How do you adjust text kerning using Interface Builder in Xcode 7?
Create a subclass of UILabel call it KerningLabel have it be comprised of the following code:
import UIKit
@IBDesignable
class KerningLabel: UILabel {
@IBInspectable var kerning: CGFloat = 0.0 {
didSet {
if attributedText?.length == nil { return }
let attrStr = NSMutableAttributedString(attributedString: attributedText!)
let range = NSMakeRange(0, attributedText!.length)
attrStr.addAttributes([NSAttributedStringKey.kern: kerning], range: range)
attributedText = attrStr
}
}
}
Drag out a label. Change it to your UILabel subclass. Adjust the kerning as desired.
In obj-c:
.h
IB_DESIGNABLE
@interface KerningLabel : UILabel
@property (nonatomic) IBInspectable CGFloat kerning;
@end
.m
@implementation KerningLabel
- (void)setKerning:(CGFloat)kerning
{
_kerning = kerning;
if(self.attributedText)
{
NSMutableAttributedString *attribString = [[NSMutableAttributedString alloc]initWithAttributedString:self.attributedText];
[attribString addAttribute:NSKernAttributeName value:@(kerning) range:NSMakeRange(0, self.attributedText.length)];
self.attributedText = attribString;
}
}
@end
You can actually do this without the use of a subclass through an extension.
import UIKit
@IBDesignable
extension UILabel {
@IBInspectable
public var kerning:CGFloat {
set{
if let currentAttibutedText = self.attributedText {
let attribString = NSMutableAttributedString(attributedString: currentAttibutedText)
attribString.addAttributes([NSKernAttributeName:newValue], range:NSMakeRange(0, currentAttibutedText.length))
self.attributedText = attribString
}
} get {
var kerning:CGFloat = 0
if let attributedText = self.attributedText {
attributedText.enumerateAttribute(NSKernAttributeName,
in: NSMakeRange(0, attributedText.length),
options: .init(rawValue: 0)) { (value, range, stop) in
kerning = value as? CGFloat ?? 0
}
}
return kerning
}
}
}
While this won't actually show up in interface builder it will show up and work when you run your app.