Fix scroll up not propagating to parent

[Jacquelin]

Hello,

This pull request is to fix, what I consider a bug, the issue #3340

This 'bug' happen for a grid that displays less than its height (3 line, 3 * 30px, for a height of 300px for example). When this happening, the scroll up is not propagated to the parent.

I assumed that if the VerticalScrollLength AND the scrollTop + scrollYAmount is negative, then the scrollYPercentage is set to 0.

It's working for a grid with the vertical scroll avalaible, or not.

[PaulL1]

@swalters: any chance you'd take a quick look at this one too? It looks sort of OK in concept, but I know there are gremlins hiding in scrolling code.

[Jacquelin]

Hi,

I think of another possibility, "rowContainer.getVerticalScrollLength();" could be an absolute value (never negative!). It solve the bug too. If you think it's a better solution, you can just reject the PR and I will make an another PR with the absolute value

thx

[rupampatel2006]

@Jacquelin Your fix works well. @PaulL1 Are you going to merge this fix?

[PaulL1]

@rupampatel2006 : not without @swalters reviewing it.

[Jacquelin]

Hi,

no news from @swalters ?

[villelahdenvuo]

I would really like this to get fixed, not being able to scroll up at all on my page with a full width grid.

[Jacquelin]

Sorry but my pull request does not fix the scroll issue ...

I make several test :

• With no scroll needed
  • For this case, my fix seems enough
• With scroll but VerticalScrollLength < 0 (http://plnkr.co/edit/Xoianpl2wWSKuQVtuxOt?p=preview)
  • Does not work !
• With scroll and VerticalScrollLength > 0
  • Work fine

This PR should be rejected, I'm currently working on a better fix ... sorry :-/

[villelahdenvuo]

I think the main issue for me is that, even though I have set enableVerticalScrollbar: uiGridConstants.scrollbars.NEVER and I resize the grid to the contents it still eats the scroll event.

[Jacquelin]

@tuhoojabotti : It's what I was trying to fix in first place (my fix work for this !), but still ... incomplete for a true bug fix. You can discuss about this at #3340