Cocoa Programming for OS X: The Big Nerd Ranch Guide

Add Cut, Copy, and Paste to Dice

Let’s add cut, copy, and paste capability to Dice. You will create methods named cut:, copy:, and paste: in the DieView class. To make these methods easier to write, you will first create methods for putting data onto and reading data off of a pasteboard. Reopen your Dice project and in DieView.swift, add these methods to DieView:

    // MARK: - Pasteboard

    func writeToPasteboard(pasteboard: NSPasteboard) {
        if let intValue = intValue {
            pasteboard.clearContents()
            pasteboard.writeObjects(["\(intValue)"])
        }
    }

    func readFromPasteboard(pasteboard: NSPasteboard) -> Bool {
        let objects = pasteboard.readObjectsForClasses([NSString.self],
                                              options: [:]) as! [String]
        if let str = objects.first {
            intValue = str.toInt() ...