A source list cell that correct colours the label text of a drag image when selected

SourceListTableCellView.swift

class SourceListTableCellView: NSTableCellView {
    override var draggingImageComponents: [NSDraggingImageComponent] {
        let components = super.draggingImageComponents
        guard
            self.backgroundStyle == .emphasized, //emphasized = selected
            let textField = self.textField,
            let newStyle = textField.attributedStringValue.mutableCopy() as? NSMutableAttributedString,
            let labelIndex = components.firstIndex(where: { $0.key == .label })
        else {
            return components
        }

        //Set to the label colour and draw
        newStyle.addAttribute(.foregroundColor, value: NSColor.labelColor, range: NSMakeRange(0, newStyle.length))
        let image = NSImage(size: textField.bounds.size, flipped: false) { (rect) -> Bool in
            newStyle.draw(in: rect)
            return true
        }

        //We'll just update the label contents as everything else is already setup for us
        components[labelIndex].contents = image

        return components
    }
}