UITableView Section headers leading/trailing margins change when offscreen.

Originator:ltupps
Number:rdar://29013952 Date Originated:29/10/2016
Status:Open Resolved:
Product:UIKit Product Version:10.0
Classification: Reproducible:always
 
Summary:
A UITableView with section headers will have the leading/trailing layoutMargins changed to 8px when offscreen. 
This is particular noticeable when you have a layout that is aligned to the leading/trailing margins views which are preserving the layout margins of the superview. Initially it will be 16px (20px on iPhone 6/7+), but when a view is scrolled offscreen it will be reset to 8px.

Steps to Reproduce:
1. Run project in TableViewBug.
2. Scroll down so that section headers are off screen.
3. Scroll up so that section headers reappear. 
4. The headers will now have leading/trailing margins of 8 pixels instead of 16/20px

Expected Results:
Trailing/Leading Margins should remain the same. 

Actual Results:
Trailing/Leading Margins changes to 8 pixels after being offscreen. 

Version:
10.0.2 / Xcode 8.0/iOS 10 Simulator

Notes:


Configuration:
Simulator, iPhone 6, iPhone 7+

Comments


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