Update podspec

Author: cruisediary

.swift-version

@@ -0,0 +1 @@
+3.0

Pastel.podspec

@@ -9,19 +9,17 @@
 Pod::Spec.new do |s|
   s.name             = 'Pastel'
   s.version          = '0.1.0'
-  s.summary          = 'A short description of Pastel.'
+  s.summary          = 'Instagram like gradient background animation'
 
 # This description is used to generate tags and improve search results.
 #   * Think: What does it do? Why did you write it? What is the focus?
 #   * Try to keep it short, snappy and to the point.
 #   * Write the description between the DESC delimiters below.
 #   * Finally, don't worry about the indent, CocoaPods strips it!
 
-  s.description      = <<-DESC
-TODO: Add long description of the pod here.
-                       DESC
+  s.description      = 'Instagram like infinity gradient background animation'
 
-  s.homepage         = 'https://github.com/cruz/Pastel'
+  s.homepage         = 'https://github.com/cruisediary/Pastel'
   # s.screenshots     = 'www.example.com/screenshots_1', 'www.example.com/screenshots_2'
   s.license          = { :type => 'MIT', :file => 'LICENSE' }
   s.author           = { 'cruz' => 'cruzdiary@gmail.com' }

Pastel/Classes/PastelView.swift

@@ -0,0 +1,105 @@
+//
+//  PastelView.swift
+//  Pastel
+//
+//  Created by Cruz on 05/05/2017.
+//  Copyright © 2017 CocoaPods. All rights reserved.
+//
+
+import UIKit
+
+class PastelView: UIView {
+
+    struct Animation {
+        static let keyPath = "colors"
+        static let key = "ColorChange"
+    }
+    
+    let gradient = CAGradientLayer()
+    var currentGradient: Int = 0
+    open var animationDuration: TimeInterval = 5.0
+    
+    private var colors: [UIColor] = [UIColor(red: 156/255, green: 39/255, blue: 176/255, alpha: 1.0),
+                             UIColor(red: 255/255, green: 64/255, blue: 129/255, alpha: 1.0),
+                             UIColor(red: 123/255, green: 31/255, blue: 162/255, alpha: 1.0),
+                             UIColor(red: 32/255, green: 76/255, blue: 255/255, alpha: 1.0),
+                             UIColor(red: 32/255, green: 158/255, blue: 255/255, alpha: 1.0),
+                             UIColor(red: 90/255, green: 120/255, blue: 127/255, alpha: 1.0),
+                             UIColor(red: 58/255, green: 255/255, blue: 217/255, alpha: 1.0)]
+    /*
+    // Only override draw() if you perform custom drawing.
+    // An empty implementation adversely affects performance during animation.
+    override func draw(_ rect: CGRect) {
+        // Drawing code
+    }
+    */
+    
+    override init(frame: CGRect) {
+        super.init(frame: frame)
+    }
+    
+    required init?(coder aDecoder: NSCoder) {
+        super.init(coder: aDecoder)
+    }
+    
+    override func awakeFromNib() {
+        super.awakeFromNib()
+    }
+    
+    func startAnimation() {
+        gradient.removeAllAnimations()
+        setup()
+        animateGradient()
+    }
+    
+    fileprivate func setup() {
+        gradient.frame = bounds
+        gradient.colors = currentGradientSet()
+        gradient.startPoint = CGPoint(x:0, y:1)
+        gradient.endPoint = CGPoint(x:1, y:0)
+        gradient.drawsAsynchronously = true
+        
+        layer.insertSublayer(gradient, at: 0)
+    }
+
+    fileprivate func currentGradientSet() -> [CGColor] {
+        guard colors.count > 0 else { return [] }
+        return [colors[currentGradient % colors.count].cgColor,
+                colors[(currentGradient + 1) % colors.count].cgColor]
+    }
+    
+    func setColors(colors: [UIColor]) {
+        guard colors.count > 0 else { return }
+        self.colors = colors
+    }
+    
+    func addColor(color: UIColor) {
+        self.colors.append(color)
+    }
+    
+    func animateGradient() {
+        currentGradient += 1
+        let animation = CABasicAnimation(keyPath: Animation.keyPath)
+        animation.duration = animationDuration
+        animation.toValue = currentGradientSet()
+        animation.fillMode = kCAFillModeForwards
+        animation.isRemovedOnCompletion = false
+        animation.delegate = self
+        gradient.add(animation, forKey: Animation.key)
+    }
+    
+    override func removeFromSuperview() {
+        super.removeFromSuperview()
+        gradient.removeAllAnimations()
+        gradient.removeFromSuperlayer()
+    }
+}
+
+extension PastelView: CAAnimationDelegate {
+    func animationDidStop(_ anim: CAAnimation, finished flag: Bool) {
+        if flag {
+            gradient.colors = currentGradientSet()
+            animateGradient()
+        }
+    }
+}