Questions tagged [adaptive-layout]

Technical Overview

Adaptive Layout has been available since iOS 8. Instead of specific device types, or orientations, it introduces the concept of Size Classes. A size class can be either Compact or Regular in Horizontal or Vertical directions. Additionally there is an Any size class which serves for general layout constraints.

Some examples:

• Compact Width + Regular Height represents an iPhone in portrait orientation.
• Any Width + Compact Height will apply to iPhones in landscape.

Each size class may have its custom layout, with its own set of constraints. Adaptive Layout uses a hierarchical approach to determine which rules to use:

• Any rules are used for general use: If there are no specific rules in either Horizontal or Vertical layouts, the screen will show according to these constraints. This is the perfect place for defining shared layout rules
• Use Regular or Compact to achieve custom layout rules for a specific subset of Size classes. For example, to achieve a speficic layout for iPhones in landscale mode, proper constraints must be installed in the Any Width + Compact Height size class.

To support this new approach UIKit was also extended with Trait Collections. A UITraitCollection object describes the properties of an user interface element, such as its display scale (Retina or Non-Retina resolutions), device idiom (iPhone or iPad) and its size class.

In case of any change in layout (e.g.: a rotation), developers can examine the new traits, and act accordingly. In order to support this new approach, previous rotation-focused methods have been deprecated in favor of handling transitions between different trait collections.

Where to start?

• Apple Developer: Adaptive User Interfaces
• Apple HIG: Adaptivity
• Adaptive Layout Tutorial by Sam Davies