Add an optional configuration struct for layout

Author: Anna-Mariia Shkarlinska

CarLensCollectionViewLayout.xcodeproj/project.pbxproj

@@ -17,6 +17,7 @@
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 		9518383C21E4FFCA00BEA6EB /* CollectionViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9518383B21E4FFCA00BEA6EB /* CollectionViewCell.swift */; };
+		9518384821E623E800BEA6EB /* CarLensCollectionViewLayoutOptions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9518384721E623E800BEA6EB /* CarLensCollectionViewLayoutOptions.swift */; };
 		955E4FD421CBFB2800B4C3BB /* CarLensCollectionViewLayout.h in Headers */ = {isa = PBXBuildFile; fileRef = 955E4FD221CBFB2800B4C3BB /* CarLensCollectionViewLayout.h */; settings = {ATTRIBUTES = (Public, ); }; };
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@@ -56,6 +57,7 @@
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 		9518383B21E4FFCA00BEA6EB /* CollectionViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CollectionViewCell.swift; sourceTree = "<group>"; };
+		9518384721E623E800BEA6EB /* CarLensCollectionViewLayoutOptions.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CarLensCollectionViewLayoutOptions.swift; sourceTree = "<group>"; };
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@@ -126,6 +128,7 @@
 			children = (
 				955E4FD221CBFB2800B4C3BB /* CarLensCollectionViewLayout.h */,
 				9505725D21D4D8FB009EA422 /* CarLensCollectionViewLayout.swift */,
+				9518384721E623E800BEA6EB /* CarLensCollectionViewLayoutOptions.swift */,
 				958D17BF21D66DF00067BED6 /* CarLensCollectionViewCell.swift */,
 				9505725F21D4D922009EA422 /* CarLensLayoutAttributes.swift */,
 				955E4FD321CBFB2800B4C3BB /* Info.plist */,
@@ -256,6 +259,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				9518384821E623E800BEA6EB /* CarLensCollectionViewLayoutOptions.swift in Sources */,
 				9505725E21D4D8FB009EA422 /* CarLensCollectionViewLayout.swift in Sources */,
 				958D17C021D66DF00067BED6 /* CarLensCollectionViewCell.swift in Sources */,
 				9505726021D4D922009EA422 /* CarLensLayoutAttributes.swift in Sources */,

CarLensCollectionViewLayout/CarLensCollectionViewLayout.swift

@@ -11,6 +11,8 @@ public final class CarLensCollectionViewLayout: UICollectionViewFlowLayout {
 
     private var firstSetupDone = false
 
+    private let options: CarLensCollectionViewLayoutOptions
+    
     /// SeeAlso: UICollectionViewFlowLayout
     public override func prepare() {
         super.prepare()
@@ -19,14 +21,30 @@ public final class CarLensCollectionViewLayout: UICollectionViewFlowLayout {
         firstSetupDone = true
     }
 
+    
+    /// The initialization of the CarLensCollectionViewLayout.
+    ///
+    /// - Parameters:
+    ///   - options: An optional additional configuration of the layout.
+    public init(options: CarLensCollectionViewLayoutOptions = CarLensCollectionViewLayoutOptions()) {
+        self.options = options
+        super.init()
+    }
+    
+    public required init?(coder aDecoder: NSCoder) {
+        self.options = CarLensCollectionViewLayoutOptions()
+        super.init(coder: aDecoder)
+    }
+    
     private func setup() {
         guard let collectionView = collectionView else { return }
         scrollDirection = .horizontal
-        minimumLineSpacing = 20
-        itemSize = CGSize(width: collectionView.bounds.width - 80, height: collectionView.bounds.height)
-        let inset = (collectionView.bounds.width - itemSize.width) / 2
-        collectionView.contentInset = .init(top: 0, left: inset, bottom: 0, right: inset)
-        collectionView.decelerationRate = UIScrollView.DecelerationRate.fast
+        minimumLineSpacing = options.minimumSpacing
+        itemSize = CGSize(width: collectionView.bounds.width - 60, height: collectionView.bounds.height)
+        let sidesInset = (collectionView.bounds.width - itemSize.width) / 2
+        collectionView.contentInset =  .init(top: 0, left: sidesInset, bottom: 0, right: sidesInset)
+        collectionView.decelerationRate = options.decelerationRate
+        collectionView.showsHorizontalScrollIndicator = options.shouldShowScrollIndicator
     }
 
     /// SeeAlso: UICollectionViewFlowLayout

CarLensCollectionViewLayout/CarLensCollectionViewLayoutOptions.swift

@@ -0,0 +1,34 @@
+//
+//  CarLensCollectionViewLayoutOptions.swift
+//  CarLensCollectionViewLayout
+//
+//  Copyright © 2019 Netguru. All rights reserved.
+//
+
+import Foundation
+
+/// The optional configuration of CarLensCollectionViewLayout.
+public struct CarLensCollectionViewLayoutOptions {
+    
+    /// A minimum spacing between cells.
+    let minimumSpacing: CGFloat
+    
+    /// A deceleration for a scroll view.
+    let decelerationRate: UIScrollView.DecelerationRate
+    
+    /// A value indicating whether collection view should have a scroll indicator.
+    let shouldShowScrollIndicator: Bool
+    
+    /// The initialization of the optional layout configuration.
+    ///
+    /// - Parameters:
+    ///   - minimumSpacing: A minimum spacing between cells. The default value is `20`.
+    ///   - decelerationRate: A deceleration for a scroll view. The default value is `.fast`.
+    ///   - shouldShowScrollIndicator: A value indicating whether collection view should have a scroll indicator. The default value is `false`.
+    public init(minimumSpacing: CGFloat = 20, decelerationRate: UIScrollView.DecelerationRate = UIScrollView.DecelerationRate.fast, shouldShowScrollIndicator: Bool = false) {
+        self.minimumSpacing = minimumSpacing
+        self.decelerationRate = decelerationRate
+        self.shouldShowScrollIndicator = shouldShowScrollIndicator
+    }
+
+}