js</strong></em>  (Y-axis scroll bar is formed due to this javascript file, I need scrollTop value by scrolling this, created scroll event here which is not triggering for this)<br/>
  <em><strong>App.js</strong></em>
  <br/>
  <em><strong>components folder</strong></em>
  <br/>
            |<br/>
            |<br/>
            <em><strong>component.js</strong></em><br/>
            <em><strong>sub component folder</strong></em><br/>
                      |<br/>
                      |<br/>
                      <em><strong>subComponent.js</strong></em> (X-axis scroll bar is formed due to this javascript file, scroll event handler created in <em><strong>index.js</strong></em> is triggered from this)<br/><br/>
  Thanks in advance :)</p>