PlaygroundAlerts.swift

import Cocoa

// Interactive Playground Alert Utilities

public struct WindowManager {
    internal static var screen: NSScreen! = NSScreen.mainScreen()
    internal static var activationToken: dispatch_once_t = 0
    internal static func buildWindow() -> NSWindow {
        dispatch_once(&WindowManager.activationToken) {
            NSApplication.sharedApplication().setActivationPolicy(.Regular) // show icon in dock
        }
        let frame = WindowManager.screen.frame
        let center = CGPointMake(frame.midX, frame.midY)
        let window = NSWindow(); window.setFrameOrigin(center); window.level = 7;
        window.styleMask = NSBorderlessWindowMask;
        window.makeKeyAndOrderFront(nil); window.alphaValue = 0.0
        return window
    }
    
    public static func showInfo(info: String) {
        let alert = NSAlert(); alert.messageText = info
        alert.beginSheetModalForWindow(WindowManager.buildWindow(), completionHandler: nil)
    }
    
    // NSModalResponseStop, NSModalResponseAbort, NSModalResponseContinue
    public static func queryBool(question: String, completion: (Bool) -> Void) {
        let alert = NSAlert(); alert.messageText = question
        alert.addButtonWithTitle("Yes")
        alert.addButtonWithTitle("No")
        alert.beginSheetModalForWindow(WindowManager.buildWindow()) {
            (response) -> Void in
            completion(response == abs(NSModalResponseStop))
        }
    }
    
    public static func queryText(question: String, completion: (String) -> Void) {
        let alert = NSAlert(); alert.messageText = question
        alert.addButtonWithTitle("Okay")
        alert.addButtonWithTitle("Cancel")
        let input = NSTextField(frame: CGRectMake(0, 0, 200, 24))
        alert.accessoryView = input
        alert.beginSheetModalForWindow(WindowManager.buildWindow()) {
            (response) -> Void in
            if response == abs(NSModalResponseStop) {
                completion(input.stringValue)
            }
        }
    }
}