Drawing images with CGContext and NSGraphicsContext in Swift

cocoa-drawing.swift

//: Playground - noun: a place where people can play

import Cocoa

let bounds = CGRectMake(0, 0, 100, 100);

func DrawImageInCGContext(#size: CGSize, #drawFunc: (context: CGContextRef) -> ()) -> NSImage {
    let colorSpace = CGColorSpaceCreateDeviceRGB()
    let bitmapInfo = CGBitmapInfo(CGImageAlphaInfo.PremultipliedLast.rawValue)
    let context = CGBitmapContextCreate(
        nil,
        Int(size.width),
        Int(size.height),
        8,
        0,
        colorSpace,
        bitmapInfo)
    
    drawFunc(context: context)
    
    let image = CGBitmapContextCreateImage(context)
    return NSImage(CGImage: image, size: size)
}

func DrawImageInNSGraphicsContext(#size: CGSize, #drawFunc: ()->()) -> NSImage {
    let rep = NSBitmapImageRep(
        bitmapDataPlanes: nil,
        pixelsWide: Int(size.width),
        pixelsHigh: Int(size.height),
        bitsPerSample: 8,
        samplesPerPixel: 4,
        hasAlpha: true,
        isPlanar: false,
        colorSpaceName: NSCalibratedRGBColorSpace,
        bytesPerRow: 0,
        bitsPerPixel: 0)
    
    let context = NSGraphicsContext(bitmapImageRep: rep!)
    
    NSGraphicsContext.saveGraphicsState()
    NSGraphicsContext.setCurrentContext(context)
    
    drawFunc()
    
    NSGraphicsContext.restoreGraphicsState()
    
    let image = NSImage(size: size)
    image.addRepresentation(rep!)
    
    return image
}

let rect = CGRectMake(0, 0, 100, 20)

let image1 = DrawImageInCGContext(size: rect.size) { (context) -> () in
    CGContextSetFillColorWithColor(context, NSColor.redColor().CGColor)
    CGContextFillRect(context, rect);
}

let image2 = DrawImageInNSGraphicsContext(size: rect.size) { () -> () in
    NSColor.blueColor().set()
    NSRectFill(rect)
}

Thanks