[Android NTP] Move suggestions in SuggestionSection into a separate TreeNode.

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SuggestionsSection.java

 // 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.
 
 package org.chromium.chrome.browser.ntp.cards;
 
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.ntp.snippets.CategoryInt;
 import org.chromium.chrome.browser.ntp.snippets.CategoryStatus.CategoryStatusEnum;
 import org.chromium.chrome.browser.ntp.snippets.SectionHeader;
 import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
+import org.chromium.chrome.browser.ntp.snippets.SnippetArticleViewHolder;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsBridge;
 
 import java.util.ArrayList;
 import java.util.List;
 
 /**
  * A group of suggestions, with a header, a status card, and a progress indicator.
  */
 public class SuggestionsSection extends InnerNode {
     private final List<TreeNode> mChildren = new ArrayList<>();
     private final List<SnippetArticle> mSuggestions = new ArrayList<>();
     private final SectionHeader mHeader;
+    private final TreeNode mSuggestionsList = new SuggestionsList(this);
     private final StatusItem mStatus;
     private final ProgressItem mProgressIndicator = new ProgressItem();
     private final ActionItem mMoreButton;
     private final SuggestionsCategoryInfo mCategoryInfo;
 
     public SuggestionsSection(NodeParent parent, SuggestionsCategoryInfo info) {
         super(parent);
         mHeader = new SectionHeader(info.getTitle());
         mCategoryInfo = info;
         mMoreButton = new ActionItem(info);
         mStatus = StatusItem.createNoSuggestionsItem(info);
         resetChildren();
     }
 
+    private class SuggestionsList extends ChildNode {
+        public SuggestionsList(NodeParent parent) {
+            super(parent);
+        }
+
+        @Override
+        public int getItemCount() {
+            return mSuggestions.size();
+        }
+
+        @Override
+        @ItemViewType
+        public int getItemViewType(int position) {
+            return ItemViewType.SNIPPET;
+        }
+
+        @Override
+        public void onBindViewHolder(NewTabPageViewHolder holder, int position) {
+            assert holder instanceof SnippetArticleViewHolder;
+            ((SnippetArticleViewHolder) holder).onBindViewHolder(getSuggestionAt(position));
+        }
+
+        @Override
+        public SnippetArticle getSuggestionAt(int position) {
+            return mSuggestions.get(position);
+        }
+
+        @Override
+        public int getDismissSiblingPosDelta(int position) {
+            return 0;
+        }
+    }
+
     @Override
     protected List<TreeNode> getChildren() {
         return mChildren;
     }
 
     private void resetChildren() {
         mChildren.clear();
         mChildren.add(mHeader);
-        mChildren.addAll(mSuggestions);
+        mChildren.add(mSuggestionsList);
 
         if (mSuggestions.isEmpty()) mChildren.add(mStatus);
         if (mCategoryInfo.hasMoreButton() || mSuggestions.isEmpty()) mChildren.add(mMoreButton);
         if (mSuggestions.isEmpty()) mChildren.add(mProgressIndicator);
     }
 
     public void removeSuggestion(SnippetArticle suggestion) {
         int removedIndex = mSuggestions.indexOf(suggestion);
         if (removedIndex == -1) return;
 
@@ skipping 125 matching lines @@
     @VisibleForTesting
     ActionItem getActionItem() {
         return mMoreButton;
     }
 
     @VisibleForTesting
     StatusItem getStatusItem() {
         return mStatus;
     }
 }