Merge pull request onevcat#1060 from xspyhack/master

Refactor AnimatedImageView

Sources/Image/GIFAnimatedImage.swift

@@ -88,14 +88,7 @@ class GIFAnimatedImage {
                 gifDuration = .infinity
             } else {
                 // Get current animated GIF frame duration
-                guard let properties = CGImageSourceCopyPropertiesAtIndex(imageSource, i, nil)
-                    as? [String: Any] else
-                {
-                    return nil
-                }
-
-                let gifInfo = properties[kCGImagePropertyGIFDictionary as String] as? [String: Any]
-                gifDuration += GIFAnimatedImage.getFrameDuration(from: gifInfo)
+                gifDuration += GIFAnimatedImage.getFrameDuration(from: imageSource, at: i)
             }
             images.append(KingfisherWrapper.image(cgImage: imageRef, scale: options.scale, refImage: nil))
             if options.onlyFirstFrame { break }
@@ -104,7 +97,7 @@ class GIFAnimatedImage {
         self.duration = gifDuration
     }
 
-    //Calculates frame duration for a gif frame out of the kCGImagePropertyGIFDictionary dictionary.
+    // Calculates frame duration for a gif frame out of the kCGImagePropertyGIFDictionary dictionary.
     static func getFrameDuration(from gifInfo: [String: Any]?) -> TimeInterval {
         let defaultFrameDuration = 0.1
         guard let gifInfo = gifInfo else { return defaultFrameDuration }
@@ -116,4 +109,13 @@ class GIFAnimatedImage {
         guard let frameDuration = duration else { return defaultFrameDuration }
         return frameDuration.doubleValue > 0.011 ? frameDuration.doubleValue : defaultFrameDuration
     }
+
+    // Calculates frame duration at a specific index for a gif from an `imageSource`.
+    static func getFrameDuration(from imageSource: CGImageSource, at index: Int) -> TimeInterval {
+        guard let properties = CGImageSourceCopyPropertiesAtIndex(imageSource, index, nil)
+            as? [String: Any] else { return 0.0 }
+
+        let gifInfo = properties[kCGImagePropertyGIFDictionary as String] as? [String: Any]
+        return getFrameDuration(from: gifInfo)
+    }
 }

Sources/Image/ImageDrawing.swift

@@ -525,3 +525,77 @@ extension KingfisherWrapper where Base: Image {
     }
     #endif
 }
+
+extension CGImage: KingfisherCompatible {}
+/// High Performance Image Resizing
+/// @see https://nshipster.com/image-resizing/
+extension KingfisherWrapper where Base: CGImage {
+    var size: CGSize {
+        return CGSize(width: CGFloat(base.width), height: CGFloat(base.height))
+    }
+
+    /// Resizes `base` CGImage to a CGImage of new size, respecting the given content mode.
+    ///
+    /// - Parameters:
+    ///   - targetSize: The target size in point.
+    ///   - contentMode: Content mode of output image should be.
+    /// - Returns: A CGImage with new size.
+    #if os(iOS) || os(tvOS)
+    public func resize(to size: CGSize, for contentMode: UIView.ContentMode) -> CGImage {
+        switch contentMode {
+        case .scaleAspectFit:
+            return resize(to: size, for: .aspectFit)
+        case .scaleAspectFill:
+            return resize(to: size, for: .aspectFill)
+        default:
+            return resize(to: size)
+        }
+    }
+    #endif
+
+    // MARK: - Resize
+    /// Resizes `base` CGImage to a CGImage with new size.
+    ///
+    /// - Parameter size: The target size in point.
+    /// - Returns: A CGImage with new size.
+    public func resize(to size: CGSize) -> CGImage {
+        let alphaInfo = base.alphaInfo.rawValue & CGBitmapInfo.alphaInfoMask.rawValue
+        var hasAlpha = false
+        if alphaInfo == CGImageAlphaInfo.premultipliedLast.rawValue
+            || alphaInfo == CGImageAlphaInfo.premultipliedFirst.rawValue
+            || alphaInfo == CGImageAlphaInfo.first.rawValue
+            || alphaInfo == CGImageAlphaInfo.last.rawValue {
+            hasAlpha = true
+        }
+
+        var bitmapInfo = CGImageByteOrderInfo.order32Little.rawValue
+        bitmapInfo |= hasAlpha ? CGImageAlphaInfo.premultipliedFirst.rawValue : CGImageAlphaInfo.noneSkipFirst.rawValue
+
+        guard let context = CGContext(data: nil,
+                                      width: Int(size.width),
+                                      height: Int(size.height),
+                                      bitsPerComponent: base.bitsPerComponent,
+                                      bytesPerRow: base.bytesPerRow,
+                                      space: base.colorSpace ?? CGColorSpaceCreateDeviceRGB(),
+                                      bitmapInfo: bitmapInfo) else
+        {
+            return base
+        }
+
+        let rect = CGRect(origin: .zero, size: size)
+        context.interpolationQuality = .high
+        context.draw(base, in: rect)
+        return context.makeImage() ?? base
+    }
+
+    /// Resizes `base` CGImage to a CGImage of new size, respecting the given content mode.
+    ///
+    /// - Parameters:
+    ///   - targetSize: The target size in point.
+    ///   - contentMode: Content mode of output image should be.
+    /// - Returns: A CGImage with new size.
+    public func resize(to targetSize: CGSize, for contentMode: ContentMode) -> CGImage {
+        let newSize = size.kf.resize(to: targetSize, for: contentMode)
+        return resize(to: newSize)
+    }
+}