JXTheme is a lightweight library for theme properties configuration.

Feature

Support for iOS 9+, let your app implement DarkMode earlier;
Use the theme namespace attribute: view.theme.xx = xx. Say goodbye to the theme_xx attribute extension usage;
ThemeStyle can be customized by extension, no longer limited to light and dark;
provides the customization attribute as a callback entry for theme switching, with the flexibility to configure any property. It is no longer limited to the provided attributes such as backgroundColor and textColor;
supports the control setting overrideThemeStyle, which affects its child views;

Preview

Requirements

iOS 9.0+
XCode 10.2.1+
Swift 5.0+

Install

Manual

Clone code, drag the Sources folder into the project, you can use it;

CocoaPods

Target '<Your Target Name>' do
     Pod 'JXTheme'
End

Execute pod repo update first, then execute pod install

Carthage

Add in the cartfile:

Github "pujiaxin33/JXTheme"

Then execute carthage update --platform iOS. For other configurations, please refer to the Carthage documentation.

#Usage

Add a custom style by extension`ThemeStyle`

ThemeStyle only provides a default unspecified style. Other business styles need to be added by themselves. For example, only light and dark are supported. The code is as follows:

Extension ThemeStyle {
    Static let light = ThemeStyle(rawValue: "light")
    Static let dark = ThemeStyle(rawValue: "dark")
}

Basic use

view.theme.backgroundColor = ThemeProvider({ (style) in
    If style == .dark {
        Return .white
    }else {
        Return .black
    }
})
imageView.theme.image = ThemeProvider({ (style) in
    If style == .dark {
        Return UIImage(named: "catWhite")!
    }else {
        Return UIImage(named: "catBlack")!
    }
})

Custom Properties Configuration

If the library does not natively support a certain attribute, it can be handled uniformly in the customization.

View.theme.customization = ThemeProvider({[weak self] style in
    / / You can choose any other property
    If style == .dark {
        Self?.view.bounds = CGRect(x: 0, y: 0, width: 30, height: 30)
    }else {
        Self?.view.bounds = CGRect(x: 0, y: 0, width: 80, height: 80)
    }
})

extension ThemeWrapper add property

If a certain attribute is frequently used in the project, and it is troublesome to use the above Custom Properties Configuration, you can add the desired property by yourself with the extension ThemeWrapper. (Ps: You can also submit a Pull Request to add)

The following is an example of UILabel adding shadowColor:

//Custom add ThemeProperty, currently only supports UIView, CALayer, UIBarItem and their subclasses
extension ThemeWrapper where Base: UILabel {
    var shadowColor: ThemeProvider<UIColor>? {
        set(new) {
            let baseItem = self.base
            ThemeTool.setupViewThemeProperty(view: self.base, key: "UILabel.shadowColor", provider: new) {[weak baseItem] (style) in
                baseItem?.shadowColor = new?.provider(style)
            }
        }
        get {return ThemeTool.getThemeProvider(target: self.base, with: "UILabel.shadowColor") as? ThemeProvider<UIColor>}
    }
}

The call is still the same:

//Custom attribute shadowColor
shadowColorLabel.shadowOffset = CGSize(width: 0, height: 2)
shadowColorLabel.theme.shadowColor = ThemeProvider({ style in
    if style == .dark {
        return .red
    }else {
        return .green
    }
})

Configuring the package example

JXTheme is a lightweight base library that provides configuration of theme properties, and does not restrict which way to load resources. The three examples provided below are for reference only.

ThemeProvider custom initializer

For example, add the following code to the project:

extension ThemeProvider {
     //Adjust according to the ThemeStyle supported by the project
     init(light: T, dark: T) {
         self.init {style in
             switch style {
             case .light: return light
             case .dark: return dark
             default: return light
             }
         }
     }
}

Call in business code:

tableView.theme.backgroundColor = ThemeProvider(light: UIColor.white, dark: UIColor.white)

In this way, the form of ThemeProvider closure can be avoided and it is more concise.

General Configuration Package Example

There is a UI standard for general skinning needs. For example, UILabel.textColor defines three levels, the code is as follows:

Enum TextColorLevel: String {
    Case normal
    Case mainTitle
    Case subTitle
}

Then you can encapsulate a global function and pass TextColorLevel to return the corresponding configuration closure, which can greatly reduce the amount of code during configuration. The global functions are as follows:

Func dynamicTextColor(_ level: TextColorLevel) -> ThemeProvider<UIColor> {
    Switch level {
    Case .normal:
        Return ThemeProvider({ (style) in
            If style == .dark {
                Return UIColor.white
            }else {
                Return UIColor.gray
            }
        })
    Case .mainTitle:
        ...
    Case .subTitle:
        ...
    }
}

The code for configuring the theme properties is as follows:

themeLabel.theme.textColor = dynamicTextColor(.mainTitle)

Local Plist file configuration example

Same as General Configuration Package, except that the method loads the configuration value from the local Plist file. The specific code participates in the Example``StaticSourceManager class.

