Merge pull request SDWebImage#633 from hlian/progressive-orientation

SDWebImageDownloaderOperation: pass orientation to initWithCGImage during progressive rendering

Author: Olivier Poitrey

SDWebImage/SDWebImageDownloaderOperation.m

@@ -32,6 +32,7 @@ @interface SDWebImageDownloaderOperation ()
 
 @implementation SDWebImageDownloaderOperation {
     size_t width, height;
+    UIImageOrientation orientation;
     BOOL responseFromCached;
 }
 
@@ -216,12 +217,22 @@ - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
         if (width + height == 0) {
             CFDictionaryRef properties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, NULL);
             if (properties) {
+                NSInteger orientationValue = -1;
                 CFTypeRef val = CFDictionaryGetValue(properties, kCGImagePropertyPixelHeight);
                 if (val) CFNumberGetValue(val, kCFNumberLongType, &height);
                 val = CFDictionaryGetValue(properties, kCGImagePropertyPixelWidth);
                 if (val) CFNumberGetValue(val, kCFNumberLongType, &width);
+                val = CFDictionaryGetValue(properties, kCGImagePropertyOrientation);
+                if (val) CFNumberGetValue(val, kCFNumberNSIntegerType, &orientationValue);
                 CFRelease(properties);
+
+                // When we draw to Core Graphics, we lose orientation information,
+                // which means the image below born of initWithCGIImage will be
+                // oriented incorrectly sometimes. (Unlike the image born of initWithData
+                // in connectionDidFinishLoading.) So save it here and pass it on later.
+                orientation = [[self class] orientationFromPropertyValue:(orientationValue == -1 ? 1 : orientationValue)];
             }
+
         }
 
         if (width + height > 0 && totalSize < self.expectedSize) {
@@ -249,7 +260,7 @@ - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
 #endif
 
             if (partialImageRef) {
-                UIImage *image = [UIImage imageWithCGImage:partialImageRef];
+                UIImage *image = [UIImage imageWithCGImage:partialImageRef scale:1 orientation:orientation];
                 UIImage *scaledImage = [self scaledImageForKey:self.request.URL.absoluteString image:image];
                 image = [UIImage decodedImageWithImage:scaledImage];
                 CGImageRelease(partialImageRef);
@@ -269,6 +280,29 @@ - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
     }
 }
 
++ (UIImageOrientation)orientationFromPropertyValue:(NSInteger)value {
+    switch (value) {
+        case 1:
+            return UIImageOrientationUp;
+        case 3:
+            return UIImageOrientationDown;
+        case 8:
+            return UIImageOrientationLeft;
+        case 6:
+            return UIImageOrientationRight;
+        case 2:
+            return UIImageOrientationUpMirrored;
+        case 4:
+            return UIImageOrientationDownMirrored;
+        case 5:
+            return UIImageOrientationLeftMirrored;
+        case 7:
+            return UIImageOrientationRightMirrored;
+        default:
+            return UIImageOrientationUp;
+    }
+}
+
 - (UIImage *)scaledImageForKey:(NSString *)key image:(UIImage *)image {
     return SDScaledImageForKey(key, image);
 }