NSString sizeWithAttributes: content rect - cocoa

Question

How do I get a NSString's size as if it drew in an NSRect. The problem is when I try -[NSString sizeWithAttributes:], it returns an NSSize as if it had infinite width. I want to give a maximum width to the method. Is there any way of doing so? (BTW: Mac OS, not iPhone OS)
Thanks,
Alex

Answer 1

float heightForStringDrawing(NSString *myString, NSFont *myFont,
float myWidth)
{
NSTextStorage *textStorage = [[[NSTextStorage alloc] initWithString:myString] autorelease];
NSTextContainer *textContainer = [[[NSTextContainer alloc] initWithContainerSize:NSMakeSize(myWidth, FLT_MAX)] autorelease];
;
NSLayoutManager *layoutManager = [[[NSLayoutManager alloc] init] autorelease];
[layoutManager addTextContainer:textContainer];
[textStorage addLayoutManager:layoutManager];
[textStorage addAttribute:NSFontAttributeName value:myFont
range:NSMakeRange(0, [textStorage length])];
[textContainer setLineFragmentPadding:0.0];
(void) [layoutManager glyphRangeForTextContainer:textContainer];
return [layoutManager
usedRectForTextContainer:textContainer].size.height;
}
It was in the docs after all. Thank you Joshua anyway!

Answer 2

I revised Alexandre Cassagne's answer for iOS with ARC enabled.
CGSize ACMStringSize(NSString *string, UIFont *font, CGSize size)
{
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithString:string];
[textStorage addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, [textStorage length])];
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:size];
textContainer.lineFragmentPadding = 0;
[layoutManager addTextContainer:textContainer];
[textStorage addLayoutManager:layoutManager];
return [layoutManager usedRectForTextContainer:textContainer].size;
}

Answer 3

I believe your only option here is NSLayoutManager and asking for a union of the used rects for a given glyph range.

Answer 4

for OSX cocoa/Swift 4:
(using a custom NSview, to show also how to draw)
//
// CustomView.swift
// DrawMyString
//
// Created by ing.conti on 19/10/2018.
// Copyright © 2018 com.ingconti. All rights reserved.
//
import Cocoa
class CustomView: NSView {
override func draw(_ dirtyRect: NSRect) {
super.draw(dirtyRect)
let s : NSString = "AA BB CC DD EE FF"
let W = 50
let size = NSSize(width: W, height: 100)
let boundingRectWithSize = s.boundingRect(with: size, options: .usesLineFragmentOrigin, attributes: [:])
let r = NSRect(origin: CGPoint(x: 20, y: 30), size: boundingRectWithSize.size)
s.draw(in: r, withAttributes: [:])
r.frame()
}
}
(we also draw border, to see it)