Fix bug scroll (up and down) does not propagating to parent

[Jacquelin]

Hello,

This pull request is to fix the issue #3340.

My first pull request #3531 was not good enough.

Now, I only check if the Vertical scroll length is negative. If it is, then I let the parent the parent container scroll.

Sorry for this double Pull request ...

[PaulL1]

Thanks for the contribution.

My concern is that I'm not sure that getVerticalScrollLength should be returning < 0, so there's a risk that someone will fix that, and thereby break this again.

Also, if we were to merge it we'd need the three commits squashed into one.

@swalters, do you have an opinion?

[Jacquelin]

PaulL1 said :

My concern is that I'm not sure that getVerticalScrollLength should be returning < 0, so there's a risk that someone will fix that, and thereby break this again.

You are right. So I test some code fix with getVerticalScrollLength as an absolute value. This fix some scroll but not all. I try with getVerticalScrollLength === 0, but same, it's fix some scroll but not all ... Waiting for @swalters response

Also, if we were to merge it we'd need the three commits squashed into one.

For this I don't know how I can do it ...

Thanks for the contribution.

it's a pleasure ;-)

[PaulL1]

@Jacquelin: thanks for the input, we'll wait for @swalters to see what he can tell us.

On the squash, the basic process is to issue git rebase -i upstream/master, this will take you into an interactive process in which you can tell git to squash all your commits into a single commit, and rewrite the commit message that goes with that. You then git push -f to force the remote to take the rewritten commit log.

[Jacquelin]

Thank you for the squash !!!!!! ;-)

[swalters]

@Jacquelin I have to agree with @PaulL1 . What should be fixed is the ScrollEvent.AtTop and .AtBottom. Those should both return true if the grid is truly at top and/or bottom row.

[Jacquelin]

@swalters Oki !

But how can I fix it ?

When rowContainer.getVerticalScrollLength() < 0, So the 'y.percentage' is mixed (or reverse). and this make :

// When on top : this.y.percentage === 1, then atTop return false.
ScrollEvent.prototype.atTop = function(scrollTop) {
  return (this.y && this.y.percentage === 0 && scrollTop === 0);
};

// When on bottom : this.y.percentage === 0 so atBottom return false
ScrollEvent.prototype.atBottom = function(scrollTop) {
  return (this.y && this.y.percentage === 1 && scrollTop > 0);
};

What do you think if I set the scrollYpercentage before call atTop/Bottom ?

// Keep scrollPercentage within the range 0-1.
if (rowContainer.getVerticalScrollLength() < 0) {
  if (scrollTop > 0) { scrollYPercentage = 1; }
  else { scrollYPercentage = 0; }
}
else if (scrollYPercentage < 0) { scrollYPercentage = 0; }
else if (scrollYPercentage > 1) { scrollYPercentage = 1; }

[swalters]

I made a comment in #3690 I think we'll go that direction for the fix. Thanks for the PR