krzyzanowskim

import Cocoa

let loremIpsum = """
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque erat risus, laoreet et eros id, lobortis elementum sem. Nullam nec magna massa. Donec gravida felis at odio tincidunt pretium et in orci. Curabitur suscipit porta purus non faucibus. Cras dapibus felis eu enim rutrum, vel aliquet lacus volutpat. Quisque fermentum vulputate dictum. Morbi mattis orci quis dui posuere, id vulputate turpis tempus. Sed vulputate augue at ullamcorper feugiat. Phasellus nec lacus eget sapien congue lacinia vel et nulla. Phasellus sollicitudin gravida dapibus. Donec molestie ullamcorper lacus eu rutrum. Praesent lacinia dignissim dui eu ultricies. Integer in lacus lobortis, porttitor sem eu, tincidunt dolor. Cras dignissim nisl in maximus ullamcorper.

Proin nec vulputate magna. In interdum leo sit amet arcu consequat facilisis. Fusce ut malesuada ante, nec malesuada nisl. Mauris porta velit quis tortor mollis, in suscipit augue efficitur. Praesent eleifend mollis neque, non sempe

krzyzanowskim

struct ContentView: View {
    @State var color: Color = .Pastel.random()

    var body: some View {
        Rectangle()
            .foregroundColor(color)
            .onTapGesture {
                color = .Pastel.random()
            }
    }

krzyzanowskim

extension StringProtocol {
	
	subscript(_ offset: Int) -> String.Element {
		if offset >= 0 {
			self[index(startIndex, offsetBy: offset)]
		} else {
			self[index(endIndex, offsetBy: offset)]			
		}
	}
	

krzyzanowskim

// Excerpt from https://github.com/krzyzanowskim/CoreTextWorkshop
// Licence BSD-2 clause
// Marcin Krzyzanowski marcin@krzyzanowskim.com

func getSizeThatFits(_ attributedString: NSAttributedString, maxWidth: CGFloat) -> CGSize {
    let framesetter = CTFramesetterCreateWithAttributedString(attributedString)
    let rectPath = CGRect(origin: .zero, size: CGSize(width: maxWidth, height: 50000))

    let ctFrame = CTFramesetterCreateFrame(framesetter, CFRange(), CGPath(rect: rectPath, transform: nil), nil)

krzyzanowskim

import Cocoa

/// "given this many pixels and a string with these attributes, tell me the optimal places to do a line break"
class LineBreakPropose: NSObject, NSTextLayoutManagerDelegate {
    
    var lineBreaks: [NSTextLocation] = []
    
    init(_ attributedString: NSAttributedString, in size: CGSize, by lineBreakMode: NSLineBreakMode = .byWordWrapping) {
        super.init() 
        

krzyzanowskim

I noticed that NSTextContainer.lineFragmentPadding value does not affect the NSTextLayoutManager.usageBoundsForTextContainer rectangle on both sizes.

Documentation of lineFragmentPadding says: "The padding appears at the beginning and end of the line fragment rectangles.", however the value of the usageBoundsForTextContainer does not resize appropriately.

Let's see how a different value of lineFragmentPadding affect the text container rectangle:

for lineFragmentPadding = 5 usageBoundsForTextContainer = (x: 5.0, y: 0.0, width: 66.73828125, height: 14.0)

for lineFragmentPadding = 0

krzyzanowskim

I noticed that NSTextLayoutManager.usageBoundsForTextContainer is no longer KVO observable, despite being documented as KVO-compliant.. I believe it worked around macOS 13.

var usageBoundsForTextContainerObserver: NSKeyValueObservation?

usageBoundsForTextContainerObserver = textLayoutManager.observe(\.usageBoundsForTextContainer, options: [.new]) { textLayoutManager, change in
    print("never called")
}

krzyzanowskim

// Documentation says:
//
// > Executes the specified block for each range of a particular attribute in the attributed string.
// 
// documentation is not correct (or implementation, hard to tell). The block is executed at least once, not matter if particular attribute is or is not present in the attributed string.

import Foundation
import AppKit

/// Attributed string without any attribute, in particular no font attribute set

krzyzanowskim

import Foundation

// like FormatStyle but reversible, more like Formatter
protocol ReversibleFormatStyle<FormatOutput>: FormatStyle {
	func format(_ value: FormatOutput) -> FormatInput
}

// Implementation

struct ReversibleNumFormatStyle: ReversibleFormatStyle {

krzyzanowskim

//
//  MultilineLabel.swift
//
//  Created by Marcin Krzyzanowski on 19/09/2019.
//

import UIKit

public class MultilineLabel: UILabel {
  override public init(frame: CGRect) {