From 3ef0f609fd42281c2adc86592932a53d0cd39f84 Mon Sep 17 00:00:00 2001
From: Sebastian Vieira <vieira@gmail.com>
Date: Tue, 17 Jan 2012 16:34:44 +0100
Subject: [PATCH] checking if uiimage supports the scale parameter for retina
 display phones (only supported form ios 4 onwards)

---
 SDImageCache.m         | 11 +++++++----
 SDWebImageDownloader.m |  8 ++++++--
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/SDImageCache.m b/SDImageCache.m
index be9e7d80..3bf426d9 100644
--- a/SDImageCache.m
+++ b/SDImageCache.m
@@ -174,11 +174,14 @@ static SDImageCache *instance;
     NSData *imageData = [NSData dataWithContentsOfFile:file];
     if (imageData) {
         UIImage *image = [[[UIImage alloc] initWithData:imageData ] autorelease];
-        CGFloat scale = 1.0;
-        if ([fileKey hasSuffix:@"@2x.png"] || [fileKey hasSuffix:@"@2x.jpg"]) {
-            scale = 2.0;
+        if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
+            CGFloat scale = 1.0;
+            if ([fileKey hasSuffix:@"@2x.png"] || [fileKey hasSuffix:@"@2x.jpg"]) {
+                scale = 2.0;
+            }
+            image = [[[UIImage alloc] initWithCGImage:image.CGImage scale:scale orientation:UIImageOrientationUp] autorelease];
         }
-        return [[[UIImage alloc] initWithCGImage:image.CGImage scale:scale orientation:UIImageOrientationUp] autorelease];
+        return image;
     }
     return nil;
 }
diff --git a/SDWebImageDownloader.m b/SDWebImageDownloader.m
index 737e2bd5..bded6aec 100644
--- a/SDWebImageDownloader.m
+++ b/SDWebImageDownloader.m
@@ -131,8 +131,12 @@ NSString *const SDWebImageDownloadStopNotification = @"SDWebImageDownloadStopNot
             scale = 2.0;
         }
         
-        UIImage *image = [[[UIImage alloc] initWithData:imageData ] autorelease];
-        image = [[UIImage alloc] initWithCGImage:image.CGImage scale:scale orientation:UIImageOrientationUp];
+        UIImage *image = [[UIImage alloc] initWithData:imageData ];
+        if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
+            UIImage *originalImage = image;
+            image = [[UIImage alloc] initWithCGImage:originalImage.CGImage scale:scale orientation:UIImageOrientationUp];
+            [originalImage release];
+        }
 
 #ifdef ENABLE_SDWEBIMAGE_DECODER
         [[SDWebImageDecoder sharedImageDecoder] decodeImage:image withDelegate:self userInfo:nil];