How to get list grid width that also include horizontal scrolling space

Hi there, I am currently using smartGWT 2.5 and have an issue to get the list grid width when the horizontal bar appeared.

Here is my usage:
I have a VLayout that host a ListGrid with Overflow set to Auto. Both elements have their width set to 100%.

The main ListGrid support expansion component and the expansion component also have the width set to 100%.

When I adjust some fields in the ListGrid over the window width, it caused an overflow and the horizontal scrolling bar will now be shown. However, the expansion component width won't be updated and continue to stick to the 100% windows size, hence when I am scrolling to the right, the List Grid will have some fields but the expansion component not going able to follow up.

I tried to update the expansion component width whenever the ListGrid receive a view state change (when a field width is changed), however I wasn't able to get the correct width on the ListGrid that also include the width of the scrolling bar.

I have tried both getWidth + getScrollWidth for both VLayout and ListGrid, but both of them unable to return me the width value I want.

Can you provide advice on what can I do to achieve my goal?

Edit: Attached screenshot for better explanation. The red box part is the misaligned space that I wish to retrieve. Is there any way I able to get the full width from the horizontal scrolling bar space?

Thank!

Best Regards,
Striky

Attached Images

smartgwt_2.PNG (17.5 KB)