From a2eab4f34552dc738c3cbf9308ed0144c327fe22 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jer=C3=B4me=20Morissard?= <jmo@Bushwick.local>
Date: Thu, 31 Oct 2013 18:18:22 +0100
Subject: [PATCH] [SDWebImage] 	Try to use an the previous cached image for
 placeholder

---
 SDWebImage/SDWebImageManager.h    |  5 +++++
 SDWebImage/UIImageView+WebCache.h | 13 ++++++++++++-
 SDWebImage/UIImageView+WebCache.m | 13 +++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/SDWebImage/SDWebImageManager.h b/SDWebImage/SDWebImageManager.h
index b54af25e9..4c27eaadb 100644
--- a/SDWebImage/SDWebImageManager.h
+++ b/SDWebImage/SDWebImageManager.h
@@ -182,4 +182,9 @@ SDWebImageManager *manager = [SDWebImageManager sharedManager];
  */
 - (BOOL)diskImageExistsForURL:(NSURL *)url;
 
+/**
+ * Key for URL
+ */
+- (NSString *)cacheKeyForURL:(NSURL *)url;
+
 @end
diff --git a/SDWebImage/UIImageView+WebCache.h b/SDWebImage/UIImageView+WebCache.h
index 952a1e9df..cd9b5450d 100644
--- a/SDWebImage/UIImageView+WebCache.h
+++ b/SDWebImage/UIImageView+WebCache.h
@@ -54,10 +54,21 @@
  */
 - (void)setImageWithURL:(NSURL *)url;
 
+/**
+ * Set the imageView `image` with an `url` and a optionaly placeholder image.
+ *
+ * The download is asynchronous and cached.
+ *
+ * @param url The url for the image.
+ * @param placeholder The image to be set initially, until the image request finishes.
+ * @see setImageWithPreviousCachedImageWithURL:andPlaceholderImage:
+ */
+- (void)setImageWithPreviousCachedImageWithURL:(NSURL *)url andPlaceholderImage:(UIImage *)placeholder;
+
 /**
  * Set the imageView `image` with an `url` and a placeholder.
  *
- * The downloand is asynchronous and cached.
+ * The download is asynchronous and cached.
  *
  * @param url The url for the image.
  * @param placeholder The image to be set initially, until the image request finishes.
diff --git a/SDWebImage/UIImageView+WebCache.m b/SDWebImage/UIImageView+WebCache.m
index 7df6af87c..99100ee30 100644
--- a/SDWebImage/UIImageView+WebCache.m
+++ b/SDWebImage/UIImageView+WebCache.m
@@ -8,12 +8,25 @@
 
 #import "UIImageView+WebCache.h"
 #import "objc/runtime.h"
+#import "SDWebImageManager.h"
 
 static char operationKey;
 static char operationArrayKey;
 
 @implementation UIImageView (WebCache)
 
+- (void)setImageWithPreviousCachedImageWithURL:(NSURL *)url andPlaceholderImage:(UIImage *)placeholder
+{
+    NSString *key = [[SDWebImageManager sharedManager] cacheKeyForURL:url];
+    UIImage *lastPreviousCachedImage = [[SDImageCache sharedImageCache] imageFromDiskCacheForKey:key];
+    if (nil == lastPreviousCachedImage) {
+        [self setImageWithURL:url placeholderImage:placeholder options:0 progress:nil completed:nil];
+    }
+    else {
+        [self setImageWithURL:url placeholderImage:lastPreviousCachedImage options:0 progress:nil completed:nil];
+    }
+}
+
 - (void)setImageWithURL:(NSURL *)url
 {
     [self setImageWithURL:url placeholderImage:nil options:0 progress:nil completed:nil];