Conveniences for programmatically generating image assets and styling UIButton

by iOS Example

roundrect

Conveniences for programmatically generating image assets and styling UIButton.

Creating Images

The conveniences in ImageGeneration.swift allow images to be generated from a view, or given various style properties like fill, stroke, corner radius, etc. For example, to create a 3px/3px image with a 1px blue stroke and a single red fill:

let image = UIImage(
  fill: .red,
  stroke: (
    color: .blue, 
    width: 1
  )
)

This image can be made resizable and applied to a UIButton, but since there is a lot of busywork associated with handling all the different states a button can have, the conveniences in ButtonStyle can be used instead. A combination of a button Style (eg. filled vs bordered) and Theme (eg. light or dark) can be provided when creating or modifying an existing UIButton:

let button = UIButton(
  style: .filled(
    cornerRadius: 8
  ),
  theme: .light
)

This will yield a button with a tintable fill and a corner radius of 8.

Code coverage

Image generation and button styling tests rely on FBSnapshotTestCase, which is linked using Carthage. To see what's tested, view the reference images in roundrectTests/recorded/. SampleSheetTests generates an asset displaying every combination of style and theme, providing a quick preview of what's available:

GitHub