Fetch images for ContentSuggestions

ios/chrome/browser/content_suggestions/content_suggestions_mediator.mm

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/chrome/browser/content_suggestions/content_suggestions_mediator.h"
 
 #include "base/mac/bind_objc_block.h"
 #include "base/memory/ptr_util.h"
 #include "base/optional.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/ntp_snippets/category.h"
 #include "components/ntp_snippets/content_suggestion.h"
 #import "ios/chrome/browser/content_suggestions/content_suggestions_category_wrapper.h"
 #import "ios/chrome/browser/content_suggestions/content_suggestions_service_bridge_observer.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestion.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestion_id.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_data_sink.h"
+#import "ios/chrome/browser/ui/content_suggestions/content_suggestions_image_fetcher.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_item.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_section_information.h"
 #include "ui/gfx/image/image.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 
@@ skipping 48 matching lines @@
     sectionInfo.layout = SectionLayoutForLayout(categoryInfo->card_layout());
     if (categoryInfo->show_if_empty()) {
       // TODO(crbug.com/686728): Creates an item to display information when the
       // section is empty.
     }
     sectionInfo.title = base::SysUTF16ToNSString(categoryInfo->title());
   }
   return sectionInfo;
 }
 
+// Returns a ntp_snippets::ID based on a Objective-C Category and the ID in the
+// category.
+ntp_snippets::ContentSuggestion::ID SuggestionIDForSectionID(

[marq (ping after 24h), 2017/02/21 11:27:08]

Should this be a method on ContentSuggestionsCategoryWrapper?

[gambard, 2017/02/21 15:07:53]

Maybe. As they are only used in this file, I am not sure at the moment, and this
is why there are implemented as C function. If I need to move them around it
would be very easy.

+    ContentSuggestionsCategoryWrapper* category,
+    const std::string& id_in_category) {
+  return ntp_snippets::ContentSuggestion::ID(category.category, id_in_category);
+}
+
 }  // namespace
 
-@interface ContentSuggestionsMediator ()<ContentSuggestionsServiceObserver> {
+@interface ContentSuggestionsMediator ()<ContentSuggestionsImageFetcher,
+                                         ContentSuggestionsServiceObserver> {
   // Bridge for this class to become an observer of a ContentSuggestionsService.
   std::unique_ptr<ContentSuggestionsServiceBridge> _suggestionBridge;
 }
 
 @property(nonatomic, assign)
     ntp_snippets::ContentSuggestionsService* contentService;
 @property(nonatomic, strong, nonnull)
     NSMutableDictionary<ContentSuggestionsCategoryWrapper*,
                         ContentSuggestionsSectionInformation*>*
         sectionInformationByCategory;
 
 // Converts the data in |category| to ContentSuggestion and adds them to the
 // |contentArray|.
 - (void)addContentInCategory:(ntp_snippets::Category&)category
                      toArray:(NSMutableArray<ContentSuggestion*>*)contentArray;
 
 // Adds the section information for |category| in
 // self.sectionInformationByCategory.
 - (void)addSectionInformationForCategory:(ntp_snippets::Category)category;
 
+// Returns a CategoryWrapper acting as a key for this section info.
+- (ContentSuggestionsCategoryWrapper*)categoryWrapperForSectionInfo:
+    (ContentSuggestionsSectionInformation*)sectionInfo;
+
 @end
 
 @implementation ContentSuggestionsMediator
 
 @synthesize contentService = _contentService;
 @synthesize dataSink = _dataSink;
 @synthesize sectionInformationByCategory = _sectionInformationByCategory;
 
 - (instancetype)initWithContentService:
     (ntp_snippets::ContentSuggestionsService*)contentService {
@@ skipping 20 matching lines @@
     }
     if (!self.sectionInformationByCategory[
             [ContentSuggestionsCategoryWrapper wrapperWithCategory:category]]) {
       [self addSectionInformationForCategory:category];
     }
     [self addContentInCategory:category toArray:dataHolders];
   }
   return dataHolders;
 }
 
+- (id<ContentSuggestionsImageFetcher>)imageFetcher {
+  return self;
+}
+
 #pragma mark - ContentSuggestionsServiceObserver
 
 - (void)contentSuggestionsService:
             (ntp_snippets::ContentSuggestionsService*)suggestionsService
          newSuggestionsInCategory:(ntp_snippets::Category)category {
   [self.dataSink dataAvailable];
 }
 
 - (void)contentSuggestionsService:
             (ntp_snippets::ContentSuggestionsService*)suggestionsService
@@ skipping 12 matching lines @@
 - (void)contentSuggestionsServiceFullRefreshRequired:
     (ntp_snippets::ContentSuggestionsService*)suggestionsService {
   // Update dataSink.
 }
 
 - (void)contentSuggestionsServiceShutdown:
     (ntp_snippets::ContentSuggestionsService*)suggestionsService {
   // Update dataSink.
 }
 
+#pragma mark - ContentSuggestionsImageFetcher
+
+- (void)fetchImageForSuggestion:(ContentSuggestionID*)suggestionID
+                       callback:(void (^)(const gfx::Image&))callback {
+  self.contentService->FetchSuggestionImage(
+      SuggestionIDForSectionID(
+          [self categoryWrapperForSectionInfo:suggestionID.sectionInfo],
+          suggestionID.IDInSection),
+      base::BindBlockArc(callback));
+}
+
 #pragma mark - Private
 
 - (void)addContentInCategory:(ntp_snippets::Category&)category
                      toArray:(NSMutableArray<ContentSuggestion*>*)contentArray {
   const std::vector<ntp_snippets::ContentSuggestion>& suggestions =
       self.contentService->GetSuggestionsForCategory(category);
   ContentSuggestionsCategoryWrapper* categoryWrapper =
       [[ContentSuggestionsCategoryWrapper alloc] initWithCategory:category];
   for (auto& contentSuggestion : suggestions) {
     ContentSuggestion* suggestion = ConvertContentSuggestion(contentSuggestion);
     suggestion.type = TypeForCategory(category);
     suggestion.suggestionID.sectionInfo =
         self.sectionInformationByCategory[categoryWrapper];
 
-    // TODO(crbug.com/686728): fetch the image.
-
     [contentArray addObject:suggestion];
   }
 }
 
 - (void)addSectionInformationForCategory:(ntp_snippets::Category)category {
   base::Optional<ntp_snippets::CategoryInfo> categoryInfo =
       self.contentService->GetCategoryInfo(category);
 
   ContentSuggestionsSectionInformation* sectionInfo =
       SectionInformationFromCategoryInfo(categoryInfo, category);
 
   self.sectionInformationByCategory[[ContentSuggestionsCategoryWrapper
       wrapperWithCategory:category]] = sectionInfo;
 }
 
+- (ContentSuggestionsCategoryWrapper*)categoryWrapperForSectionInfo:
+    (ContentSuggestionsSectionInformation*)sectionInfo {
+  return [[self.sectionInformationByCategory allKeysForObject:sectionInfo]
+      firstObject];
+}
+
 @end