GWT MapWidget from javascript as GMap2

I am using GWT for google map application. I use Google's gwt-maps.jar for mapping api.

I can create a map as

 private MapWidget mapId;

 if (Maps.isBrowserCompatible()) {
   mapId = new MapWidget();

   mapId.setPixelSize(600, 500);
   RootPanel.get("gmap").add(mapId);

   mapId.setCurrentMapType(MapType.getHybridMap());
   mapId.addControl(new LargeMapControl());
   mapId.addControl(new MapTypeControl());
   mapId.addControl(new ScaleControl());

   mapId.setCenter(LatLng.newInstance(-33.867139, 151.20711), 9);
  }

Now I have some legacy javascript code that needed to work on this map object. I want to use something like this:

$wnd.mapId.addOverlay(ovrlay1);

But I cannot get this $wnd.ma开发者_运维技巧pId variable. Do you know any way to get GMap2 object from existing map on some element? It will work if I get the GMap2 instance from my "gmap" div.

For the time being I am using JSNI to generate all the map functionalities. Simmilar to:

$wnd.mapId = new $wnd.GMap2($wnd.document.getElementById("gmap"));

Looks like I have to answer this by myself. The MapWidget object can return an handle to javascript object using getPeer() method. So What I need is bind a javascript object by calling getPeer. The following code do this.

private MapWidget mapId;

if (Maps.isBrowserCompatible()) {
  mapId = new MapWidget();
  nativeExportMapPeer(mapId.getPeer());
  ...
 }

 ...

 // export the native GMap2 object with a JSNI method
 private static native void nativeExportMapPeer(JavaScriptObject peer) /*-{
      $wnd.mapId = peer;
 }-*/;

Thanks Eric Z. Ayers for pointing this.