Layout Best Practices

Read of the day while you’re nervously waiting to see what will need panic rewrites tomorrow:

Screen Shot 2014-09-08 at 8.33.11 AM.png

Don’t think there’s anything in there actually covered by NDA at this point, but we’ll just refer you there for the beta software feature discussion bits. The important parts are not new, but they’ve been widely disregarded to date, at least they sure are in software we get stuck maintaining:

  • Nowhere should you be using screen or window size to do layout. Your view bounds should be the only consideration.
  • At load time, as called out above, you’re not in a hierarchy yet. Therefore you do not know what your view bounds will be. This has always been a thing for any view contained by a view with its own layout, and became more of a thing with iOS 7 when your views developed an inclination to jump under the status bar behind your back, but rumour has it that it will be a big thing very soon.
  • layoutSubviews is the best place to be putting your legacy-type frame setting code.
  • updateViewConstraints is the correct place to figure out your interface for reals; if you’ve so far avoided auto layout, now is a superb time to get on that.

Hopefully none of this is any particular news to you, so getting all those legacy codebases copacetic with whatever novel execution environments actually appear tomorrow from the collection of swirling rumours should be no problem, right?

Alex | September 8, 2014

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