That is a great question.
The official response I've heard is they are looking for the community to provide and currently the gwt-google-maps-v3 is the most complete project so referrals have been pointing to it.
I agree, I rather develop my apps with GWT and that is why I've decided to write the Maps V3 GWT api.
I'm not sure I know all the correct words for this. But heres my take on why I'm writing V3.
1. gwt-google-maps-v3 is written in V2's (overlay/implementation) model, which is outdated in my opinion. I remember Eric saying it would be better to move to the new Overlay format too, at least I think that's what he meant. It's been some time since I've asked. I think the GWT 2.0+ has [JavaScriptObject] Overlays work better. Due to that, I felt creating a new project was necessary.
2. I want to use the EventBus for events so HandlerRegistration in the widget needed to be used. I wanted to use the core event system. For instance events. This simplies things b/c its
// handler for mapWidget
public HandlerRegistration addClickHandler(ClickMapHandler handler) {
return MapHandlerRegistration.addHandler(impl, MapEventType.CLICK, handler, new ClickEventFormatter());
}
// handler being used
LatLng center = LatLng.newInstance(49.496675,-102.65625);
MapOptions opts = MapOptions.newInstance();
opts.setZoom(4);
opts.setCenter(center);
opts.setMapTypeId(MapTypeId.HYBRID);
mapWidget = new MapWidget(opts);
pWidget.add(mapWidget);
mapWidget.setSize("500px", "500px");
mapWidget.addClickHandler(new ClickMapHandler() {
public void onEvent(ClickMapEvent event) {
// TODO fix the event getting, getting .... I've got to come back and simplify getter... like in my FusionTables
System.out.println("clicked on latlng=" + event.getMouseEvent().getLatLng());
}
});
3. gwt-google-maps-v3 is incomplete. I'd help, but I like the new Overlay system. I aim to write every detail out. And provide access to the native JSO objects so others can extend and write JSNI to add features if needed.
4. I'd like to provide a extensive examples to write the bindings too so others can easily pick up the techniques use. I'm no expert, but I can help present more angles so others.
So far my V3 code api is working great for me. I'm getting close to source release, but I want to be sure the structure won't go through a major change, so I'm trying to wait till I have all the basics written. I'm thinking of releasing code before I write the services. Although I didn't want to generate to much fixes, bugs, namespace, directional feedback activity quite yet, which would distract from core focus of writing and writing tests to make sure things work great before release.
My overall goal is have a production ready API with regression testing so it won't fall apart on fixes.
Hope that helps,
Brandon Donnelson