Merge pull request #3535 from dreampiggy/feature/SDAnimatedImage_scale

Update the implementation `SDScaledImageForScaleFactor` to support SDAnimatedImage

SDWebImage/Core/SDImageCache.m

@@ -262,7 +262,7 @@ static NSString * _defaultDiskCacheDirectory;
             SDImageFormat format = image.sd_imageFormat;
             if (format == SDImageFormatUndefined) {
                 // If image is animated, use GIF (APNG may be better, but has bugs before macOS 10.14)
-                if (image.sd_isAnimated) {
+                if (image.sd_imageFrameCount > 1) {
                     format = SDImageFormatGIF;
                 } else {
                     // If we do not have any data to detect image format, check whether it contains alpha channel to use PNG or JPEG format
@@ -461,7 +461,7 @@ static NSString * _defaultDiskCacheDirectory;
     if (image) {
         if (options & SDImageCacheDecodeFirstFrameOnly) {
             // Ensure static image
-            if (image.sd_isAnimated) {
+            if (image.sd_imageFrameCount > 1) {
 #if SD_MAC
                 image = [[NSImage alloc] initWithCGImage:image.CGImage scale:image.scale orientation:kCGImagePropertyOrientationUp];
 #else
@@ -593,7 +593,7 @@ static NSString * _defaultDiskCacheDirectory;
     if (image) {
         if (options & SDImageCacheDecodeFirstFrameOnly) {
             // Ensure static image
-            if (image.sd_isAnimated) {
+            if (image.sd_imageFrameCount > 1) {
 #if SD_MAC
                 image = [[NSImage alloc] initWithCGImage:image.CGImage scale:image.scale orientation:kCGImagePropertyOrientationUp];
 #else

SDWebImage/Core/SDWebImageDefine.m

@@ -9,6 +9,7 @@
 #import "SDWebImageDefine.h"
 #import "UIImage+Metadata.h"
 #import "NSImage+Compatibility.h"
+#import "SDAnimatedImage.h"
 #import "SDAssociatedObject.h"
 
 #pragma mark - Image scale
@@ -81,6 +82,24 @@ inline UIImage * _Nullable SDScaledImageForScaleFactor(CGFloat scale, UIImage *
         return image;
     }
     UIImage *scaledImage;
+    // Check SDAnimatedImage support for shortcut
+    if ([image.class conformsToProtocol:@protocol(SDAnimatedImage)]) {
+        if ([image respondsToSelector:@selector(animatedCoder)]) {
+            id<SDAnimatedImageCoder> coder = [(id<SDAnimatedImage>)image animatedCoder];
+            if (coder) {
+                scaledImage = [[image.class alloc] initWithAnimatedCoder:coder scale:scale];
+            }
+        } else {
+            // Some class impl does not support `animatedCoder`, keep for compatibility
+            NSData *data = [(id<SDAnimatedImage>)image animatedImageData];
+            if (data) {
+                scaledImage = [[image.class alloc] initWithData:data scale:scale];
+            }
+        }
+        if (scaledImage) {
+            return scaledImage;
+        }
+    }
     if (image.sd_isAnimated) {
         UIImage *animatedImage;
 #if SD_UIKIT || SD_WATCH