Powerful theme/skin manager for iOS 9+

Screenshot

Running：open SwiftTheme.xcworkspace, run target PlistDemo

Introduction

The Beginning Of The Story

As part of our project requirement, we need to add night mode to our app. It's not as simple as just changing brightness or alpha on the top-level view—in fact, it needs an entirely new interface: different colors, different alpha, different image cuts. More accurately, "night mode" is a theme/skinning feature that can switch between bright theme and dark themes.

So how do we achieve this? Maybe we can set a global variable that represents the currently selected theme, and use different background colors or image cuts based on the variable during the controller's initialization. But then how do we deal with views that have already been initialized? Yes, we could use notifications to change their colors or image cuts, but this leads to controllers unnecessarily full of notification register/unregister, if...else and UI updating code. Worse, if you forget to unregister the notifications, your app may crash.

After some consideration, we put forward higher requirements on the task: create a simple and reusable themes/skinning framework, here as you see.

Goals

Make SwiftTheme a simple, powerful, high-performance, extensible themes/skinning framework. Provide a unified solution for iOS.

Demos

Index Mode

Vary background color of UIView according to the theme setting:

view.theme_backgroundColor = ["#FFF", "#000"]

Vary text color of UILabel and UIButton:

label.theme_textColor = ["#000", "#FFF"]
button.theme_setTitleColor(["#000", "#FFF"], forState: .Normal)

Vary image of UIImageView:

imageView.theme_image = ["day", "night"]

// It's ok by using UIImage instances if you don't want to use image names.
imageView.theme_image = ThemeImagePicker(images: image1, image2)

A miracle happens after you execute the single line of code below!

// these numbers represent the parameters' index. 
// eg. "view.theme_backgroundColor = ["#FFF", "#000"]", index 0 represents "#FFF", index 1 represents "#000"
ThemeManager.setTheme(index: isNight ? 1 : 0)

Get current theme index.

ThemeManager.currentThemeIndex	// Readonly

Index mode is a fast way for the situation: a few themes, but not many, no need to download more new themes.

Notice About Literal:

// Wrong example:
let colors = ["#FFF", "#000"]
view.theme_backgroundColor = colors

// You should write like this:
view.theme_backgroundColor = ["#FFF", "#000"]
// or this:
let colorPickers: ThemeColorPicker = ["#FFF", "#000"]
view.theme_backgroundColor = colorPickers

Because theme_backgroundColor accepts an argument of type ThemeColorPicker，not Array. Nevertheless, "view.theme_backgroundColor = ["#FFF", "#000"]" does the same as initializing an instance of ThemeColorPicker by "Literal" and passing it to the theme_backgroundColor.

Plist/JSON Mode

You may want to make your app download and install an indefinite number of themes. To fulfill this requirement, we provide plist mode. Simply put, you write configuration info such as colors, image cuts and so on, in a plist file. Then, you can use their keys in the logic code. So, the plist file and the resource files are used to constitute a theme package.

Usage demo of plist mode.

view.theme_backgroundColor = "Global.backgroundColor"
imageView.theme_image = "SelectedThemeCell.iconImage"

Similar with the index mode. Only the specific parameters become keys. And as such, we give it the extension ability.

The plist file name is the first paramter of the switching method. In this example, the plist file and other resource files are in the application bundle. It's also ok if they are in sandbox.

ThemeManager.setTheme(plistName: "Red", path: .mainBundle)

plist mode allow you install more themes without modifying logic code. So, you can add the feature that, downloading and installing themes for your app.

the screenshots of the plist and image files we used above:

Objective-C

Fully compatible with Objective-C, usage demo:

lbl.theme_backgroundColor = [ThemeColorPicker pickerWithColors:@[@"#FAF9F9", @"#E2E2E2"]];

Features

[x] Written in Swift
[x] Fully compatible with Objective-C
[x] Based on runtime
[x] Simple integration
[x] Extension property prefix with "theme_*", friendly with IDE auto-completion
[x] Support UIAppearance
[x] Index mode, fast integration
[x] Plist mode, extend infinite themes
[x] Friendly error logs
[x] Strongly typed ThemePicker, detect errors during compilling
[x] Complete demos

Installation

CocoaPods

pod 'SwiftTheme'
use_frameworks!

Carthage

github "wxxsw/SwiftTheme"

Swift Package Manager

Select Xcode -> File -> Swift Packages -> Add Package Dependency...
Enter https://github.com/wxxsw/SwiftTheme.
Click Next, then select the version, complete.

