GWT 2.1 Places & Activities – What changed between M3 and RC1

If you've started using GWT 2.1 Places and Activities with the Milestone 3, then here's what changed in the Release Candidate 1. I'll update my previous articles in the coming days to reflect those changes.

• The com.google.gwt.app.place package has been split into the com.google.gwt.place and com.google.gwt.activity.
• Activity.Display now is com.google.gwt.user.client.ui.AcceptsOneWidget, which is implemented by SimplePanel (showActivityWidget is thus renamed as setWidget).
• IsWidget has been moved to com.google.gwt.user.client.ui and is now implemented by Widget (which returns itself); this means that if your view classes extends Widget (most views extend it through Composite) you no longer have to implement the asWidget method.
• In addition, all widgets now accept IsWidget as argument where they already accepted Widget.
• HandlerManager is @Deprecated and no longer implements EventBus; you'll now use a SimpleEventBus for your application-wide event bus.
• PlaceHistoryHandler has been split into a concrete PlaceHistoryHandler and the PlaceHistoryMapper interface, which you're free to implement yourself or use as before, giving your sub-interface to GWT.create() so that it generates the implementation from the @WithTokenizers annotation (and/or factory if you're using PlaceHistoryMapperWithFactory); this approach is similar to the ActivityManager vs. ActivityMapper, with the added generator for the mapper based on PlaceTokenizers and @Prefix.
• The ProxyPlace, ProxyListPlace and associated classes (and abstract activities) have been moved to the Expenses sample (which doesn't use them yet).

And this list is only about the Places and Activities part: RequestFactory's API has been deeply refactored, and a new Editor module is born!