♻️ :: Moved logic from view to view-model

Example/Pods/Pods.xcodeproj/project.pbxproj

@@ -38,6 +38,7 @@
 		4B5A5EBA97A912894C10D040B5A1225D /* Pods-GradientLoadingBar_Tests-umbrella.h in Headers */ = {isa = PBXBuildFile; fileRef = B8B5E60915249521CF9DC7208F2D5774 /* Pods-GradientLoadingBar_Tests-umbrella.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		604C51928D4CFDAE15A6CAB6327B68D6 /* Foundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = B802EDB707F8CE8EBD66EB815051159F /* Foundation.framework */; };
 		640E8ABC2313DD280008C5A6 /* Constants.swift in Sources */ = {isa = PBXBuildFile; fileRef = 640E8ABB2313DD280008C5A6 /* Constants.swift */; };
+		640E8ABE2313E4540008C5A6 /* GradientActivityIndicatorViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 640E8ABD2313E4540008C5A6 /* GradientActivityIndicatorViewModel.swift */; };
 		681130A53798D8143A2C972C3351D165 /* Foundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = B802EDB707F8CE8EBD66EB815051159F /* Foundation.framework */; };
 		757352462D522BDB0B228DE9880106ED /* Pods-GradientLoadingBar_Tests-dummy.m in Sources */ = {isa = PBXBuildFile; fileRef = 4E014E4CD6DE59FD4C7C3D12C2BC9474 /* Pods-GradientLoadingBar_Tests-dummy.m */; };
 		7D00DA81B76090CC52ADBEC7E56F8A4B /* GradientLoadingBarController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 24D0266A0CC59CB31FD536223C0F4096 /* GradientLoadingBarController.swift */; };
@@ -125,6 +126,7 @@
 		5459A35FCB502D3A65BE88C4A1A7C819 /* GradientActivityIndicatorView+AnimateIsHidden.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = "GradientActivityIndicatorView+AnimateIsHidden.swift"; sourceTree = "<group>"; };
 		59286ACC8816C332C7919AEBF42BC6EB /* GradientLoadingBar.podspec */ = {isa = PBXFileReference; explicitFileType = text.script.ruby; includeInIndex = 1; indentWidth = 2; path = GradientLoadingBar.podspec; sourceTree = "<group>"; tabWidth = 2; xcLanguageSpecificationIdentifier = xcode.lang.ruby; };
 		640E8ABB2313DD280008C5A6 /* Constants.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Constants.swift; sourceTree = "<group>"; };
+		640E8ABD2313E4540008C5A6 /* GradientActivityIndicatorViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GradientActivityIndicatorViewModel.swift; sourceTree = "<group>"; };
 		670D1598351BCDDA2ACA6F3ECB0434BB /* SwiftFormat.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; path = SwiftFormat.xcconfig; sourceTree = "<group>"; };
 		67873E92210DD4E777C49C6E8AEDC108 /* GradientLoadingBar.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = GradientLoadingBar.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		7471906D53E2B2BEDC58FEDF3DC82244 /* Pods-GradientLoadingBar_Example-dummy.m */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.c.objc; path = "Pods-GradientLoadingBar_Example-dummy.m"; sourceTree = "<group>"; };
@@ -302,6 +304,7 @@
 			isa = PBXGroup;
 			children = (
 				8AB9BDBFBE2396FB45EEB12E7B9C6067 /* GradientLoadingBarViewModel.swift */,
+				640E8ABD2313E4540008C5A6 /* GradientActivityIndicatorViewModel.swift */,
 			);
 			name = ViewModel;
 			path = GradientLoadingBar/Classes/ViewModel;
@@ -625,6 +628,7 @@
 				8BD7971BD44E1BB5E96B9BD7F1047F0F /* GradientActivityIndicatorView+AnimateIsHidden.swift in Sources */,
 				B4876567964EBC1B95C76559240D1AAB /* GradientActivityIndicatorView.swift in Sources */,
 				7F0493B920FABFACCE19457C63AD9719 /* GradientLoadingBar-dummy.m in Sources */,
+				640E8ABE2313E4540008C5A6 /* GradientActivityIndicatorViewModel.swift in Sources */,
 				7D00DA81B76090CC52ADBEC7E56F8A4B /* GradientLoadingBarController.swift in Sources */,
 				3F7EF08A0DB32C7543CFDDB67068D548 /* GradientLoadingBarViewModel.swift in Sources */,
 				640E8ABC2313DD280008C5A6 /* Constants.swift in Sources */,

