Added convenience API

Examples/ImagesExample/ImagesExample/ViewController.swift

@@ -11,17 +11,8 @@ import PlaceholderKit
 
 class ViewController: UIViewController {
     var sampleImagesCollectionViewController: SampleImagesCollectionViewController?
-    let placeholders: [Placeholder] = [
-        Placeholder(size: CGSize(width: 100, height: 100), backgroundStyle: .solidColor(.red)),
-        Placeholder(size: CGSize(width: 200, height: 100), backgroundStyle: .solidColor(.blue)),
-        Placeholder(size: CGSize(width: 100, height: 200), backgroundStyle: .solidColor(.green)),
-        Placeholder(size: CGSize(width: 320, height: 480), backgroundStyle: .solidColor(.yellow)),
-        Placeholder(size: CGSize(width: 320, height: 480), backgroundStyle: .image(UIImage(named: "background")!))
-    ]
 
-    lazy var images: [UIImage] = {
-        return placeholders.compactMap({$0.render()})
-    }()
+    let images: [UIImage] = PlaceholderKit.defaultPlaceholders
 
     override func viewDidLoad() {
         super.viewDidLoad()

Sources/PlaceholderKit/PlaceholderKit.swift

@@ -18,6 +18,132 @@ public typealias Image = UIImage
 public typealias Font = UIFont
 #endif
 
+public struct PlaceholderKit {
+    public static let defaultPalette = ColorPalette(name: "defaultPalette",
+                                             colors: [
+                                                UIColor("ff5a5a"),
+                                                UIColor("ff7b5a"),
+                                                UIColor("ffb65a"),
+                                                UIColor("ced07d"),
+                                                UIColor("7dd0b6")
+        ])
+
+    public static let defaultSizes = [
+        CGSize(width: 320, height: 320),
+        CGSize(width: 320, height: 480),
+        CGSize(width: 480, height: 320),
+        CGSize(width: 320, height: 569),
+        CGSize(width: 569, height: 320),
+        ]
+
+    public static var defaultPreset: RandomColorPreset {
+        return RandomColorPreset(name: "defaultPreset",
+                                 colorPalette: defaultPalette,
+                                 sizes: defaultSizes)
+    }
+
+    public static var defaultPlaceholders: [UIImage] {
+        return defaultPreset.placeholders.compactMap({$0.render()})
+    }
+}
+
+public struct ColorPalette {
+    let name: String
+    let colors: [Color]
+
+    var looper: LoopAroundIterator<Color> {
+        return LoopAroundIterator(sequence: colors, current: 0)
+    }
+
+    public init(name: String, colors: [Color]) {
+        self.name = name
+        self.colors = colors
+    }
+}
+
+public enum AspectRatio: CaseIterable {
+    case r1x1
+    case r2x3
+    case r3x2
+    case r4x5
+    case r5x4
+    case r9x16
+    case r16x9
+
+    var value: Double {
+        switch self {
+        case .r1x1:
+            return 1.0
+        case .r2x3:
+            return 0.6666
+        case .r3x2:
+            return 1.5
+        case .r4x5:
+            return 0.8
+        case .r5x4:
+            return 1.25
+        case .r9x16:
+            return 0.5625
+        case .r16x9:
+            return 1.7778
+        }
+    }
+
+    var displayString: String {
+        switch self {
+        case .r1x1:
+            return "1:1"
+        case .r2x3:
+            return "2:3"
+        case .r3x2:
+            return "3:2"
+        case .r4x5:
+            return "4:5"
+        case .r5x4:
+            return "5:4"
+        case .r9x16:
+            return "9:16"
+        case .r16x9:
+            return "16:9"
+        }
+    }
+}
+
+public struct RandomColorPreset {
+    let name: String
+    let colorPalette: ColorPalette
+    let sizes: [CGSize]
+
+    public var placeholders: [Placeholder] {
+        let colorSequence = AnySequence { self.colorPalette.looper }
+        let placeholders = zip(sizes, colorSequence)
+            .map({Placeholder(size: $0,
+                              backgroundStyle: .solidColor($1))})
+        return placeholders
+    }
+
+    public init(name: String,
+                colorPalette: ColorPalette,
+                sizes: [CGSize]) {
+        self.name = name
+        self.colorPalette = colorPalette
+        self.sizes = sizes
+    }
+}
+
+public struct LoopAroundIterator<T>: IteratorProtocol {
+    let sequence: [T]
+    var current = 0
+
+    mutating public func next() -> T? {
+        guard 0..<sequence.count ~= current else { return nil }
+
+        let item = sequence[current]
+        current = (current + 1) % sequence.count
+        return item
+    }
+}
+
 public struct Placeholder {
     let size: CGSize
     let backgroundStyle: BackgroundStyle
@@ -41,7 +167,13 @@ public struct Placeholder {
     }
 
     public var displayedText: String {
-        return "\(Int(size.width))x\(Int(size.height))"
+        let pointSizeString = "\(Int(size.width))x\(Int(size.height))"
+
+        // find nearest aspect ratio
+        let ratio = size.width / size.height
+        let nearestRatio = AspectRatio.allCases.first(where: {abs(CGFloat($0.value) - ratio) < 0.005})
+
+        return [pointSizeString, nearestRatio?.displayString].compactMap({$0}).joined(separator: " | ")
     }
 
     public var textRect: CGRect {
@@ -65,11 +197,6 @@ public enum BackgroundStyle {
     case image(Image)
 }
 
-public enum BackgroundStrategy {
-    case randomColor
-    case randomImage
-}
-
 public enum TextLocationStrategy {
     case center
     case topRight
@@ -82,3 +209,21 @@ public enum TextSizeFormatStrategy {
     case points
     case aspectRatio
 }
+
+public extension Color {
+    public convenience init(_ hexString: String, alpha: CGFloat = 1) {
+        let hex = hexString.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)
+        var int = UInt32()
+        Scanner(string: hex).scanHexInt32(&int)
+        let r, g, b: UInt32
+        switch hex.count {
+        case 3: // RGB (12-bit)
+            (r, g, b) = ((int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
+        case 6: // RGB (24-bit)
+            (r, g, b) = (int >> 16, int >> 8 & 0xFF, int & 0xFF)
+        default:
+            (r, g, b) = (1, 1, 0)
+        }
+        self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(255 * alpha) / 255)
+    }
+}