How to mask the application in with GXT 3.0 - gwt

Question

I've been developing using GWT 2.3.0 and GXT 2.2.5. I was finally able to move up to GWT 2.4.0 and decided to look into what it would take to migrate to GXT 3.0, but right off the bat I hit a snag.
The application does a lot of blocking the user by masking the browser. I use the following commands to do so:
XDOM.getBodyEl.mask();
XDOM.getBodyEl.unmask();
First thing I noticed was that in 3.0, XDOM no longer has the getBodyEl() method, so I have no way of retrieving the top document widget from anywhere in the application. I do see there is now a Mask class, but since it requires an element parameter to work, I'm still in need of a reasonably easy way to get the document body element.
I've tried searching through the Sencha forums with no success. Any suggestions as to how I could do this?

Answer 1

This is one of those good news/bad news situations. The good news is that El is gone, no more confusion with when to wrap, when to El.fly, when to save a reference, etc. More good news: the new version is called XElement, and to turn an Element into an XElement, you simply cast (either java cast or jso .cast()):
Element elt = ...;
XElement oneWay = elt.cast();
XElement theOtherWay = (XElement) elt;
Either way works, no overhead. All the magic of El, with none of the confusion.
Except for the bad news. But first, some additional good news:
This change is part of a bigger strategy to try to do things The GWT Way, simplifying how many guides are needed to do anything, and getting rid of some of the duplication that GXT does of existing GWT features. Most of that duplication makes sense either when you look at how GWT has grown over the years, and the rest usually make sense when GXT needs a little more power than what GWT offers (layout panels vs layout containers, RootLayoutPanel vs Viewport, HasData vs Stores, etc). Other areas where GXT is now using GWT stuff: HTML, Label widgets, SafeHtml and other string formatting (except XTemplates, which is SafeHtmlTemplates plus awesome), supporting RPC/RequestFactory/anything-else-that-looks-like-an-object, the Cell API, the Editor framework, etc.
Bad news:
Now that it is Just That Easy to get an XElement out of anything, most of the convenience methods to transform things into El objects are gone too. XDOM is still there, but it only does a few things now, mostly things that DOM or Document can't do for whatever reason (side note: GWT's DOM class is at least half deprecated now and may be going away in GWT 3 or so).
So, when you get the dom element that you want to do something with (like mask), you have to cast it first. In the case of your body element masking, this will look a little like this in GXT 3:
Document.get().getBody().<XElement>cast().mask("Loading...");//or null if you don't want text
You could also grab the Mask class and do it that way (this time with a java cast to demonstrate that its all the same):
Mask.mask((XElement) Document.get().getBody(), "Loading...");