iOS Accessibility Model

Abstract

Before we dig into the accessibility features available, it’s useful to know a little about how Apple’s accessibility features work on a low level. We’re all familiar with the visual user interface presented by our app. It’s what you see and interact with on our device’s screen. Our visual user interface is made up of the controls, text, and images we add in code or through Interface Builder. These are pulled together with stacks or constraints and finished with some appropriate color. But your app has a second user interface, the Accessibility User Interface, or accessibility tree.