Incorrect behavior in iOS 8.1

[ryanmeisters]

It looks like this category is behaving incorrectly under iOS 8.1. This can be seen in the example project.

Incorrect behavior:

• All test views are snapping back to their original positions immediately upon touching the drop view.
• View 2 is returning to its starting position when dragging ends.

Correct behavior:

• Test views 1, 3, 4 should return to their starting positions (animated) when dropped (on the drop view or not), but only when dropped.
• View 2 should not return to it's starting position.

I will see if I can get some time to look more closely at this.

[slangley]

So I looked into this quite a bit, and figured out that it was due to the UILabel's being changed in the middle of the delegate calls.

For some reason in iOS 8, Apple modified behaviour of UILabel such that when you change the text of a label, the constraints for it's superview are updated. Likely due to content hugging, size changes, etc.

Since we are dragging the UIView around without updating the constraints, as soon as the constraint system kicks in and updates, the view that is being dragged reverts back to it's original position.

[mps]

@ryanmeisters @slangley did you all ever make any progress on this behavior in iOS 8.1+? Thanks!

[slangley]

The behaviour works in 8.1 as long as you don't do something mid drag that forces a constraint update. The sample updates the label in the middle of the drag that forces a re layout, causing the view being dragged to have its frame reset.

I have used this category successfully in an app which is fully auto layout based by ensuring I am avoiding the above caveat.

App is here and is drag heavy:
http://itunes.apple.com/ca/app/gummii/id669982848?mt=8

On Apr 23, 2015, at 8:59 AM, Matthew Strickland [email protected] wrote:

@ryanmeisters @slangley did you all ever make any progress on this behavior in iOS 8.1+? Thanks!

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