files.swift

import CoreFoundation
import CoreGraphics
import CoreText

var font = CTFontCreateWithName(("Lucida Grande" as! CFString), 12, nil)
var attrs = CFDictionaryCreateMutable(nil, 0,
                                         [kCFCopyStringDictionaryKeyCallBacks],
                                         [kCFTypeDictionaryValueCallBacks])
CFDictionaryAddValue(attrs,
                     Unmanaged.passUnretained(kCTFontAttributeName).toOpaque(),
                     Unmanaged.passUnretained(font).toOpaque())

var s = "This is a test string."
for cc in 0..<10 {
	s += " This is a test string."
}
var cfas = CFAttributedStringCreate(nil, s as! CFString, nil)//attrs)
print("\(cfas)")
var fs = CTFramesetterCreateWithAttributedString(cfas!)
var range = CFRangeMake(0, CFAttributedStringGetLength(cfas))
var unused = CFRange()
var size = CTFramesetterSuggestFrameSizeWithConstraints(fs, range, nil,
	CGSize.init(width: 200, height: CGFloat.greatestFiniteMagnitude),
	&unused)
print("suggested size \(size)")
var rect = CGRect(origin: CGPoint.init(x: 5, y: 2.5), size: size)
print("path rect \(rect)")
var path = CGPath(rect: rect, transform: nil)
var frame = CTFramesetterCreateFrame(fs, range, path, nil)

var pathbb = path.boundingBoxOfPath
print("path bounding box \(pathbb)")

var lines = CTFrameGetLines(frame)
var n = CFArrayGetCount(lines)
range.length = 1
print("\(n) lines")
var th: CGFloat = 0
for i in 0..<n {
	range.location = i
	var p = CGPoint.zero
	CTFrameGetLineOrigins(frame, range, &p)
	var ll = CFArrayGetValueAtIndex(lines, i)
	var l = Unmanaged<CTLine>.fromOpaque(ll!).takeUnretainedValue()
	var asc: CGFloat = 0
	var des: CGFloat = 0
	var lea: CGFloat = 0
	var wid = CTLineGetTypographicBounds(l, &asc, &des, &lea)
	print("line \(i): \(lea)")
	print("\ty+ascent \(p.y + asc)")
	print("\ty-descent \(p.y - des)")
	th += asc + des + lea
}
print("total height \(th)")

output.txt

Optional(This is a test string. This is a test string. This is a test string. This is a test string. This is a test string. This is a test string. This is a test string. This is a test string. This is a test string. This is a test string. This is a test string.{
})
suggested size (199.634765625, 105.0)
path rect (5.0, 2.5, 199.634765625, 105.0)
path bounding box (5.0, 2.5, 199.634765625, 105.0)
7 lines
line 0: 0.0
	y+ascent 102.240234375
	y-descent 90.240234375
line 1: 0.0
	y+ascent 87.240234375
	y-descent 75.240234375
line 2: 0.0
	y+ascent 72.240234375
	y-descent 60.240234375
line 3: 0.0
	y+ascent 57.240234375
	y-descent 45.240234375
line 4: 0.0
	y+ascent 42.240234375
	y-descent 30.240234375
line 5: 0.0
	y+ascent 27.240234375
	y-descent 15.240234375
line 6: 0.0
	y+ascent 12.240234375
	y-descent 0.240234375
total height 84.0