Suggestions UI - Add Data Source and Item

ios/chrome/browser/ui/suggestions/suggestions_collection_updater.mm

+// Copyright 2016 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/ui/suggestions/suggestions_collection_updater.h"
+
+#import "ios/chrome/browser/ui/collection_view/collection_view_controller.h"
+#import "ios/chrome/browser/ui/collection_view/collection_view_model.h"
+#import "ios/chrome/browser/ui/suggestions/suggestions_item.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+typedef NS_ENUM(NSInteger, ItemType) {
+  ItemTypeText = kItemTypeEnumZero,
+  ItemTypeArticle,
+  ItemTypeExpand,
+};
+
+}  // namespace
+
+@implementation SuggestionsCollectionUpdater {
+  CollectionViewController* _collectionViewController;
+}
+
+- (instancetype)initWithCollectionViewController:
+    (CollectionViewController*)collectionViewController {
+  self = [super init];
+  if (self) {
+    _collectionViewController = collectionViewController;
+    [collectionViewController loadModel];
+    CollectionViewModel* model = collectionViewController.collectionViewModel;
+    NSInteger sectionIdentifier = kSectionIdentifierEnumZero;
+    for (NSInteger i = 0; i < 3; i++) {
+      [model addSectionWithIdentifier:sectionIdentifier];
+      [model addItem:[[SuggestionsItem alloc] initWithType:ItemTypeText
+                                                     title:@"The title"
+                                                  subtitle:@"The subtitle"]
+          toSectionWithIdentifier:sectionIdentifier];
+      sectionIdentifier++;
+    }
+  }
+  return self;
+}
+
+#pragma mark - Public methods
+
+- (void)addTextItem:(NSString*)title
+           subtitle:(NSString*)subtitle
+          toSection:(NSInteger)inputSection {
+  SuggestionsItem* item = [[SuggestionsItem alloc] initWithType:ItemTypeText
+                                                          title:title
+                                                       subtitle:subtitle];
+  NSInteger sectionIdentifier = kSectionIdentifierEnumZero + inputSection;
+  NSInteger sectionIndex = inputSection;
+  CollectionViewModel* model = _collectionViewController.collectionViewModel;
+  if ([model numberOfSections] <= inputSection) {
+    sectionIndex = [model numberOfSections];
+    sectionIdentifier = kSectionIdentifierEnumZero + sectionIndex;
+    [_collectionViewController.collectionView performBatchUpdates:^{
+      [_collectionViewController.collectionViewModel
+          addSectionWithIdentifier:sectionIdentifier];
+      [_collectionViewController.collectionView
+          insertSections:[NSIndexSet indexSetWithIndex:sectionIndex]];
+    }
+                                                       completion:nil];
+  }
+  NSInteger numberOfItemsInSection =
+      [model numberOfItemsInSection:sectionIndex];
+  [_collectionViewController.collectionViewModel addItem:item
+                                 toSectionWithIdentifier:sectionIdentifier];
+  [_collectionViewController.collectionView performBatchUpdates:^{
+    [_collectionViewController.collectionView
+        insertItemsAtIndexPaths:@[ [NSIndexPath
+                                    indexPathForRow:numberOfItemsInSection
+                                          inSection:sectionIndex] ]];
+  }
+                                                     completion:nil];
+}
+
+@end