Add CSDataSource in showcase

ios/showcase/content_suggestions/sc_content_suggestions_data_source.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/showcase/content_suggestions/sc_content_suggestions_data_source.h"
+
+#include "components/strings/grit/components_strings.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/identifier/content_suggestion_identifier.h"
+#import "ios/chrome/browser/ui/content_suggestions/identifier/content_suggestions_section_information.h"
+#import "ios/chrome/browser/ui/favicon/favicon_attributes.h"
+#include "ios/chrome/grit/ios_strings.h"
+#import "ios/showcase/content_suggestions/sc_content_suggestions_item.h"
+#import "ios/showcase/content_suggestions/sc_content_suggestions_most_visited_item.h"
+#include "ui/base/l10n/l10n_util_mac.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+using CSCollectionViewItem = CollectionViewItem<SuggestedContent>;
+}
+
+@interface SCContentSuggestionsDataSource ()<ContentSuggestionsImageFetcher>
+
+// Section Info of type MostVisited. Created lazily.
+@property(nonatomic, strong)
+    ContentSuggestionsSectionInformation* mostVisitedSection;
+// Section Info of type Reading List. Created lazily.
+@property(nonatomic, strong)
+    ContentSuggestionsSectionInformation* readingListSection;
+// Section Info of type Article. Created lazily.
+@property(nonatomic, strong)
+    ContentSuggestionsSectionInformation* articleSection;
+
+@end
+
+@implementation SCContentSuggestionsDataSource
+
+@synthesize dataSink = _dataSink;
+@synthesize mostVisitedSection = _mostVisitedSection;
+@synthesize readingListSection = _readingListSection;
+@synthesize articleSection = _articleSection;
+
+#pragma mark - ContentSuggestionsDataSource
+
+- (NSArray<ContentSuggestionsSectionInformation*>*)sectionsInfo {
+  return @[
+    self.mostVisitedSection, self.readingListSection, self.articleSection
+  ];
+}
+
+- (NSArray<CSCollectionViewItem*>*)itemsForSectionInfo:
+    (ContentSuggestionsSectionInformation*)sectionInfo {
+  switch (sectionInfo.sectionID) {
+    case ContentSuggestionsSectionMostVisited: {
+      NSMutableArray<CSCollectionViewItem*>* items = [NSMutableArray array];
+      for (int i = 0; i < 8; i++) {
+        SCContentSuggestionsMostVisitedItem* suggestion =
+            [[SCContentSuggestionsMostVisitedItem alloc] initWithType:0];
+        suggestion.title =
+            [NSString stringWithFormat:@"Test Tile number %i", i];
+        suggestion.attributes = [self randomColorFaviconAttributes];
+        [items addObject:suggestion];
+      }
+      return items;
+    }
+    case ContentSuggestionsSectionReadingList: {
+      SCContentSuggestionsItem* suggestion = [self article];
+      suggestion.title = @"Reading List item: No subtitle, no image";
+      suggestion.subtitle = nil;
+      suggestion.hasImage = NO;
+      suggestion.suggestionIdentifier.sectionInfo = self.readingListSection;
+      return @[ suggestion ];
+    }
+    case ContentSuggestionsSectionArticles: {
+      NSMutableArray<CSCollectionViewItem*>* items = [NSMutableArray array];
+      SCContentSuggestionsItem* suggestion = [self article];
+      suggestion.title = @"Title of the first suggestions";
+      suggestion.suggestionIdentifier.IDInSection = std::to_string(1);
+      [items addObject:suggestion];
+      for (int i = 2; i < 6; i++) {
+        suggestion = suggestion = [self article];
+        suggestion.title = [NSString
+            stringWithFormat:@"Title of the suggestions number #%i", i];
+        suggestion.suggestionIdentifier.IDInSection = std::to_string(i);
+        [items addObject:suggestion];
+      }
+      return items;
+    }
+    case ContentSuggestionsSectionUnknown:
+      return @[];
+  }
+}
+
+- (id<ContentSuggestionsImageFetcher>)imageFetcher {
+  return self;
+}
+
+- (void)fetchMoreSuggestionsKnowing:
+            (NSArray<ContentSuggestionIdentifier*>*)knownSuggestions
+                    fromSectionInfo:
+                        (ContentSuggestionsSectionInformation*)sectionInfo
+                           callback:(MoreSuggestionsFetched)callback {
+}
+
+- (void)fetchFaviconAttributesForItem:(CSCollectionViewItem*)item
+                           completion:(void (^)(FaviconAttributes*))completion {
+}
+
+- (void)fetchFaviconImageForItem:(CSCollectionViewItem*)item
+                      completion:(void (^)(UIImage*))completion {
+}
+
+#pragma mark - ContentSuggestionsImageFetcher
+
+- (void)fetchImageForSuggestion:
+            (ContentSuggestionIdentifier*)suggestionIdentifier
+                       callback:(void (^)(UIImage*))callback {
+  if (callback) {
+    callback([UIImage imageNamed:@"reading_list_empty_state"]);
+  }
+}
+
+#pragma mark - Property
+
+- (ContentSuggestionsSectionInformation*)mostVisitedSection {
+  if (!_mostVisitedSection) {
+    _mostVisitedSection = [[ContentSuggestionsSectionInformation alloc]
+        initWithSectionID:ContentSuggestionsSectionMostVisited];
+    _mostVisitedSection.layout = ContentSuggestionsSectionLayoutCustom;
+  }
+  return _mostVisitedSection;
+}
+
+- (ContentSuggestionsSectionInformation*)readingListSection {
+  if (!_readingListSection) {
+    _readingListSection = [[ContentSuggestionsSectionInformation alloc]
+        initWithSectionID:ContentSuggestionsSectionReadingList];
+    _readingListSection.title =
+        l10n_util::GetNSString(IDS_NTP_READING_LIST_SUGGESTIONS_SECTION_HEADER);
+    _readingListSection.footerTitle =
+        l10n_util::GetNSString(IDS_IOS_CONTENT_SUGGESTIONS_FOOTER_TITLE);
+  }
+  return _readingListSection;
+}
+
+- (ContentSuggestionsSectionInformation*)articleSection {
+  if (!_articleSection) {
+    _articleSection = [[ContentSuggestionsSectionInformation alloc]
+        initWithSectionID:ContentSuggestionsSectionArticles];
+    _articleSection.title =
+        l10n_util::GetNSString(IDS_NTP_ARTICLE_SUGGESTIONS_SECTION_HEADER);
+    _articleSection.footerTitle =
+        l10n_util::GetNSString(IDS_IOS_CONTENT_SUGGESTIONS_FOOTER_TITLE);
+  }
+  return _articleSection;
+}
+
+#pragma mark - Private
+
+// Returns a favicon attributes with a random background color and a random

