Re: How to do smooth scrolling on browser back/next button on same-page navigation?

I wouldn't recommend disabling the back/next behavior. For your case, you could save the scroll position of each View (using a ScrollHandler to catch the events), and when the History is changed, scroll to the current View position (or to the top if the View is a new one) using Window.moveTo, or another method from your library.

Something like this:

private Map<String, Point> scrollPositions = new HashMap<>();

Window.addWindowScrollHandler(new Window.ScrollHandler(){
    @Override
    public void onWindowScroll(Window.ScrollEvent event){
        scrollPositions.put(History.getToken(), new Point(event.getScrollLeft(), event.getScrollTop()));
    }
});

History.addValueChangeHandler(new ValueChangeHandler<String>(){
    @Override
    public void onValueChange(ValueChangeEvent<String> event){
        Point p = scrollPositions.get(event.getValue());
        if (p == null) p = new Point(0,0);
        Window.moveTo(p.getX(), p.getY()); //or something else from your lib
    }
});

For a library to handle History tokens and page navigation that a look at this post. ;-)

On Tuesday, May 5, 2015 at 8:51:25 AM UTC-3, Ed wrote:

I have a sticky top menu with menu items that perform smooth scrolling (through GreenSock) to a certain page location (I stay on the same page all the time).

It will also add a History token for every unique page location.

That works fine, it scrolls smooth and the back/next browser buttons work "well".

However, no smooth scrolling occurs when the back/next browser buttons are used as the browser will jump to the previous location immediately, before even History.onHasChanged() is called (detected through a breakpoint) :(

In my History handler I calculate the required scrolling distance, which is zero because the browser already jumped (scrolled) to the previous page location.

How can I perform the smooth scrolling when the browser  back/next buttons are used?

Is there any way, to disable this browser behavior? (cancel the browser back/next event), or replace the browser back/next behavior?

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