scrollVerticallyToOffset doesn't work

[yingogobot]

Hello,

I was recently using your scroll view, i like it very much, but there is one thing i would like to know that scrollVerticallyToOffset seems like not working.

And i was also tried to use something like
[_glassScrollView.foregroundScrollView setContentOffset:CGPointMake(0, 200) animated:YES];

doesn't work either, would you mind take a look at it, i don't know if that's a bug or not.

Thanks,

YinBot

[yingogobot]

I think i found the issue, when we call
[_glassScrollView scrollVerticallyToOffset: 300];

it will trigger the view controller to call - (void)viewWillLayoutSubviews again.

And in your example, you have
[_glassScrollView setTopLayoutGuideLength:[self.topLayoutGuide length]];
in the viewWillLayoutSubviews, setTopLayoutGuideLength will change the content size of _foregroundScrollView, which cause the setContentOffset is ignored.

Maybe we want to put [_glassScrollView setTopLayoutGuideLength:[self.topLayoutGuide length]];
in view did load.

[BTLibrary]

Thanks for reporting a bug. I don't quite understand the problem. Is that in my example? If not, would you mind provide a snippet of what you had? I am uploading a newer version of this with better example. It might fix the bug but let me know. Thanks!

[yingogobot]

Hi it's not in your example, but i found in the header file, there is a method call

• (void)scrollVerticallyToOffset:(CGFloat)offsetY;

I was trying to use that method
such as [_glassScrollView scrollVerticallyToOffset: 300];
but unfortunately that methods doesn't do anything.

[BTLibrary]

To my knowledge, calling scrollVerticallyToOffset should not trigger viewWillLayoutSubviews. If you look into BTGlassScrollView.m you will see it only offset the scrollView. That alone cannot cause viewWillLayoutSubviews. Please confirm that your code do not have anything else to do with calling viewWillLayoutSubviews. In my original example, I use it in the scrollViewDidScroll delegate method and it works really well.