Source files

Copy all the files in "Sources" folder into your project

Documents

Note：① usage of index mode ② usage of plist mode

Basic Usage

Configure Appearance

SwiftTheme provides new properties for views, they all beigin with theme_. Such as theme_backgroundColor corresponds backgroundColor.

①
view.theme_backgroundColor = ThemeColorPicker(colors: "#FFF", "#000")
view.theme_image = ThemeImagePicker(names: "day", "night")
②
view.theme_backgroundColor = ThemeColorPicker(keyPath: "SomeColorKeyPath")
view.theme_image = ThemeImagePicker(keyPath: "SomeImageKeyPath")

Different type of properties receive different type of Pickers. Thus, IDE will warn you if you pass a wrong parameter.

Switch Themes

When you switch themes, all the theme_ properties you set will update with animation. Usage:

①
ThemeManager.setTheme(index: 0) // ThemePickers will use the first parameter, eg. "#FFF" "day"
ThemeManager.setTheme(index: 1) // ThemePickers will use the second parameter, eg. "#000" "night"
②
// use "day.plist" in the appllication bundle as the theme configuration file. 
// In this mode, SwiftTheme will find the resource files in the appllication bundle.
ThemeManager.setTheme(plistName: "day", path: .mainBundle)
// use "night.plist" in the sandbox as the theme configuration file, "someURL" is its file path. 
// In this mode, SwiftTheme will find the resource files in the same path.
ThemeManager.setTheme(plistName: "night", path: .sandbox(someURL))
// use a dictionary as the theme configuration, but find resource files in the sandbox.(Not recommend)
ThemeManager.setTheme(dict: dict, path: .sandbox(someURL))

Custom Behaviors

SwiftTheme posts a notification named ThemeUpdateNotification when theme changes, you can observe this notification anywhere and do whatever you want:

NotificationCenter.default.addObserver(
	self, 
	selector: #selector(doSomethingMethod),
	name: NSNotification.Name(rawValue: ThemeUpdateNotification), 
	object: nil
)

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(doSomethingMethod) name:@"ThemeUpdateNotification" object:nil];

Now Supported Properties

Child classes inherit the properties from their super class, such as UILabel have theme_alpha inherited from UIView. These properties will not be list in child classes below.

UIView

var theme_alpha: ThemeCGFloatPicker?
var theme_backgroundColor: ThemeColorPicker?
var theme_tintColor: ThemeColorPicker?

UIApplication

func theme_setStatusBarStyle(picker: ThemeStatusBarStylePicker, animated: Bool)

UIBarButtonItem

var theme_tintColor: ThemeColorPicker?

UILabel

var theme_font: ThemeFontPicker?
var theme_textColor: ThemeColorPicker?
var theme_textAttributes: ThemeStringAttributesPicker?
var theme_highlightedTextColor: ThemeColorPicker?
var theme_shadowColor: ThemeColorPicker?

UINavigationBar

var theme_barStyle: ThemeBarStylePicker?
var theme_barTintColor: ThemeColorPicker?
var theme_titleTextAttributes: ThemeDictionaryPicker?

UITabBar

var theme_barStyle: ThemeBarStylePicker?
var theme_barTintColor: ThemeColorPicker?

UITableView

var theme_separatorColor: ThemeColorPicker?

UITextField

var theme_font: ThemeFontPicker?
var theme_keyboardAppearance: ThemeKeyboardAppearancePicker?
var theme_textColor: ThemeColorPicker?
var theme_placeholderAttributes: ThemeDictionaryPicker?

UITextView

var theme_font: ThemeFontPicker?
var theme_textColor: ThemeColorPicker?

UIToolbar

var theme_barStyle: ThemeBarStylePicker?
var theme_barTintColor: ThemeColorPicker?

UISegmentedControl

var theme_selectedSegmentTintColor: ThemeColorPicker?
func theme_setTitleTextAttributes(_ picker: ThemeStringAttributesPicker?, forState state: UIControl.State)

UISwitch

var theme_onTintColor: ThemeColorPicker?
var theme_thumbTintColor: ThemeColorPicker?

UISlider

var theme_thumbTintColor: ThemeColorPicker?
var theme_minimumTrackTintColor: ThemeColorPicker?
var theme_maximumTrackTintColor: ThemeColorPicker?

UISearchBar

var theme_barStyle: ThemeBarStylePicker?
var theme_barTintColor: ThemeColorPicker?

UIProgressView

var theme_progressTintColor: ThemeColorPicker?
var theme_trackTintColor: ThemeColorPicker?

UIPageControl

var theme_pageIndicatorTintColor: ThemeColorPicker?
var theme_currentPageIndicatorTintColor: ThemeColorPicker?

