Trim the first character in NSMutableAttributedString

Question

I am using NSMutableAttributedString to show an attribute string in a label. Is there a way to trim the first character of NSMutableAttributedString without changing the attributes.

Answer 1

No, because one of the attributes of the attributes is the range of the string in which they operate, and those become invalid if the length of the string changes.

A better approach would be to restore the attribute string from scratch, which can be simple or complex, depending on whether you know the attributes you are adding.

Answer 2

NSMutableAttributedStringsupports the method deleteCharacters(in:NSRange):

@IBOutlet weak var topLabel: NSTextField!
@IBOutlet weak var bottomLabel: NSTextField!
...
    let textAttributes : [String : Any] = [
        NSForegroundColorAttributeName : NSColor.blue,
        NSFontAttributeName : NSFont(name: "Menlo", size: 12.0)!
    ]
    let text = NSMutableAttributedString(string: "ABCDEF",
                                         attributes: textAttributes)
    topLabel.attributedStringValue = text
    text.deleteCharacters(in: NSMakeRange(0,1))
    bottomLabel.attributedStringValue = text
...