title: How To Implement Scroll Listener In Vaadin 7 Tables
body: <p>In Vaadin, when you scroll down or up in tables (<strong>com.vaadin.ui.Table</strong>) there is no event that will be fired to tell you that user is now scrolling.</p>
  
  <h3>Why would we need scroll event in table?</h3>
  
  <p>Let's first take a look at this example of Vaadin (<a href="http://demo.vaadin.com/dashboard/#!/transactions" rel="nofollow">Dashboard Demo</a>) after you open the link just click sign in, and you'll be automatically redirected to the transactions page, this page shows a table of financial transactions, these transactions will show a batch after another while you are scrolling, what actually happened is that the data was loaded on UI initiation (all the transactions).</p>
  
  <p>Now, let's assume that we have thousands or say millions of transactions. Is it logic to load them all together when the UI is initiated? isn't it of wisdom to load them bit by bit to prevent slowing down the UI while it waits for all transactions to load?.</p>
  
  <p>The best solution to this problem is to get the first (say 100 transactions) then get more transactions while scrolling down, but this solution have only one <em>problem</em>, that is Vaadin does not support <strong>Scroll Event Handling</strong> in <strong>com.vaadin.ui.Table !! </strong></p>