Steve2/A2Mac/NSLayoutManager-Extension.swift

86 lines
3.4 KiB
Swift

//
// NSLayoutManager-Extension.swift
// Steve ][
//
// Created by Tamas Rudnai on 9/17/19.
// Copyright © 2019, 2020 Tamas Rudnai. All rights reserved.
//
// This file is part of Steve ][ -- The Apple ][ Emulator.
//
// Steve ][ is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Steve ][ is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Steve ][. If not, see <https://www.gnu.org/licenses/>.
//
import Foundation
import Cocoa
import AppKit
class LayoutManager : NSLayoutManager {
var text: String? { return textStorage?.string }
var font: NSFont = NSFont.systemFont(ofSize: NSFont.systemFontSize) {
didSet {
guard let text = self.text else { return }
let textRange = NSMakeRange(0, (text as NSString).length)
invalidateGlyphs(forCharacterRange: textRange, changeInLength: 0, actualCharacterRange: nil)
invalidateLayout(forCharacterRange: textRange, actualCharacterRange: nil)
}
}
override func drawBackground(forGlyphRange glyphsToShow: NSRange, at origin: CGPoint) {
super.drawBackground(forGlyphRange: glyphsToShow, at:origin)
guard let text = self.text else { return }
enumerateLineFragments(forGlyphRange: glyphsToShow)
{ (rect: CGRect, usedRect: CGRect, textContainer: NSTextContainer, glyphRange: NSRange, stop: UnsafeMutablePointer<ObjCBool>) -> Void in
let characterRange = self.characterRange(forGlyphRange: glyphRange, actualGlyphRange: nil)
// Draw invisible tab space characters
let line = (self.text! as NSString).substring(with: characterRange)
do {
let expr = try NSRegularExpression(pattern: "\t", options: [])
expr.enumerateMatches(in: line, options: [.reportProgress], range: NSRange(location: 0, length: line.count))
{ (result: NSTextCheckingResult?, flags: NSRegularExpression.MatchingFlags, stop: UnsafeMutablePointer<ObjCBool>) in
if let result = result {
let range = NSMakeRange(result.range.location + characterRange.location, result.range.length)
let characterRect = self.boundingRect(forGlyphRange: range, in: textContainer)
let symbol = "\u{21E5}"
let attrs = [NSAttributedString.Key.font : self.font]
let height = (symbol as NSString).size(withAttributes: attrs).height
symbol.draw(in: characterRect.offsetBy(dx: 1.0, dy: height * 0.5), withAttributes: attrs)
}
}
} catch let error as NSError {
print(error.localizedDescription)
}
}
}
}