Add topics based on server dynamics

Same as General Configuration Package, except that the method loads the specific values of the configuration from the server. The specific code participates in the DynamicSourceManager class of Example.

Stateful controls

Some business requirements exist for a control with multiple states, such as checked and unchecked. Different states have different configurations for different theme. The configuration code is as follows:

statusLabel.theme.textColor = ThemeProvider({[weak self] (style) in
    If self?.statusLabelStatus == .isSelected {
        / / selected state a configuration
        If style == .dark {
            Return .red
        }else {
            Return .green
        }
    }else {
        //Unselected another configuration
        If style == .dark {
            Return .white
        }else {
            Return .black
        }
    }
})

When the state of the control is updated, you need to refresh the current theme property configuration, the code is as follows:

Func statusDidChange() {
    statusLabel.theme.textColor?.refresh()
}

If your control supports multiple state properties, such as textColor, backgroundColor, font, etc., you can call the refresh method without using one of the theme properties. You can use the following code to complete all the configured themes. Property refresh:

Func statusDidChange() {
    statusLabel.theme.refresh()
}

overrideThemeStyle

Regardless of how the theme switches, overrideThemeStyleParentView and its subview's themeStyle are dark

overrideThemeStyleParentView.theme.overrideThemeStyle = .dark

Principle

Principle

Other tips

Why use the `theme` namespace attribute instead of the `theme_xx` extension attribute?

If you extend N functions to the system class, when you use the class, there are N extended methods that interfere with your choice. Especially if you are doing other business development, not when you want to configure theme properties.
Well-known three-party libraries like Kingfisher, SnapKit, etc., all use namespace attributes to implement extensions to system classes. This is a more Swift way of writing and worth learning.

Theme Switch Notification

Extension Notification.Name {
    Public static let JXThemeDidChange = Notification.Name("com.jiaxin.theme.themeDidChangeNotification")
}

`ThemeManager` stores the theme configuration according to the user ID

/// Configure the stored flag key. Can be set to the user's ID, so that in the same phone, you can record the configuration of different users. You need to set this property first and then set other values.
Public var storeConfigsIdentifierKey: String = "default"

Migrating to System API Guide

When your app supports iOS13 at the minimum, you can migrate to the system plan if you need to follow the guidelines below. [Migrate to System API Guide, click to read] (https://github.com/pujiaxin33/JXTheme/blob/master/Document/%E8%BF%81%E7%A7%BB%E5%88%B0%E7% B3%BB%E7%BB%9FAPI%E6%8C%87%E5%8D%97.md)

Currently supported classes and their properties

The properties here are inherited. For example, UIView supports the backgroundColor property, then its subclass UILabel also supports backgroundColor. If you don't have the class or property you want to support, you are welcome to extend the PullRequest.

UIView

backgroundColor
tintColor
alpha
customization

UILabel

font
textColor
shadowColor
highlightedTextColor
attributedText

UIButton

func setTitleColor(_ colorProvider: ThemeColorDynamicProvider?, for state: UIControl.State)
func setTitleShadowColor(_ colorProvider: ThemeColorDynamicProvider?, for state: UIControl.State)
func setAttributedTitle(_ textProvider: ThemeAttributedTextDynamicProvider?, for state: UIControl.State)
func setImage(_ imageProvider: ThemeImageDynamicProvider?, for state: UIControl.State)
func setBackgroundImage(_ imageProvider: ThemeImageDynamicProvider?, for state: UIControl.State)

UITextField

font
textColor
attributedText
attributedPlaceholder
keyboardAppearance

UITextView

font
textColor
attributedText
keyboardAppearance

UIImageView

image

CALayer

backgroundColor
borderColor
borderWidth
shadowColor
customization

CAShapeLayer

fillColor
strokeColor

UINavigationBar

barStyle
barTintColor
titleTextAttributes
largeTitleTextAttributes

UITabBar

barStyle
barTintColor
shadowImage

UISearchBar

barStyle
barTintColor
keyboardAppearance

UIToolbar

barStyle
barTintColor

UISwitch

onTintColor
thumbTintColor

UISlider

thumbTintColor
minimumTrackTintColor
maximumTrackTintColor
minimumValueImage
maximumValueImage

UIRefreshControl

attributedTitle

UIProgressView

progressTintColor
trackTintColor
progressImage
trackImage

UIPageControl

pageIndicatorTintColor
currentPageIndicatorTintColor

UIBarItem

func setTitleTextAttributes(_ attributesProvider: ThemeAttributesDynamicProvider?, for state: UIControl.State)
image

UIBarButtonItem

tintColor

UIActivityIndicatorView

style
color

UIScrollView

indicatorStyle

UITableView

separatorColor
sectionIndexColor
sectionIndexBackgroundColor

Contribution

If you have any questions or suggestions, please feel free to contact us by Issue and Pull Request🤝