SizeClassAwareness

This UIViewController extension adds the ability to set constraints based on the TraitCollection:

Installation

SizeClassAwareness is available through Carthage or CocoaPods.

Carthage

To install SizeClassAwareness with Carthage, add the following line to your Cartfile.

Swift 3.0.x

github "Lutzifer/SizeClassAwareness"

Then run carthage update --no-use-binaries command or just carthage update. For details of the installation and usage of Carthage, visit its project page.

CocoaPods

To install SizeClassAwareness with CocoaPods, add the following lines to your Podfile.

Swift 3.0.x

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '9.0'
use_frameworks!

pod 'SizeClassAwareness'

Then run pod install command. For details of the installation and usage of CocoaPods, visit its official website.

Example

// For Horizontally Regular, GreenView is in lower-leading corner
let leadingConstraint = self.greenView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor)
let bottomConstraint = self.greenView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor)

self.insertConstraint(leading, horizontally: .regular)
self.insertConstraint(bottomConstraint, horizontally: .regular)

// For Horizontally Compact, GreenView is in upper-trailing corner
let topConstraint = self.greenView.topAnchor.constraint(equalTo: self.view.topAnchor)
let trailingConstraint = self.greenView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor)

self.insertConstraint(topConstraint, horizontally: .compact)
self.insertConstraint(trailingConstraint, horizontally: .compact)

To automatically update the constraints when the traitCollection changes, just call self.activateConstraintsBasedOnTraitCollection() in traitCollectionDidChange:

  override open func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
    super.traitCollectionDidChange(previousTraitCollection)
    self.activateConstraintsBasedOnTraitCollection()
  }