74 lines
2.5 KiB
Swift
74 lines
2.5 KiB
Swift
import CryptoSwift
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public class PlaceholderIcon {
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private let seed: Int
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// Colour palette
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private var colours: [UIColor] = [
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0x5ff8b0,
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0x26cdb9,
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0xf3c615,
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0xfcac5a
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].map { UIColor(hex: $0) }
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init(seed: Int, colours: [UIColor]? = nil) {
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self.seed = seed
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if let colours = colours { self.colours = colours }
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}
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convenience init(seed: String, colours: [UIColor]? = nil) {
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// Ensure we have a correct hash
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var hash = seed
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if (hash.matches("^[0-9A-Fa-f]+$") && hash.count >= 12) { hash = seed.sha512() }
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guard let number = Int(hash.substring(to: 12), radix: 16) else {
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owsFailDebug("Failed to generate number from seed string: \(seed).")
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self.init(seed: 0, colours: colours)
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return
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}
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self.init(seed: number, colours: colours)
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}
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public func generateLayer(with diameter: CGFloat, text: String) -> CALayer {
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let colour = self.colours[seed % self.colours.count].cgColor
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let base = getTextLayer(with: diameter, colour: colour, text: text)
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base.masksToBounds = true
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return base
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}
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private func getTextLayer(with diameter: CGFloat, colour: CGColor? = nil, text: String) -> CALayer {
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let text = text.capitalized
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let font = UIFont.boldSystemFont(ofSize: diameter / 2)
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let height = NSString(string: text).boundingRect(with: CGSize(width: diameter, height: CGFloat.greatestFiniteMagnitude),
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options: .usesLineFragmentOrigin, attributes: [ NSAttributedString.Key.font : font ], context: nil).height
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let frame = CGRect(x: 0, y: (diameter - height) / 2, width: diameter, height: height)
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let layer = CATextLayer()
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layer.frame = frame
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layer.foregroundColor = UIColor.white.cgColor
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layer.contentsScale = UIScreen.main.scale
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let fontName = font.fontName
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let fontRef = CGFont(fontName as CFString)
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layer.font = fontRef
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layer.fontSize = font.pointSize
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layer.alignmentMode = .center
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layer.string = text
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let base = CALayer()
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base.frame = CGRect(x: 0, y: 0, width: diameter, height: diameter)
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base.backgroundColor = colour
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base.addSublayer(layer)
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return base
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}
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}
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private extension String {
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func matches(_ regex: String) -> Bool {
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return self.range(of: regex, options: .regularExpression, range: nil, locale: nil) != nil
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}
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}
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