Everything is based on the Browser Form control that loads map.html:

address:before(3):-oxy-edit-gps {
    display:block;
    content: oxy_browser(
                    href, oxy_url("map.html"), 
                    width, 100%, 
                    height, 400px
                    );
}

The HTML loaded by this form control uses Google Maps to presents the coordinates:

    //--------------------------------------------------
    // Initializes the map on the given coordinates.
    //--------------------------------------------------
    function initialize(lat, lng) {
        
        var latlng = new google.maps.LatLng(lat, lng);
        var myOptions = {
            zoom: 15,
            center: latlng,
            mapTypeId: google.maps.MapTypeId.ROADMAP,
            // mapTypeId : google.maps.MapTypeId.HYBRID,
            mapTypeControl: false,
            navigationControl: false,
            streetViewControl: false
        };
        
        document.map = new google.maps.Map(document.getElementById("map"), myOptions);
    }

The interaction between the Javascript and the Oxygen Workspace is possible through a number global variables visible in Javascript:

• authorAccess- this object is an instance of an ro.sync.ecss.extensions.api.AuthorAccess.
• contextElement - an instance of an ro.sync.ecss.extensions.api.node.AuthorNode. The form control is added over this node.
• pluginWorkspace- an instance of an ro.sync.exml.workspace.api.standalone.StandalonePluginWorkspace.
• fcArguments - a java.util.Map implementation tith the property name - property value pairs put on the form control function.
• apiHelper - A helper object for creating Java objects. These objects can afterwards be passed as arguments when calling Oxygen's Java API.

 var newAttrValue = apiHelper.newInstance(
           "ro.sync.ecss.extensions.api.node.AttrValue",
           ["normalizedValue", "rawValue", true]);
 authorAccess.getDocumentController().setAttribute(
        "counter", newAttrValue, contextElement);

Please see map.html for the full version.