Toggle selectedRange attributes in UITextView

Question

I have created a button that I want to check if text is selected then if so toggle bold and unbold over the selectedRange when tapped. At the moment my code will just change the

Answer 1

This might do the trick:

func toggleBold() {
    if let textRange = selectedRange {

        let attributedString = NSAttributedString(attributedString: noteContents.attributedText)

        //Enumerate all the fonts in the selectedRange
        attributedString.enumerateAttribute(.font, in: textRange, options: []) { (font, range, pointee) in
            let newFont: UIFont
            if let font = font as? UIFont {
                if font.fontDescriptor.symbolicTraits.contains(.traitBold) { //Was bold => Regular
                    newFont = UIFont.systemFont(ofSize: font.pointSize, weight: .regular)
                } else { //Wasn't bold => Bold
                    newFont = UIFont.systemFont(ofSize: font.pointSize, weight: .bold)
                }
            } else { //No font was found => Bold
                newFont = UIFont.systemFont(ofSize: 17, weight: .bold) //Default bold
            }
            noteContents.textStorage.addAttributes([.font : newFont], range: textRange)
        }
    }
}

We use enumerateAttribute(_:in:options:using:) to look for fonts (since bold/non-bold) is in that attribute. We change it according to your needs (bold <=> unbold).