update for Swift 1.2, Xcode 6.3

Author: mattneub

bk2ch02p052mars/ch15p406mars/ViewController.swift

@@ -67,7 +67,7 @@ class ViewController : UIViewController {
         delay (2) {
             iv.image = UIImage(named:"bottle5.png")
             // if we're using constraints...
-            // the image view is resized setting the image changes the intrinsic content size
+            // the image view is resized, because setting the image changes the intrinsic content size
         }
 
     }

bk2ch02p057imageRendering/imageRendering/ViewController.swift

@@ -7,19 +7,6 @@ class ViewController : UIViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
 
-        /*
-        Very cool. In seed 5, Swift understands this correctly as needing a double unwrap.
-        I have not said what class the delegate is, and the window var is optional,
-        so we don't know the getter is even implemented.
-        So we must unwrap twice: once because we think there is a window var,
-        and again because we think there is a real UIWindow there.
-*/
-        
-        /*
-        Very uncool. Now (seed 7) they've gone too far.
-        Not only is delegate itself now an optional that needs unwrapping, but
-        window must be unwrapped twice.
-*/
 
         if let window = UIApplication.sharedApplication().delegate!.window! {
             window.tintColor = UIColor.redColor()

bk2ch02p059sixBlueCircles/ch15p411sixBlueCircles/Views.swift

@@ -57,7 +57,7 @@ class MyImageView2 : UIImageView {
 //        let im = UIGraphicsGetImageFromCurrentImageContext()
 //        UIGraphicsEndImageContext()
 
-        self.image = drawnImage()(CGSizeMake(100,100)) {
+        self.image = imageOfSize(CGSizeMake(100,100)) {
             let con = UIGraphicsGetCurrentContext()
             CGContextAddEllipseInRect(con, CGRectMake(0,0,100,100))
             CGContextSetFillColorWithColor(con, UIColor.blueColor().CGColor)
@@ -78,28 +78,11 @@ UIGraphicsEndImageContext()
 Since the purpose is to extract the image, it would be nice to replace that with a functional architecture that clearly yields the image. Moreover, such an architecture has the advantage of isolating any local variables used within the "sandwich". In Objective-C you can at least wrap the interior in curly braces to form a scope, but Swift, with its easy closure formation, offers the opportunity for an even clearer presentation, along these lines:
 */
 
-func imageOfSize(size:CGSize, closure:() -> ()) -> UIImage {
-    UIGraphicsBeginImageContextWithOptions(size, false, 0)
+func imageOfSize(size:CGSize, opaque:Bool = false, closure:() -> ()) -> UIImage {
+    UIGraphicsBeginImageContextWithOptions(size, opaque, 0)
     closure()
     let result = UIGraphicsGetImageFromCurrentImageContext()
     UIGraphicsEndImageContext()
     return result
 }
 
-/*
-In the above, I've assumed that the context is not opaque (second parameter is false). If we want to specify that explicitly, we can, but it would be nice to have to specify it always - we'd like the opaque parameter to be optional. But you can't have an optional second parameter and a third closure parameter. The solution is to curry the function into two sets of parameters:
-*/
-
-func drawnImage (opaque:Bool = false) -> (CGSize, () -> ()) -> UIImage {
-    func imageOfSize(size:CGSize, closure:() -> ()) -> UIImage {
-        UIGraphicsBeginImageContextWithOptions(size, opaque, 0)
-        closure()
-        let result = UIGraphicsGetImageFromCurrentImageContext()
-        UIGraphicsEndImageContext()
-        return result
-    }
-    return imageOfSize
-}
-
-
-

bk2ch02p070filters/ch15p419filters/ViewController.swift

@@ -33,7 +33,7 @@ class ViewController : UIViewController {
 
         // two ways to obtain final bitmap
 
-        let which = 2
+        let which = 1
         switch which {
         case 1:
             let moicg = CIContext(options: nil).createCGImage(blendimage, fromRect: moiextent)

bk2ch02p071BlurAndVibrancy/BlurAndVibrancy/ViewController.swift

@@ -22,7 +22,7 @@ class ViewController: UIViewController {
         blur.frame = mainview.bounds
         blur.autoresizingMask = .FlexibleWidth | .FlexibleHeight
         let vib = UIVisualEffectView(effect: UIVibrancyEffect(
-            forBlurEffect: blur.effect as UIBlurEffect))
+            forBlurEffect: blur.effect as! UIBlurEffect))
         let lab = UILabel()
         lab.text = "Hello, world!"
         lab.sizeToFit()

bk2ch02p077drawingInUIView/ch15p427drawingInUIView/MyView.swift

@@ -3,13 +3,14 @@ import UIKit
 
 class MyView : UIView {
 
-    override init() {
+    init() {
         super.init(frame:CGRectZero)
         self.opaque = false
     }
 
     required init(coder: NSCoder) {
-        fatalError("NSCoding not supported")
+        super.init(coder: coder)
+        self.opaque = false
     }
 
     override init(frame: CGRect) {
@@ -18,7 +19,7 @@ class MyView : UIView {
     }
 
     override func drawRect(rect: CGRect) {
-        let which = 6
+        let which = 1
         switch which {
         case 1:
             let con = UIGraphicsGetCurrentContext()