Thank you Eric.
The user's guide is more on explaining each features and it only have 2 example tutorials. Does it have more examples to learn?
Like traditional languages, VB, Delphi, etc, the IDE is very easy to do drag and drop and very fast to generate a prototype, whereas GWT needs a thorough understanding on how one component connect to another. We cannot simply drag and drop on the canvas. It makes me struggling to create a prototype in my company project now.