java - How do I determine whether I am going "forward" or "backward" through my History in GWT?

Question

I am looking at History and History JavaDocs in GWT and I notice that there is no way to tell whether the forward or backward button was pressed (either pragmatically or by the user). The "button press" is handled by your registered addValueChangeHandler, but the only thing passed to the handler is a string on your history stack. There is no indication as to whether the "History" is moving "back" (using the back arrow button) or "forward" (using the right arrow button). Is there any way to determine this?

Answer 1

Sorry, you can't. And even if you could, there are browsers, like Firefox, that let the user "jump" back more than one page. So if you try to relying on relative "coordinates" instead of absolute, the navigation could break your app.

You can always append some kind of counter on your history token. It would not be hard, if you have only one history listener.