Merge pull request #37 from hyperoslo/fix/unwrapping-crash

Fix/unwrapping crash
zenangst · Nov 8, 2016 · 844e29f · 844e29f
2 parents d44a273 + b734eae
commit 844e29f
Showing 1 changed file with 19 additions and 12 deletions.
diff --git a/Source/Mac/NSImage+Hue.swift b/Source/Mac/NSImage+Hue.swift
@@ -13,31 +13,38 @@ class CountedColor {
 extension NSImage {
 
   fileprivate func resize(_ newSize: CGSize) -> NSImage {
+    guard newSize.width > 0.0 && newSize.height > 0.0 else { return NSImage() }
+
     let scaledImage = NSImage(size: newSize)
     scaledImage.lockFocus()
     let ctx = NSGraphicsContext.current()
     ctx?.imageInterpolation = .high
     draw(in: NSMakeRect(0, 0, newSize.width, newSize.height), from: NSRect.zero, operation: .copy, fraction: 1)
     scaledImage.unlockFocus()
-    
+
     return scaledImage
   }
 
   public func colors(_ scaleDownSize: CGSize? = nil) -> (background: NSColor, primary: NSColor, secondary: NSColor, detail: NSColor) {
-    let cgImage: CGImage
+    let cgImage: CGImage?
 
     if let scaleDownSize = scaleDownSize {
       let context = NSGraphicsContext.current()
-      cgImage = resize(scaleDownSize).cgImage(forProposedRect: nil, context: context, hints: nil)!
+      cgImage = resize(scaleDownSize).cgImage(forProposedRect: nil, context: context, hints: nil)
     } else {
       let context = NSGraphicsContext.current()
       let ratio = size.width / size.height
       let r_width: CGFloat = 250
-      cgImage = resize(CGSize(width: r_width, height: r_width / ratio)).cgImage(forProposedRect: nil, context: context, hints: nil)!
+      cgImage = resize(CGSize(width: r_width, height: r_width / ratio)).cgImage(forProposedRect: nil, context: context, hints: nil)
     }
 
-    let width = cgImage.width
-    let height = cgImage.height
+    guard let resolvedImage = cgImage else { return (background: NSColor.clear,
+                                                     primary: NSColor.clear,
+                                                     secondary: NSColor.clear,
+                                                     detail: NSColor.clear) }
+
+    let width = resolvedImage.width
+    let height = resolvedImage.height
     let bytesPerPixel = 4
     let bytesPerRow = width * bytesPerPixel
     let bitsPerComponent = 8
@@ -48,7 +55,7 @@ extension NSImage {
     let raw = malloc(bytesPerRow * height)
     let bitmapInfo = CGImageAlphaInfo.premultipliedFirst.rawValue
     let context = CGContext(data: raw, width: width, height: height, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow, space: colorSpace, bitmapInfo: bitmapInfo)
-    context?.draw(cgImage, in: CGRect(x: 0, y: 0, width: CGFloat(width), height: CGFloat(height)))
+    context?.draw(resolvedImage, in: CGRect(x: 0, y: 0, width: CGFloat(width), height: CGFloat(height)))
     let rawData = context?.data?.assumingMemoryBound(to: UInt8.self)
     let imageBackgroundColors = NSCountedSet(capacity: height)
     let imageColors = NSCountedSet(capacity: width * height)
@@ -80,7 +87,7 @@ extension NSImage {
         imageColors.add(color)
       }
     }
-    
+
     var sortedColors = [CountedColor]()
 
     for color in imageBackgroundColors {
@@ -133,18 +140,18 @@ extension NSImage {
 
       if primaryColor == nil &&
         color.isContrastingWith(imageBackgroundColor) {
-          primaryColor = color
+        primaryColor = color
       } else if secondaryColor == nil &&
         primaryColor != nil &&
         primaryColor!.isDistinctFrom(color) &&
         color.isContrastingWith(imageBackgroundColor) {
-          secondaryColor = color
+        secondaryColor = color
       } else if secondaryColor != nil &&
         (secondaryColor!.isDistinctFrom(color) &&
           primaryColor!.isDistinctFrom(color) &&
           color.isContrastingWith(imageBackgroundColor)) {
-            detailColor = color
-            break
+        detailColor = color
+        break
       }
     }