title: Simple GWT Editor Example
body: <p>I'm finding anything other than copying and pasting existing GWT Editor examples to be frustrating.  Here's an attempt to create a minimal Editor, without success.</p>
  
  <pre class="lang-java prettyprint-override"><code>public class ContactEditor extends Composite implements Editor&lt;Contact&gt; {
  
      interface Binder extends UiBinder&lt;Widget, ContactEditor&gt; {}
  
      interface ContactEditorDriver extends
          SimpleBeanEditorDriver&lt;Contact, ContactEditor&gt; {}
      private final ContactEditorDriver editorDriver;
  
      @UiField TextBox salutation;
  
      public ContactEditor(Contact contact) {
          editorDriver = GWT.create(ContactEditorDriver.class);
          editorDriver.initialize(this); 
          editorDriver.edit(contact);
  
          initWidget(GWT.&lt;Binder&gt; create(Binder.class).createAndBindUi(this));
      }
  }
  </code></pre>
  
  <p>When this is instantiated with</p>
  
  <pre class="lang-java prettyprint-override"><code>ContactEditor contactEditor = new ContactEditor(new Contact());
  </code></pre>
  
  <p>I get an <code>UmbrellaException</code> that contains </p>
  
  <pre><code>Caused by: java.lang.NullPointerException: null
      at ...ContactEditor_SimpleBeanEditorDelegate.attachSubEditors(ContactEditor_SimpleBeanEditorDelegate.java:12)
      at com.google.gwt.editor.client.impl.AbstractEditorDelegate.initialize(AbstractEditorDelegate.java:264)
      at com.google.gwt.editor.client.impl.SimpleBeanEditorDelegate.initialize(SimpleBeanEditorDelegate.java:32)
      at com.google.gwt.editor.client.impl.AbstractSimpleBeanEditorDriver.edit(AbstractSimpleBeanEditorDriver.java:45)
      at ...ContactEditor.&lt;init&gt;(ContactEditor.java
  </code></pre>
  
  <p>What's going on here---SubEditors?  The failure seems to be in generated code and is hard for me to debug.</p>
  
  <p>Much thanks.</p>