preferredFontForTextStyle for each content size

DynamicTypePlayground.swift

//: Playground - noun: a place where people can play

/*
This playground prints CSV with all font sizes for each content size category and text style.
*/

import UIKit
import XCPlayground

/*
 Hack UIApplication's private preferredContentSizeCategory.

 Force it to change content size so -preferredFontForTextStyle returns
 the font with right descriptor
*/
func changeContentSize(value: String) {
    UIApplication.sharedApplication().setValue(value, forKey: "preferredContentSizeCategory")
}

let textStyles = [
    UIFontTextStyleHeadline,
    UIFontTextStyleSubheadline,
    UIFontTextStyleBody,
    UIFontTextStyleFootnote,
    UIFontTextStyleCaption1,
    UIFontTextStyleCaption2,
    UIFontTextStyleTitle1,
    UIFontTextStyleTitle2,
    UIFontTextStyleTitle3
]

let categories = [
    // Standard
    UIContentSizeCategoryExtraSmall,
    UIContentSizeCategorySmall,
    UIContentSizeCategoryMedium,
    UIContentSizeCategoryLarge,
    UIContentSizeCategoryExtraLarge,
    UIContentSizeCategoryExtraExtraLarge,
    UIContentSizeCategoryExtraExtraExtraLarge,
    
    // Larger text sizes
    UIContentSizeCategoryAccessibilityMedium,
    UIContentSizeCategoryAccessibilityLarge,
    UIContentSizeCategoryAccessibilityExtraLarge,
    UIContentSizeCategoryAccessibilityExtraExtraLarge,
    UIContentSizeCategoryAccessibilityExtraExtraExtraLarge
]

print("#,Content Size Category,Text Style,Font size")

var i = 1
for category in categories {
    changeContentSize(category)
    
    for style in textStyles {
        let font = UIFont.preferredFontForTextStyle(style)
        
        print("\(i),\(category),\(style),\(font.pointSize)pt")
        
        i++
    }
}