UIImageView

var theme_image: ThemeImagePicker?

UIActivityIndicatorView

var theme_activityIndicatorViewStyle: ThemeActivityIndicatorViewStylePicker?

UIButton

func theme_setImage(picker: ThemeImagePicker?, forState state: UIControlState)
func theme_setBackgroundImage(picker: ThemeImagePicker?, forState state: UIControlState)
func theme_setTitleColor(picker: ThemeColorPicker?, forState state: UIControlState)
func theme_setAttributedTitle(picker: ThemeAttributedStringPicker?, forState state: UIControlState)

CALayer

var theme_backgroundColor: ThemeCGColorPicker?
var theme_borderWidth: ThemeCGFloatPicker?
var theme_borderColor: ThemeCGColorPicker?
var theme_shadowColor: ThemeCGColorPicker?

CATextLayer

var theme_foregroundColor: ThemeCGColorPicker?

CAGradientLayer

var theme_colors: ThemeAnyPicker?

UIRefreshControl

var theme_titleAttributes: ThemeDictionaryPicker?

UIVisualEffectView

var theme_effect: ThemeVisualEffectPicker?

Picker

ThemeColorPicker

// supported formats:
// "#ffcc00"		RGB
// "#ffcc00dd"		RGBA
// "#FFF"			RGB in short
// "#013E"			RGBA in short
①
ThemeColorPicker(colors: "#FFFFFF", "#000")
ThemeColorPicker(colors: UIColor.red, UIColor.blue)
ThemeColorPicker.pickerWithColors(["#FFFFFF", "#000"])
ThemeColorPicker.pickerWithUIColors([UIColor.red, UIColor.blue])
②
ThemeColorPicker(keyPath: "someStringKeyPath")
ThemeColorPicker.pickerWithKeyPath("someStringKeyPath")

ThemeImagePicker

①
ThemeImagePicker(names: "image1", "image2")
ThemeImagePicker.pickerWithNames(["image1", "image2"])
ThemeImagePicker(images: UIImage(named: "image1")!, UIImage(named: "image2")!)
ThemeImagePicker.pickerWithImages([UIImage(named: "image1")!, UIImage(named: "image2")!])
②
ThemeImagePicker(keyPath: "someStringKeyPath")
ThemeImagePicker.pickerWithKeyPath("someStringKeyPath")

ThemeCGFloatPicker

①
ThemeCGFloatPicker(floats: 1.0, 0.7)
ThemeCGFloatPicker.pickerWithFloats([1.0, 0.7])
②
ThemeCGFloatPicker(keyPath: "someNumberKeyPath")
ThemeCGFloatPicker.pickerWithKeyPath("someNumberKeyPath")

ThemeCGColorPicker

①
ThemeCGColorPicker(colors: "#FFFFFF", "#000")
ThemeCGColorPicker(colors: UIColor.red, UIColor.blue)
ThemeCGColorPicker(colors: UIColor.red.cgColor, UIColor.blue.cgColor)
ThemeCGColorPicker.pickerWithColors(["#FFFFFF", "#000"])
ThemeCGColorPicker.pickerWithUIColors([UIColor.blue, UIColor.red])
②
ThemeCGColorPicker(keyPath: "someStringKeyPath")
ThemeCGColorPicker.pickerWithKeyPath("someStringKeyPath")

ThemeFontPicker

①
ThemeFontPicker(fonts: UIFont.systemFont(ofSize: 10), UIFont.systemFont(ofSize: 11))
ThemeFontPicker.pickerWithFonts([UIFont.systemFont(ofSize: 10), UIFont.systemFont(ofSize: 11)])
②
// name the key you like, but the available values format like this: "PingFangSC-Regular,16"
ThemeFontPicker(keyPath: "someStringKeyPath")
ThemeFontPicker.pickerWithKeyPath("someStringKeyPath")

ThemeDictionaryPicker

①
ThemeDictionaryPicker(dicts: ["key": "value"], ["key": "value"])
ThemeDictionaryPicker.pickerWithDicts([["key": "value"], ["key": "value"]])
②
ThemeDictionaryPicker(keyPath: "someStringKeyPath") { (Any?) -> [String: AnyObject]? in ... }

ThemeStringAttributesPicker

①
ThemeStringAttributesPicker(["key": "value"], ["key": "value"])
ThemeStringAttributesPicker.pickerWithAttributes([NSAttributedStringKey.font: UIFont.systemFont(ofSize: 16)])
②
ThemeStringAttributesPicker(keyPath: "someStringKeyPath") { (Any?) -> [NSAttributedString.Key: Any]? in ... }

