[Swift] Apply a gradation filter

In 3 lines

--Create a class for gradation --Load class for gradient --Pass the value to the class for gradient

Create a color setting class

This time I will make another class. If you want to change the color depending on the page, this one is more effective for crushing, and ** readability ** is also improved (not scolded by the reviewer).

ChangeColor.swift

import Foundation
import UIKit

class ChangeColor {
  func changeColor(topR:CGFloat, topG:CGFloat, topB:CGFloat,
                   topAlpha:CGFloat,
                   bottomR:CGFloat, bottomG:CGFloat, bottomB:CGFloat,
                   bottomAlpha:CGFloat)
  ->CAGradientLayer {
  
    //Gradient start color
    let topColor = UIColor(red: topR, green: topG, blue: topB, alpha: topAlpha)
    
    //Gradient end color
    let bottomColor = UIColor(red: bottomR, green: bottomG, blue: bottomB, alpha: bottomAlpha)
    
    //Manage gradation colors in an array
    let gradientColor = [topColor.cgColor, bottomColor.cgColor]
    let gradientLayer = CAGradientLayer()
    gradientLayer.colors = gradientColor
    
    return gradientLayer
  }
}

Pass a value to the color settings class

ViewController.swift

class ViewController: UIViewController {

  //Instantiate a color setting class
  var changeColor = ChangeColor()
  var gradientLayer = CAGradientLayer()
  
  override func viewDidLoad() {
    super.viewDidLoad()
     
    //Pass a value to the color settings class
    gradientLayer = changeColor.changeColor(topR: 0.07, topG: 0.13, topB: 0.26, topAlpha: 1.0, bottomR: 0.54, bottomG: 0.74, bottomB: 0.74, bottomAlpha: 1.0)
    //bounds represent the whole
    gradientLayer.frame = view.bounds
    
    view.layer.insertSublayer(gradientLayer, at: 0)
  }
}

By the way, what is "instantiating"? I am using it vaguely.