Change NSTextField font size to fit - cocoa

Question

Is there anything like the UILabel's adjustsFontSizeToFitWidth that can be used with a NSTextField?

Answer 1

In short: no. You have to do some brute force work to determine a string's -sizeWithAttributes: -boundingRectWithSize:options:attributes: with a given font size (set as an NSFont for NSFontAttributeName).
I'd start with a standard system font size and work down or up from there, depending on whether it's smaller or larger than the desired rectangle.

Answer 2

Swift 4 solution:
It will resize one by one until it fits, or until minimumFontSize = 3.
let minimumFontSize = 3
var sizeNotOkay = true
var attempt = 0
while sizeNotOkay || attempt < 15 { // will try 15 times maximun
let expansionRect = textField.expansionFrame(withFrame: textField.frame)
let truncated = !NSEqualRects(NSRect.zero, expansionRect)
if truncated {
if let actualFontSize : CGFloat = textField.font?.fontDescriptor.object(forKey: NSFontDescriptor.AttributeName.size) as? CGFloat {
textField.font = NSFont.systemFont(ofSize: actualFontSize - 1)
if actualFontSize < minimumFontSize {
break
}
}
} else {
sizeNotOkay = false
}
attempt += 1
}

Answer 3

I came up with my own solution (its not a good solution!, just in case anyone couldn't find a better solution)
extension NSTextField {
func fontSizeToFit() {
if stringValue.count > 90 {
font = NSFont.systemFont(ofSize: 40)
} else {
font = NSFont.systemFont(ofSize: CGFloat(120 - stringValue.count))
}
}
}