jbates99 / simpleavatar

Simple iOS app showing how to build a customizable avatar view using auto layout and IB Designable views.

SimpleAvatar

Simple iOS app showing how to build a customizable avatar view using auto layout and IB Designable views.

Usage

During class, we will start at the 1-class-start tag. We will talk a little about @IBDesignable, @IBInspectable, and using didSet before proceeding.

The focus of class will be understanding how to add views programatically. The bulk of our time should be spent understanding auto layout.

Auto Layout

Auto Layout is a powerful way to layout views for iOS development in a future-friendly, device-agnostic way. The best resources to get started learning about it are found here:

• Apple's Adaptive User Interface page

There are four ways to implement auto layout constraints (of class NSLayoutConstraint), and should generally be done in the following order of preference:

1. Interface Builder
2. Anchor-based constraints
3. Visual Format Language
4. Base API

There are three problems that can occur with auto layout, and they are almost always related to contraints:

1. Unsatisfiable constraints (shows as errors in console)
2. Ambiguous layout (can be seen in console by pausing application and entering po [[UIWindow keyWindow] _autolayoutTrace])
3. Undesirable layouts (everything works properly, but is not laid out as you want)