element-ios/Riot/Categories/NSAttributedString.swift

54 lines
2.4 KiB
Swift

//
// Copyright 2022-2024 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only
// Please see LICENSE in the repository root for full details.
//
import Foundation
public extension NSAttributedString {
/// Returns a new attributed string by removing all links from the receiver.
@objc var vc_byRemovingLinks: NSAttributedString {
let result = NSMutableAttributedString(attributedString: self)
result.removeAttribute(.link, range: NSRange(location: 0, length: length))
return result
}
/// Enumerate attribute for given key and conveniently ignore any attribute that doesn't match given generic type.
///
/// - Parameters:
/// - attrName: The name of the attribute to enumerate.
/// - enumerationRange: The range over which the attribute values are enumerated. If omitted, the entire range is used.
/// - opts: The options used by the enumeration. For possible values, see NSAttributedStringEnumerationOptions.
/// - block: The block to apply to ranges of the specified attribute in the attributed string.
func vc_enumerateAttribute<T>(_ attrName: NSAttributedString.Key,
in enumerationRange: NSRange? = nil,
options opts: NSAttributedString.EnumerationOptions = [],
using block: (T, NSRange, UnsafeMutablePointer<ObjCBool>) -> Void) {
self.enumerateAttribute(attrName,
in: enumerationRange ?? .init(location: 0, length: length),
options: opts) { (attr: Any?, range: NSRange, stop: UnsafeMutablePointer<ObjCBool>) in
guard let typedAttr = attr as? T else { return }
block(typedAttr, range, stop)
}
}
/// Creates a new attributed string with given alpha applied to all texts.
///
/// - Parameters:
/// - alpha: Alpha value to apply
/// - Returns: New attributed string with updated alpha
@objc func withTextColorAlpha(_ alpha: CGFloat) -> NSAttributedString {
let mutableString = NSMutableAttributedString(attributedString: self)
mutableString.vc_enumerateAttribute(.foregroundColor) { (color: UIColor, range: NSRange, _) in
let colorWithAlpha = color.withAlphaComponent(alpha)
mutableString.addAttribute(.foregroundColor, value: colorWithAlpha, range: range)
}
return mutableString
}
}