title: Tableviewer validation in WIzardPage
body: <p>In my eclipse rcp application, I use a Wizard in which one of the WizardPage uses a TableViewer component. There are 2 columns in the tableviewer and I have enabled <code>EditingSupport</code> for one of the column. My requirement is to validate the values entered in the editable columns so that none should be spaces. Also I need to do the validation only after the user has finished editing all the rows. I tried various approaches. But none seem t be working.</p>
  
  <ol>
  <li>I tried finding listeners on the Table element and the Tableviewer element but with no luck(I tried <code>FocusListener</code>on the Table and <code>SelectionChangedListener</code>on TableViewer)</li>
  <li>I tried using <code>canFlipToNextPage()</code> overriden method of the WizardPage as suggested by one of the articles on the eclipse page but that too seem to be of little help. the problem with this approach is that <code>canFlipToNextPage()</code> is called by the platform even before the page is shown</li>
  <li>I get the same result as #2 when using <code>getNextPage</code> overridden method of either the wizard or the wizard page</li>
  </ol>
  
  <p>Could anyone point me to the right way of doing this? </p>