What does “Constrain to margins” mean in Interface Builder in Xcode 6.0.1

12
votes

I understand the purpose of "Spacing to the nearest neighbor" (in Xcode 6, more especially in Interface Builder) but what is the point of "Constrain to margins"?

Is there a link between "Spacing to the nearest neighbor" an edge of a particular control button, and the fact of at the same time checking the checkbox named "Constrain to margins"?

What is the role of this feature in Autolayout?

Please find a screenshot with the checkbox and the label that I am talking about surrounded in red below:

Constrain to margins screenshot

(Screenshot above in bigger format)

Thank you in advance for your answers to my three questions.

1
swiftinterface-builderautolayoutxcode6margins
possible duplicate of What is "Constrain to margin" in Storyboard in Xcode 6 – Lord Zsolt
I have checked the link of the post but the best explanation is: "in iOS 8 you now have the option to define your constrains relative to a predefined margin to the superview's bounds, instead of the superview's bounds themselves.". Sorry but it is not clear and does not mean anything for me, that is why I ask to clarify this obscure answer and explanation. – King-Wizard

1 Answers

22
votes

iOS8 introduces a new property of the UIView: layoutMargins. Shortly: these 4 values (a UIEdgeInsets) represent the margins of the view: its subviews can now be positioned relative to these margins, or the old way relative to the sides. I wrote an article about this in my blog with more details, let me know if it is clear and if you have additional doubts.