/*
 * Ext GWT 2.2.4 - Ext for GWT
 * Copyright(c) 2007-2010, Ext JS, LLC.
 * licensing@extjs.com
 * 
 * http://extjs.com/license
 */
package com.extjs.gxt.ui.client.widget;

import com.extjs.gxt.ui.client.core.XDOM;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.RootPanel;

/**
 * Wraps the document element and provides the ability to listen for document
 * events.
 */
public class Document extends Component {

  private static Document instance;

  private Document() {

  }

  @Override
  public void onBrowserEvent(Event event) {
    // do not unnessecarily create component events
    if (hasListeners()) {
      super.onBrowserEvent(event);
    }
  }

  /**
   * Returns the singleton instance.
   * 
   * @return the document
   */
  public static Document get() {
    if (instance == null) {
      instance = new Document();
      instance.setElement(XDOM.getDocument());
      ComponentHelper.doAttach(instance);
      RootPanel.detachOnWindowClose(instance);
    }
    return instance;
  }

}