[Theme Manager] #theme #swift3 #apperance

ThemeManager.swift

import UIKit

enum Theme: Int {
  
  case dark, light
  
  var dark: UIColor {
    switch self {
    case .dark:
      return UIColor().colorFromHexString("212121")
    case .light:
      return UIColor().colorFromHexString("E0E0E0")
    }
  }
  
  var background: UIColor {
    switch self {
    case .dark:
      return UIColor().colorFromHexString("303030")
    case .light:
      return UIColor().colorFromHexString("EEEEEE")
    }
  }
  
  var light: UIColor {
    switch self {
    case .dark:
      return UIColor().colorFromHexString("424242")
    case .light:
      return UIColor().colorFromHexString("FFFFFF")
    }
  }
  
  //Customizing the Navigation Bar
  var barStyle: UIBarStyle {
    switch self {
    case .dark:
      return .default
    case .light:
      return .black
    }
  }
  
  var navigationBackgroundImage: UIImage? {
    return self == .dark ? UIImage(named: "navBackground") : nil
  }
  
  var tabBarBackgroundImage: UIImage? {
    return self == .dark ? UIImage(named: "tabBarBackground") : nil
  }
  
  var mainColor: UIColor {
    switch self {
    case .dark:
      return UIColor().colorFromHexString("ffffff")
    case .light:
      return UIColor().colorFromHexString("000000")
    }
  }
  
  var backgroundColor: UIColor {
    switch self {
    case .dark:
      return UIColor().colorFromHexString("ffffff")
    case .light:
      return UIColor().colorFromHexString("000000")
    }
  }
  
  var secondaryColor: UIColor {
    switch self {
    case .dark:
      return UIColor().colorFromHexString("ffffff")
    case .light:
      return UIColor().colorFromHexString("000000")
    }
  }
  
  var titleTextColor: UIColor {
    switch self {
    case .dark:
      return UIColor().colorFromHexString("ffffff")
    case .light:
      return UIColor().colorFromHexString("000000")
    }
  }
  var subtitleTextColor: UIColor {
    switch self {
    case .dark:
      return UIColor().colorFromHexString("ffffff")
    case .light:
      return UIColor().colorFromHexString("000000")
    }
  }
}


class ThemeManager {
  
  // ThemeManager
  static func currentTheme() -> Theme {
    if let storedTheme = (UserDefaults.standard.value(forKey: Keys.selectedTheme) as AnyObject).integerValue {
      return Theme(rawValue: storedTheme)!
    } else {
      return .light
    }
  }
  
  static func applyTheme(theme: Theme) {
    UserDefaults.standard.setValue(theme.rawValue, forKey: Keys.selectedTheme)
    UserDefaults.standard.synchronize()
    
    let sharedApplication = UIApplication.shared
    sharedApplication.delegate?.window??.tintColor = theme.mainColor
    
    UINavigationBar.appearance().barStyle = theme.barStyle
    UINavigationBar.appearance().setBackgroundImage(theme.navigationBackgroundImage, for: .default)
    
    UITabBar.appearance().barStyle = theme.barStyle
    UITabBar.appearance().backgroundImage = theme.tabBarBackgroundImage
    
    let tabIndicator = UIImage(named: "tabBarSelectionIndicator")?.withRenderingMode(.alwaysTemplate)
    let tabResizableIndicator = tabIndicator?.resizableImage(withCapInsets: UIEdgeInsets(top: 0, left: 2.0, bottom: 0, right: 2.0))
    UITabBar.appearance().selectionIndicatorImage = tabResizableIndicator
    
    let controlBackground = UIImage(named: "controlBackground")?.withRenderingMode(.alwaysTemplate)
      .resizableImage(withCapInsets: UIEdgeInsets(top: 3, left: 3, bottom: 3, right: 3))
    let controlSelectedBackground = UIImage(named: "controlSelectedBackground")?
      .withRenderingMode(.alwaysTemplate)
      .resizableImage(withCapInsets: UIEdgeInsets(top: 3, left: 3, bottom: 3, right: 3))
    
    UISegmentedControl.appearance().setBackgroundImage(controlBackground, for: .normal, barMetrics: .default)
    UISegmentedControl.appearance().setBackgroundImage(controlSelectedBackground, for: .selected, barMetrics: .default)
    
    UIStepper.appearance().setBackgroundImage(controlBackground, for: .normal)
    UIStepper.appearance().setBackgroundImage(controlBackground, for: .disabled)
    UIStepper.appearance().setBackgroundImage(controlBackground, for: .highlighted)
    UIStepper.appearance().setDecrementImage(UIImage(named: "fewerPaws"), for: .normal)
    UIStepper.appearance().setIncrementImage(UIImage(named: "morePaws"), for: .normal)
    
    UISlider.appearance().setThumbImage(UIImage(named: "sliderThumb"), for: .normal)
    UISlider.appearance().setMaximumTrackImage(UIImage(named: "maximumTrack")?
      .resizableImage(withCapInsets: UIEdgeInsets(top: 0, left: 0.0, bottom: 0, right: 6.0)), for: .normal)
    UISlider.appearance().setMinimumTrackImage(UIImage(named: "minimumTrack")?
      .withRenderingMode(.alwaysTemplate)
      .resizableImage(withCapInsets: UIEdgeInsets(top: 0, left: 6.0, bottom: 0, right: 0)), for: .normal)
    
    UISwitch.appearance().onTintColor = theme.mainColor.withAlphaComponent(0.3)
    UISwitch.appearance().thumbTintColor = theme.mainColor
  }
}