passforios/pass/UserInterface/UICodeHighlightingLabel.swift
2019-01-20 21:04:04 -08:00

48 lines
1.7 KiB
Swift

/*
UICodeHighlightingLabel.swift
pass
Created by Danny Moesch on 20.01.19.
Copyright © 2019 Bob Sun. All rights reserved.
*/
import UIKit
import passKit
class UICodeHighlightingLabel: UILocalizedLabel {
private static let CODE_ATTRIBUTES: [NSAttributedString.Key: Any] = [.font: UIFont(name: "Menlo-Regular", size: 12)!]
private static let ATTRIBUTED_NEWLINE = NSAttributedString(string: "\n")
override func awakeFromNib() {
super.awakeFromNib()
guard let text = text else {
return
}
attributedText = formatCode(in: text)
}
/// Format code sections in a multiline string block.
///
/// A line in the string is interpreted as a code section if it starts with two spaces.
///
/// - Parameter text: Multiline string block
/// - Returns: Same multiline string block with code sections formatted
private func formatCode(in text: String) -> NSMutableAttributedString {
let formattedText = text
.split(omittingEmptySubsequences: false) {
$0 == "\n" || $0 == "\r\n"
}.map { line -> NSAttributedString in
if line.starts(with: " ") {
return NSAttributedString(string: String(line), attributes: UICodeHighlightingLabel.CODE_ATTRIBUTES)
}
return NSAttributedString(string: String(line))
}.reduce(into: NSMutableAttributedString(string: "")) {
$0.append($1)
$0.append(UICodeHighlightingLabel.ATTRIBUTED_NEWLINE)
}
formattedText.deleteCharacters(in: NSRange(location: formattedText.length - 1, length: 1))
return formattedText
}
}