GXT remove iframe

IframeReferenceSandbox.java

package com.sencha.gxt.test.client._northgate;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.IFrameElement;
import com.google.gwt.dom.client.NodeList;

public class IframeReferenceSandbox implements EntryPoint {

  protected static class IFrameElementExt extends IFrameElement {
    protected IFrameElementExt() {
    }

    public final native JavaScriptObject getWindow() /*-{
      return this.contentWindow;
    }-*/;
    
    public final native void clear() /*-{
      this.src = '';
//      this.contentWindow.document.write('');
//      this.contentWindow.close();
    }-*/;
  }
  
  @Override
  public void onModuleLoad() {
    
    NodeList<Element> iframes = Document.get().getElementsByTagName("iframe");
    
    if (iframes != null) {
      for (int i=0; i < iframes.getLength(); i++) {
        GWT.log("iframe " + i);
        
        // option 1
//        IFrameElement iframe = iframes.getItem(i).cast();
//        iframe.setSrc("about:blank");
//        
//        Document document = iframe.getContentDocument();
//        document.removeAllChildren();
//        
//        Document.get().removeChild(iframe);
        
        // option 2
        IFrameElementExt iframe2 = iframes.getItem(i).cast();
        iframe2.clear();
        iframe2.removeFromParent();
      }
    }
    
  }

}