GradientLoadingBar/Classes/ViewModel/GradientActivityIndicatorViewModel.swift

@@ -0,0 +1,73 @@
+//
+//  GradientActivityIndicatorViewModel.swift
+//  GradientLoadingBar
+//
+//  Created by Felix Mau on 08/26/19.
+//  Copyright © 2019 Felix Mau. All rights reserved.
+//
+
+import Foundation
+import LightweightObservable
+
+class GradientActivityIndicatorViewModel {
+    // MARK: - Types
+
+    ///
+    enum AnimationState: Equatable {
+        case none
+        case animating(duration: TimeInterval)
+    }
+
+    // MARK: - Public properties
+
+    ///
+    var animationState: Observable<AnimationState> {
+        return animationStateSubject.asObservable
+    }
+
+    ///
+    var infinteGradientColors: Observable<[CGColor]> {
+        return infinteGradientColorsSubject.asObservable
+    }
+
+    ///
+    var isHidden = false {
+        didSet {
+            if isHidden {
+                animationStateSubject.value = .none
+            } else {
+                animationStateSubject.value = .animating(duration: progressAnimationDuration)
+            }
+        }
+    }
+
+    /// Colors used for the gradient.
+    var gradientColors = UIColor.GradientLoadingBar.gradientColors {
+        didSet {
+            infinteGradientColorsSubject.value = makeInfiniteGradientColors()
+        }
+    }
+
+    /// Duration for the progress animation.
+    var progressAnimationDuration = TimeInterval.GradientLoadingBar.progressDuration
+
+    // MARK: - Private properties
+
+    private let infinteGradientColorsSubject: Variable<[CGColor]> = Variable([])
+
+    private let animationStateSubject: Variable<AnimationState> = Variable(.none)
+
+    // MARK: - Private methods
+
+    /// Simulate infinte animation - Therefore we'll reverse the colors and remove the first and last item
+    /// to prevent duplicate values at the "inner edges" destroying the infinite look.
+    private func makeInfiniteGradientColors() -> [CGColor] {
+        let reversedColors = gradientColors
+            .reversed()
+            .dropFirst()
+            .dropLast()
+
+        let infiniteGradientColors = gradientColors + reversedColors + gradientColors
+        return infiniteGradientColors.map { $0.cgColor }
+    }
+}

GradientLoadingBar/Classes/Views/GradientActivityIndicatorView.swift

@@ -7,6 +7,7 @@
 //
 
 import UIKit
+import LightweightObservable
 
 @IBDesignable
 open class GradientActivityIndicatorView: UIView {
@@ -19,37 +20,32 @@ open class GradientActivityIndicatorView: UIView {
 
     open override var isHidden: Bool {
         didSet {
-            if isHidden {
-                stopProgressAnimation()
-            } else {
-                startProgressAnimation()
-            }
+            viewModel.isHidden = isHidden
         }
     }
 
     /// Duration for the progress animation.
-    public var progressAnimationDuration = TimeInterval.GradientLoadingBar.progressDuration
+    public var progressAnimationDuration: TimeInterval {
+        get {
+            return viewModel.progressAnimationDuration
+        }
+        set {
+            viewModel.progressAnimationDuration = newValue
+        }
+    }
 
     /// Colors used for the gradient.
-    public var gradientColorList = UIColor.GradientLoadingBar.gradientColorList {
-        didSet {
-            gradientLayer.colors = infinteColorList.map { $0.cgColor }
+    public var gradientColors: [UIColor] {
+        get {
+            return viewModel.gradientColors
+        }
+        set {
+            viewModel.gradientColors = newValue
         }
     }
 
     // MARK: - Private properties
 
-    /// Simulate infinte animation - Therefore we'll reverse the colors and remove the first and last item
-    /// to prevent duplicate values at the "inner edges" destroying the infinite look.
-    private var infinteColorList: [UIColor] {
-        let reversedColorList = gradientColorList
-            .reversed()
-            .dropFirst()
-            .dropLast()
-
-        return gradientColorList + reversedColorList + gradientColorList
-    }
-
     /// Layer holding the gradient.
     private var gradientLayer: CAGradientLayer = {
         let layer = CAGradientLayer()
@@ -61,6 +57,12 @@ open class GradientActivityIndicatorView: UIView {
         return layer
     }()
 
+    ///
+    private let viewModel = GradientActivityIndicatorViewModel()
+
+    /// The dispose bag for the observables.
+    private var disposeBag = DisposeBag()
+
     // MARK: - Initializers
 
     public override init(frame: CGRect) {
@@ -102,21 +104,35 @@ open class GradientActivityIndicatorView: UIView {
     // MARK: - Private methods
 
     private func commonInit() {
-        gradientLayer.colors = infinteColorList.map { $0.cgColor }
         layer.insertSublayer(gradientLayer, at: 0)
         layer.masksToBounds = true
 
-        startProgressAnimation()
+        bindViewModelToView()
     }
 
-    private func startProgressAnimation() {
+    private func bindViewModelToView() {
+        viewModel.infinteGradientColors.subscribeDistinct { [weak self] newInfinteGradientColors, _ in
+            self?.gradientLayer.colors = newInfinteGradientColors
+        }.disposed(by: &disposeBag)
+
+        viewModel.animationState.subscribeDistinct { [weak self] newAnimationState, _ in
+            switch newAnimationState {
+            case .none:
+                self?.stopProgressAnimation()
+            case let .animating(duration):
+                self?.startProgressAnimation(duration: duration)
+            }
+        }.disposed(by: &disposeBag)
+    }
+
+    private func startProgressAnimation(duration: TimeInterval) {
         let animation = CABasicAnimation(keyPath: "position")
 
         animation.fromValue = CGPoint(x: -2 * bounds.size.width, y: 0)
         animation.toValue = CGPoint.zero
         animation.isRemovedOnCompletion = false
         animation.repeatCount = Float.infinity
-        animation.duration = progressAnimationDuration
+        animation.duration = duration
 
         gradientLayer.add(animation, forKey: GradientActivityIndicatorView.progressAnimationKey)
     }