SuitUp

Introduction

Easy to use and lightweight theme manager for iOS applications written in Swift with UIKit, but taking advantages of Objective-C reflection capabilities.

Repository also contains an Example app, which helps you to define themes and styles in a protocol oriented way.

Example

Just open SuitUp workspace and have fun!

Installation

Use CocoaPods:

pod 'SuitUp'

or you can install manually:

Download it, then drag and drop the contents of SuitUp/SuitUp folder into your project.

Import

Of course don't miss to import SuitUp where you want to use.

import SuitUp

Themes

A theme contains color, font and image definitions based on the design, but you can extend it with anything you need. In SuitUp you can change between these themes, like the usual light and dark modes.

Colors, fonts and images

The base theme contains these types of attributes, but you can extend it if you derive a protocol and use this extended one everywhere in your project. In the example project you can see a color palette like the following:

protocol ColorPalette: Colors {
    var primary: UIColor { get }
    var secondary: UIColor { get }
    var tertiary: UIColor { get }
    
    var primaryText: UIColor { get }
    var secondaryText: UIColor { get }
}

Registration

After you successfully created your themes, you have to register them during application launch inside didFinishLaunchingWithOptions: in AppDelegate.

SuitUp.shared.registerThemes(SunriseTheme(), SunsetTheme())
SuitUp.shared.logLevel = .warning

and you can set the log level to warning or info based on your preferences. My suggestion is info level in the beginning, because you will see more information about style settings under the hood if you choose this level.

Theme change

You can change currently used theme in runtime with changeTheme(to:) function in SuitUp.

Style

Each style contains stylable properties mirrored from the UI component, that you want to style. However styles live completely independent from UI components, so you never have to extend your UI components with any SuitUp related code snippets. You can define these properties in a descriptor, which you can read about in the next section. So if UIView has a backgroundColor property and you want to style it through SuitUp, you have to add this property to the style. It works with any property, but only if the property is accessible from Objective-C code. You can achieve this if you use @objc annotation before the property. (or @objcMembers on the class) Each style have to subclass NSObject.

Style descriptor

It contains stylable property definitions. Important note that you have to use the exactly same name in descriptors, what you use in the UI component. So if you have a backgroundColor property in UIView, you have to define by the same name in the descriptor and you have to use @objc annotation before protocol, like the following:

@objc
protocol ViewStyleDescriptor: StyleDescriptor {
    var backgroundColor: UIColor { get }
}

How to use items from themes

There is an extension on StyleDescriptor protocol in the Example project, so you can follow this pattern:

extension StyleDescriptor {
    var colors: ColorPalette { SuitUp.shared.currentTheme?.colors as! ColorPalette }
    var fonts: FontPalette { SuitUp.shared.currentTheme?.fonts as! FontPalette }
    var images: ImagePalette { SuitUp.shared.currentTheme?.images as! ImagePalette }
}

or use the very long form whenever needed:

(SuitUp.shared.currentTheme?.colors as? ColorPalette).primary

Usage

You can set style by a style instance given to the apply(style:) function. It is available through a UIView extension.

primaryView.apply(style: PrimaryViewStyle())