[lpromero, 2017/05/22 13:01:50]

Nit: "Returns favicon attributes".

[gambard, 2017/06/02 14:46:04]

Done.

+// monogram.
+- (FaviconAttributes*)randomColorFaviconAttributes {
+  UIColor* backgroundColor = [[UIColor alloc] initWithHue:drand48()
+                                               saturation:drand48() / 2 + 0.5
+                                               brightness:drand48() / 2 + 0.5
+                                                    alpha:1.0];
+
+  NSString* monogram =
+      [NSString stringWithFormat:@"%c", arc4random_uniform(26) + 'A'];
+  UIColor* textColor =
+      drand48() > 0.5 ? [UIColor whiteColor] : [UIColor blackColor];
+
+  return [FaviconAttributes attributesWithMonogram:monogram
+                                         textColor:textColor
+                                   backgroundColor:backgroundColor];
+}
+
+// Returns a random date between now and three days before now.
+- (NSDate*)randomDate {
+  int offset = arc4random_uniform(259200);
+  return [NSDate dateWithTimeIntervalSinceNow:-offset];
+}
+
+// Returns and article with the fields set except the IDInSection.

[lpromero, 2017/05/22 13:01:50]

Nit: s/and/an

[gambard, 2017/06/02 14:46:04]

Done.

+- (SCContentSuggestionsItem*)article {
+  SCContentSuggestionsItem* suggestion =
+      [[SCContentSuggestionsItem alloc] initWithType:0];
+  suggestion.title = @"Title";
+  suggestion.subtitle = @"Subtitle for this greeeeeaaaaaat suggestion!";
+  suggestion.publisher = @"Publisher of the new";
+  suggestion.hasImage = YES;
+  suggestion.publishDate = [self randomDate];
+  suggestion.attributes = [self randomColorFaviconAttributes];
+  suggestion.suggestionIdentifier = [[ContentSuggestionIdentifier alloc] init];
+  suggestion.suggestionIdentifier.sectionInfo = self.articleSection;
+  return suggestion;
+}
+
+@end