Force re-measurement of scrollbars

[nickfogler]

Use case is the parent container of my SlickGrid instance is hidden during instantiation, so scrollbar measurement is returning {width: 0, height: 0}. Need a way to force a re-measurement after parent container is visible. There might be a better place than this to do so...?

[ghiscoding]

It looks like the only reason you've added the code change is because measureScrollbar function is not exported. Isn't it easier to just export measureScrollbar as public? Unless you really need the call the resizeCanvas() for some other reasons?

[nickfogler]

I don't need the result of measureScrollbar() exported - that's already available with getScrollbarDimensions(). I need the value of scrollbarDimensions to be updated internally, so the other internal functions that use that value will be updated (and then force the canvas to redraw taking into account the correct scrollbar values).

[6pac]

Apologies for not using this PR, it was the list of commits that put me off - just creates a lot of noise in the commit list.
I have made the following change, which will have the same net effect:

  if (!scrollbarDimensions || !scrollbarDimensions.width) {
    scrollbarDimensions = measureScrollbar();
  }

This is committed to the repo but I haven't issued a new release yet.