Various improvements

submodules/TelegramUI/Components/AvatarBackground/Sources/AvatarBackground.swift

@@ -0,0 +1,57 @@
+import Foundation
+import UIKit
+import Display
+import GradientBackground
+
+public enum AvatarBackground: Equatable {
+    public static let defaultBackgrounds: [AvatarBackground] = [
+        .gradient([0xFF5A7FFF, 0xFF2CA0F2, 0xFF4DFF89, 0xFF6BFCEB]),
+        .gradient([0xFFFF011D, 0xFFFF530D, 0xFFFE64DC, 0xFFFFDC61]),
+        .gradient([0xFFFE64DC, 0xFFFF6847, 0xFFFFDD02, 0xFFFFAE10]),
+        .gradient([0xFF84EC00, 0xFF00B7C2, 0xFF00C217, 0xFFFFE600]),
+        .gradient([0xFF86B0FF, 0xFF35FFCF, 0xFF69FFFF, 0xFF76DEFF]),
+        .gradient([0xFFFAE100, 0xFFFF54EE, 0xFFFC2B78, 0xFFFF52D9]),
+        .gradient([0xFF73A4FF, 0xFF5F55FF, 0xFFFF49F8, 0xFFEC76FF]),
+    ]
+    
+    case gradient([UInt32])
+    
+    public var colors: [UInt32] {
+        switch self {
+        case let .gradient(colors):
+            return colors
+        }
+    }
+    
+    public var isLight: Bool {
+        switch self {
+            case let .gradient(colors):
+                if colors.count == 1 {
+                    return UIColor(rgb: colors.first!).lightness > 0.99
+                } else if colors.count == 2 {
+                    return UIColor(rgb: colors.first!).lightness > 0.99 || UIColor(rgb: colors.last!).lightness > 0.99
+                } else {
+                    var lightCount = 0
+                    for color in colors {
+                        if UIColor(rgb: color).lightness > 0.99 {
+                            lightCount += 1
+                        }
+                    }
+                    return lightCount >= 2
+                }
+        }
+    }
+    
+    public func generateImage(size: CGSize) -> UIImage {
+        switch self {
+            case let .gradient(colors):
+                if colors.count == 1 {
+                    return generateSingleColorImage(size: size, color: UIColor(rgb: colors.first!))!
+                } else if colors.count == 2 {
+                    return generateGradientImage(size: size, colors: colors.map { UIColor(rgb: $0) }, locations: [0.0, 1.0])!
+                } else {
+                    return GradientBackgroundNode.generatePreview(size: size, colors: colors.map { UIColor(rgb: $0) })
+                }
+        }
+    }
+}