title: GWT: Adding a value change listener to EditTextCell widget
body: <p>I want to do validation for <code>EditTextCell</code> widget in the grid. So I am trying to extend the <code>EditTextCell</code> and add a value change listener to the same, so that I can continue with the validation. But I am unable to add the same. Any help would be appreciated. Am using GWT 2.4.0</p>
  
  <p>My code looks like this.</p>
  
  <pre class="lang-java prettyprint-override"><code>public class MyEditTextCell extends EditTextCell { 
          public MyEditTextCell() { 
              super(); 
              onValueChange( new ValueChangeHandler&lt;String&gt;() { 
                  @Override public void onValueChange( ValueChangeEvent event ) { 
                      Window.alert( "jsdfk" ); 
                  } 
              } ); 
          } 
          private void onValueChange( ValueChangeHandler&lt;String&gt; valueChangeHandler ) { 
              Window.alert( "jsdfk" ); 
          } 
      }   
  </code></pre>