How to set letter spacing of UITextField

Solution 1:

No need to go for attributedText, which to be honest, was a mess implementing with modified spacing. As soon as I closed the keyboard the spacing disappeared, which prompted me to dig further.

Every UITextField has a property called defaultTextAttributes, which according to Apple "returns a dictionary of text attributes with default values.". The Apple document also says that "this property applies the specified attributes to the entire text of the text field"

Just find a suitable place in your code, usually where the textfield is being initialized and then copy and paste the following.

Answered in Swift 3.0

textfield.defaultTextAttributes.updateValue(spacing, forKey: NSKernAttributeName)

where spacing is of CGFloat type. For example 2.0

This works for different fonts as well.

Cheers!!

The latest syntax seems to be:

 yourField.defaultTextAttributes.updateValue(36.0, 
     forKey: NSAttributedString.Key.kern)

Solution 2:

This is what eventually worked to set the kern for every change

    textField.addTarget(self, action: "textFieldDidChange", forControlEvents: .EditingChanged)

    func textFieldDidChange () {    
        let attributedString = NSMutableAttributedString(string: textField.text)
        attributedString.addAttribute(NSKernAttributeName, value: 5, range: NSMakeRange(0, count(textField.text)))
        attributedString.addAttribute(NSFontAttributeName, value: font, range: NSMakeRange(0, count(textField.text)))
        attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.blackColor(), range: NSMakeRange(0, count(textField.text)))

        textField.attributedText = attributedString
    }

    func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {

        if count(textField.text) < 4 {
            return true
            // Else if 4 and delete is allowed
        }else if count(string) == 0 {
            return true
            // Else limit reached
        }else{
            return false
        }
    }

The problem however remains because different numbers have different widths, I will just resort back to making a UITextField for every digit.

Solution 3:

Use the defaultTextAttributes property of UITextField. It will handle the conversion to NSAttributedString for you and apply the attributes you set. For example:

    NSMutableDictionary *attrs = [self.textField.defaultTextAttributes mutableCopy];
[attrs addEntriesFromDictionary:@{
    NSKernAttributeName: @18,
    NSUnderlineColorAttributeName: [UIColor grayColor],
    NSUnderlineStyleAttributeName: @(NSUnderlineStyleSingle | NSUnderlinePatternDash)
}];
self.textField.defaultTextAttributes = attrs;