Fixed an issue where button's setTitle(string:state:) did not respond to a title change.

[mixdesign]

Hi, @codeido
Thanks for accepting my PR.

We have a problem in previous PR's implementation 😶:
Everythings works OK if the developer configures the button only through the storyboard.
But, if there is a need to change the title of the button programmatically, then a problem arises:

button.setTitle("Button title", for: .normal) // Won't change the title

The cause of the problem was the getAttributedString() method, which always returned the value .attributedText and ignored the value of .text;

I fixed the issue.
Now we have a flexible function:

// Get the NSMutableAttributedString with kern value: optional("string") ?? "";
// Button's previous attributedText is kept, only mutableString value is changed.
private func getAttributedString(with string:String?, letterSpacing spacing:CGFloat) -> NSMutableAttributedString {
    var attr:NSMutableAttributedString!
    if let string = string, let attrText = self.titleLabel?.attributedText {
        let attrString = NSMutableAttributedString(attributedString:attrText)
        attrString.mutableString.setString(string)
        attr = attrString
    } else {
        attr = NSMutableAttributedString(string:string ?? "")
    }
    
    attr.addAttribute(NSAttributedStringKey.kern, value: spacing, range: NSRange(location: 0, length: attr.length))
    return attr
}

In the future PR with another attributed string features, we may create another common private function which will return titleLabel's NSMutableAttributedString with a single string parameter.

Thanks!

[mixdesign]

I forgot to mension override method in PMSuperButton, which is self explanatory:

override open func setTitle(_ title: String?, for state: UIControlState) {
    // setTitle always sets attributed text
    self.setAttributedTitle(getAttributedString(with: title, letterSpacing: letterSpacing), for: state)
}

What do you think, is it ok always setting the attributed string for titleLabel ?

[pmusolino]

Ohh thanks for this fix. What happens if the user wants to set a custom attributed title? Did he lose all the changes?

[pmusolino]

I tested your solution, but I think that this can be better:

@IBInspectable open var letterSpacing: CGFloat = 0 {
        didSet {
            self.setTitle(self.titleLabel?.text, for: self.state)
        }
    }

override open func setTitle(_ title: String?, for state: UIControlState) {
        // setTitle always sets attributed text
        if let title = title{
            let attributedStr = NSMutableAttributedString(string: title)
            self.setAttributedTitle(attributedStr, for: self.state)
        }
    }
    
open override func setAttributedTitle(_ title: NSAttributedString?, for state: UIControlState) {
        if let titleAttributed = title{
            let mutableAttributedString = NSMutableAttributedString(attributedString: titleAttributed)
            mutableAttributedString.addAttribute(NSAttributedStringKey.kern, value: letterSpacing, range: NSRange(location: 0, length: mutableAttributedString.length))
            super.setAttributedTitle(mutableAttributedString, for: state)
        }
        else{
            super.setAttributedTitle(title, for: state)
        }
    }

This solution works on all cases that I tested and is more simple and elegant + in future can be added more IBInspectable variables that need use the setAttributedString override method.

What do you think?

[pmusolino]

In reality, this fixes not manage all the cases, for example, the color change and other adjustments on UIButton. I think we need to remove the letter spacing feature, at least for now.

[mixdesign]

@codeido, I think we can solve this problem. Let's continue the discussion until we find the best solution. I will try to prepare another solution till the end of this week.

[pmusolino]

Excellent @mixdesign, consider that everything that impacts the text needs to be "converted" in a NSAttributedString with this approach.

[mixdesign]

Hey, @codeido
What do you think about this implementation: https://github.com/mixdesign/PMSuperButton/blob/master/Sources/PMSuperButton.swift

It works well with various combinations of programmatically calling setTitle, setAttributedTitle, setTitleColor.

I'm still testing it on my real project, just keep an eye by now.