From 30fd6cc6ab3d0bdad682bbb952dbca930f6391eb Mon Sep 17 00:00:00 2001
From: DreamPiggy <lizhuoli1126@126.com>
Date: Sat, 21 Oct 2017 23:31:31 +0800
Subject: [PATCH] Implements -[NSImage isGIF] method to return whether current
 NSImage is GIF representation.

---
 SDWebImage/NSImage+WebCache.m | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/SDWebImage/NSImage+WebCache.m b/SDWebImage/NSImage+WebCache.m
index 518b498c..c5a3b8f5 100644
--- a/SDWebImage/NSImage+WebCache.m
+++ b/SDWebImage/NSImage+WebCache.m
@@ -23,7 +23,18 @@
 }
 
 - (BOOL)isGIF {
-    return NO;
+    BOOL isGIF = NO;
+    for (NSImageRep *rep in self.representations) {
+        if ([rep isKindOfClass:[NSBitmapImageRep class]]) {
+            NSBitmapImageRep *bitmapRep = (NSBitmapImageRep *)rep;
+            NSUInteger frameCount = [[bitmapRep valueForProperty:NSImageFrameCount] unsignedIntegerValue];
+            if (frameCount > 1) {
+                isGIF = YES;
+                break;
+            }
+        }
+    }
+    return isGIF;
 }
 
 @end