UIScrollView and its subclasses won't bounce if nested in custom UIView

Originator:nskboy
Number:rdar://8045239 Date Originated:31-May-2010 05:48 PM
Status:Open Resolved:
Product:iPhone SDK Product Version:3.1.3/10M2148
Classification:Other bug Reproducible:Always
 
31-May-2010 05:48 PM Roman Busyghin:
Summary:
UIScrollView and its subclasses won't bounce if they are nested into custom UIView. Scroll view starts bouncing when it is nested into plain UIView.

Steps to Reproduce:
1. Run the attached sample code and try to make scroll view bouncing by dragging it to the one of its edges

Expected Results:
UIScrollView should bounce normally

Actual Results:
It won't bounce

Regression:
Problem exists in both 3.1.3 and 4.0. To workaround this problem you should put additional UIView between custom UIView and your UIScrollView.

Notes:

Comments

Also saved me lots of time!

By dustinpaystaxes at June 6, 2011, 2:45 a.m. (reply...)

Better solution

The underlying problem here is if you set the scrollview's frame/bounds in -layoutSubviews, it doesn't check if you're setting it to the frame/bounds that it already has, and this cancels the bounce. The solution is to do something like

CGFrame scrollFrame = [self calculateFrameForScrollView]; if (!CGRectEqualToRect(scrollFrame, self.myScrollView.frame)) { self.myScrollView.frame = scrollFrame; }

By kballard at July 2, 2010, 1:15 a.m. (reply...)

I wish I found this earlier

Many thanks!

I tried to solve my problems with scroll view for about 12 hours before found this. Worked like a charm.

By sergius.bobrovsky at Sept. 1, 2011, 10:43 a.m. (reply...)

Thanks again!

Just wanted to also say thanks - this tip saved me an otherwise inevitable headache and long frustrating debugging process.

By danbretl at Dec. 22, 2010, 10:52 a.m. (reply...)

Thank you kballard!

It works perfectly for me.

By nskboy at July 13, 2010, 9:24 p.m. (reply...)

Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at bugreport.apple.com before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!