From 94b15ce80475fd4e5c4dc5ac85461a2e5b148547 Mon Sep 17 00:00:00 2001
From: CHEN Xian'an <xianan.chen@gmail.com>
Date: Sat, 3 May 2014 22:37:22 +0800
Subject: [PATCH 1/2] opportunity for entity to provide image, marks
 imageCache:wantsSourceImageForEntity:withFormatName:completionBlock optional

---
 FastImageCache/FICEntity.h     |  9 +++++++++
 FastImageCache/FICImageCache.h |  4 ----
 FastImageCache/FICImageCache.m | 18 +++++++++++++++---
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/FastImageCache/FICEntity.h b/FastImageCache/FICEntity.h
index fec135d..04ad9b0 100644
--- a/FastImageCache/FICEntity.h
+++ b/FastImageCache/FICEntity.h
@@ -7,6 +7,7 @@
 //
 
 #import "FICImports.h"
+@class FICImageFormat;
 
 typedef void (^FICEntityImageDrawingBlock)(CGContextRef context, CGSize contextSize);
 
@@ -74,4 +75,12 @@ typedef void (^FICEntityImageDrawingBlock)(CGContextRef context, CGSize contextS
  */
 - (FICEntityImageDrawingBlock)drawingBlockForImage:(UIImage *)image withFormatName:(NSString *)formatName;
 
+@optional
+/**
+ Returns the image for a format
+ 
+ @param format The image format that identifies which image table is requesting the source image.
+ */
+- (UIImage *)imageForFormat:(FICImageFormat *)format;
+
 @end
diff --git a/FastImageCache/FICImageCache.h b/FastImageCache/FICImageCache.h
index f8ae039..8b88405 100644
--- a/FastImageCache/FICImageCache.h
+++ b/FastImageCache/FICImageCache.h
@@ -227,8 +227,6 @@ typedef void (^FICImageRequestCompletionBlock)(UIImage *sourceImage);
  */
 @protocol FICImageCacheDelegate <NSObject>
 
-@required
-
 /**
  This method is called on the delegate when the image cache needs a source image.
  
@@ -257,8 +255,6 @@ typedef void (^FICImageRequestCompletionBlock)(UIImage *sourceImage);
  */
 - (void)imageCache:(FICImageCache *)imageCache wantsSourceImageForEntity:(id <FICEntity>)entity withFormatName:(NSString *)formatName completionBlock:(FICImageRequestCompletionBlock)completionBlock;
 
-@optional
-
 /**
  This method is called on the delegate when the image cache has received an image retrieval cancellation request.
  
diff --git a/FastImageCache/FICImageCache.m b/FastImageCache/FICImageCache.m
index 2d8ae98..36f3b7b 100644
--- a/FastImageCache/FICImageCache.m
+++ b/FastImageCache/FICImageCache.m
@@ -27,6 +27,7 @@ @interface FICImageCache () {
     NSMutableDictionary *_requests;
     __weak id <FICImageCacheDelegate> _delegate;
     
+    BOOL _delegateImplementsWantsSourceImageForEntityWithFormatNameCompletionBlock;
     BOOL _delegateImplementsShouldProcessAllFormatsInFamilyForEntity;
     BOOL _delegateImplementsErrorDidOccurWithMessage;
     BOOL _delegateImplementsCancelImageLoadingForEntityWithFormatName;
@@ -46,6 +47,7 @@ - (void)setDelegate:(id<FICImageCacheDelegate>)delegate {
     if (delegate != _delegate) {
         _delegate = delegate;
         
+        _delegateImplementsWantsSourceImageForEntityWithFormatNameCompletionBlock = [_delegate respondsToSelector:@selector(imageCache:wantsSourceImageForEntity:withFormatName:completionBlock:)];
         _delegateImplementsShouldProcessAllFormatsInFamilyForEntity = [_delegate respondsToSelector:@selector(imageCache:shouldProcessAllFormatsInFamily:forEntity:)];
         _delegateImplementsErrorDidOccurWithMessage = [_delegate respondsToSelector:@selector(imageCache:errorDidOccurWithMessage:)];
         _delegateImplementsCancelImageLoadingForEntityWithFormatName = [_delegate respondsToSelector:@selector(imageCache:cancelImageLoadingForEntity:withFormatName:)];
@@ -187,7 +189,7 @@ - (BOOL)_retrieveImageForEntity:(id <FICEntity>)entity withFormatName:(NSString
             }
         };
         
-        if (image == nil && _delegate != nil) {
+        if (image == nil) {
             // No image for this UUID exists in the image table. We'll need to ask the delegate to retrieve the source asset.
             NSURL *sourceImageURL = [entity sourceImageURLWithFormatName:formatName];
             
@@ -200,9 +202,19 @@ - (BOOL)_retrieveImageForEntity:(id <FICEntity>)entity withFormatName:(NSString
                     [_requests setObject:requestDictionary forKey:sourceImageURL];
                     
                     _FICAddCompletionBlockForEntity(formatName, requestDictionary, entity, completionBlock);
-                    [_delegate imageCache:self wantsSourceImageForEntity:entity withFormatName:formatName completionBlock:^(UIImage *sourceImage) {
+                    UIImage *image;
+                    if ([entity respondsToSelector:@selector(imageForFormat:)]){
+                        FICImageFormat *format = [self formatWithName:formatName];
+                        image = [entity imageForFormat:format];
+                    }
+                    
+                    if (image){
+                        [self _imageDidLoad:image forURL:sourceImageURL];
+                    } else if (_delegateImplementsWantsSourceImageForEntityWithFormatNameCompletionBlock){
+                        [_delegate imageCache:self wantsSourceImageForEntity:entity withFormatName:formatName completionBlock:^(UIImage *sourceImage) {
                         [self _imageDidLoad:sourceImage forURL:sourceImageURL];
-                    }];
+                        }];
+                    }
                 } else {
                     // We have an existing request dictionary, which means this URL is currently being fetched.
                     _FICAddCompletionBlockForEntity(formatName, requestDictionary, entity, completionBlock);

From a088781d34c777bda8b8ce8f806687d37474afc6 Mon Sep 17 00:00:00 2001
From: CHEN Xian'an <xianan.chen@gmail.com>
Date: Sat, 3 May 2014 22:47:45 +0800
Subject: [PATCH 2/2] oops! optional protocals should be marked using @optional
 exactly

---
 FastImageCache/FICImageCache.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/FastImageCache/FICImageCache.h b/FastImageCache/FICImageCache.h
index 8b88405..f59064a 100644
--- a/FastImageCache/FICImageCache.h
+++ b/FastImageCache/FICImageCache.h
@@ -227,6 +227,8 @@ typedef void (^FICImageRequestCompletionBlock)(UIImage *sourceImage);
  */
 @protocol FICImageCacheDelegate <NSObject>
 
+@optional
+
 /**
  This method is called on the delegate when the image cache needs a source image.