ThemeAttributedStringPicker

①
ThemeAttributedStringPicker(NSAttributedString(...), NSAttributedString(...))
ThemeAttributedStringPicker.pickerWithAttributedStrings([NSAttributedString(...)])
②
ThemeAttributedStringPicker(keyPath: "someStringKeyPath") { (Any?) -> NSAttributedString? in ... }

ThemeBarStylePicker

①
ThemeBarStylePicker(styles: .default, .black)
ThemeBarStylePicker.pickerWithStyles([.default, .black])
ThemeBarStylePicker.pickerWithStringStyles(["default", "black"])
②
// name the key you like, but the available values are "default" and "black"
ThemeBarStylePicker(keyPath: "someStringKeyPath")
ThemeBarStylePicker.pickerWithKeyPath("someStringKeyPath")

ThemeStatusBarStylePicker

①
ThemeStatusBarStylePicker(styles: .default, .lightContent, .darkContent)
ThemeStatusBarStylePicker.pickerWithStyles([.default, .lightContent, .darkContent])
ThemeStatusBarStylePicker.pickerWithStringStyles(["default", "lightContent", "darkContent"])
②
// name the key you like, but the available values are "default", "lightContent" and "darkContent"
ThemeStatusBarStylePicker(keyPath: "someStringKeyPath")
ThemeStatusBarStylePicker.pickerWithKeyPath("someStringKeyPath")

ThemeKeyboardAppearancePicker

①
ThemeKeyboardAppearancePicker(styles: .default, .dark, .light)
ThemeKeyboardAppearancePicker.pickerWithStyles([.default, .dark, .light])
ThemeKeyboardAppearancePicker.pickerWithStringStyles(["default", "dark", "light"])
②
// name the key you like, but the available values are "default", "dark" and "light"
ThemeKeyboardAppearancePicker(keyPath: "someStringKeyPath")
ThemeKeyboardAppearancePicker.pickerWithKeyPath("someStringKeyPath")

ThemeActivityIndicatorViewStylePicker

①
ThemeActivityIndicatorViewStylePicker(styles: .whiteLarge, .white, .gray)
ThemeActivityIndicatorViewStylePicker.pickerWithStyles([.whiteLarge, .white, .gray])
ThemeActivityIndicatorViewStylePicker.pickerWithStringStyles(["whiteLarge", "white", "gray"])
②
// name the key you like, but the available values are "whiteLarge", "white" and "gray"
ThemeActivityIndicatorViewStylePicker(keyPath: "someStringKeyPath")
ThemeActivityIndicatorViewStylePicker.pickerWithKeyPath("someStringKeyPath")

ThemeVisualEffectPicker

①
ThemeVisualEffectPicker(effects: UIBlurEffect(style: .light), UIBlurEffect(style: .dark))
ThemeVisualEffectPicker.pickerWithEffects([UIBlurEffect(style: .light), UIBlurEffect(style: .dark)])
ThemeVisualEffectPicker.pickerWithStringEffects(["light", "dark", "extralight", "prominent", "regular"])
②
// name the key you like, but the available values are "light", "dark", "extralight", "prominent" and "regular"
ThemeVisualEffectPicker(keyPath: "someStringKeyPath")
ThemeVisualEffectPicker.pickerWithKeyPath("someStringKeyPath")

ThemeAnyPicker

①
ThemeAnyPicker(anys: 0, "123", UIColor.red)
ThemeAnyPicker.pickerWithAnys([0, "123", UIColor.red])
②
ThemeAnyPicker(keyPath: "someStringKeyPath")
ThemeAnyPicker.pickerWithKeyPath("someStringKeyPath")

Download this project and find more. There are four demo targets:

Demo shows how to use index mode and how to save the last selection of themes and other general usages.
PlistDemo shows how to use plist mode and how to download themes that packaged in zip files.
JsonDemo is like PlistDemo, but use json.
OCDemo is Demo's Objective-C version.
TVOSDemo is used to test tvos compatibility.

FAQ

Why doesn't theme_setStatusBarStyle work as expected?

In your app's Info.plist you will need to set View Controller-based status bar appearence to NO.
Can I manually cancel the theme of a property?

Sure, just make it nil—example: view.theme_backgroundColor = nil.

Contribution

Issue

If you find a bug or need a help, you can create a issue

Pull Request

We are happy to accept pull requests :D. But please make sure it's needed by most developers and make it simple to use. If you are not sure, create an issue and we can discuss it before you get to coding.

Contributors

Gesen, Zhoujun, Kevin Cramer

Lisence

The MIT License (MIT)

GitHub

https://github.com/wxxsw/SwiftTheme