[UITabBarControllerExtension] #swift3 #tabbar

UIImageExtension.swift

import UIKit

extension UIImage {
  class func imageWithColor(color: UIColor, size: CGSize) -> UIImage {
    let rect: CGRect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
    UIGraphicsBeginImageContextWithOptions(size, false, 0)
    color.setFill()
    UIRectFill(rect)
    let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()
    return image
  }
  
  func with(color: UIColor) -> UIImage {
    guard let cgImage = self.cgImage else {
      return self
    }
    UIGraphicsBeginImageContextWithOptions(size, false, scale)
    let context = UIGraphicsGetCurrentContext()!
    context.translateBy(x: 0, y: size.height)
    context.scaleBy(x: 1.0, y: -1.0)
    context.setBlendMode(.normal)
    let imageRect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
    context.clip(to: imageRect, mask: cgImage)
    color.setFill()
    context.fill(imageRect)
    let newImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext();
    return newImage
  }
}

UITabBarControllerExtension.swift

import UIKit

extension UITabBarController {
  func removeTabbarItemsText() {
    tabBar.items?.forEach {
      $0.title = ""
      $0.imageInsets = UIEdgeInsets(top: 6, left: 0, bottom: -6, right: 0)
    }
  }
  
  func changeUnselectedItemColor(to unselectedColor: UIColor) {
    tabBar.items?.forEach {
      $0.image = $0.selectedImage!.with(color: unselectedColor).withRenderingMode(.alwaysOriginal)
      UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName : unselectedColor], for: .normal)
    }
  }
  
  func changeSelectedItemColor(to selectedColor: UIColor) {
    tabBar.tintColor = selectedColor
    UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName : selectedColor], for: .selected)
  }
  
  func changeSelectedItemBackgroundColor(to backgroundColor: UIColor) {
    let numberOfItems = CGFloat(tabBar.items!.count)
    
    let tabBarItemSize = CGSize(width: tabBar.frame.width / numberOfItems,
                                height: tabBar.frame.height)
    
    tabBar.selectionIndicatorImage = UIImage.imageWithColor(color: backgroundColor, size: tabBarItemSize).resizableImage(withCapInsets: .zero)
    
    tabBar.frame.size.width = self.view.frame.width + 4
    tabBar.frame.origin.x = -2
  }
}