📰 Tweak the suggestion ranks for UMA to handle fetchMore

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SectionList.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.Log;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.ntp.NewTabPageView.NewTabPageManager;
 import org.chromium.chrome.browser.ntp.snippets.CategoryInt;
 import org.chromium.chrome.browser.ntp.snippets.CategoryStatus;
 import org.chromium.chrome.browser.ntp.snippets.CategoryStatus.CategoryStatusEnum;
 import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsBridge;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsConfig;
 import org.chromium.chrome.browser.ntp.snippets.SuggestionsSource;
 import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
+import org.chromium.chrome.browser.suggestions.SuggestionsRanker;
 
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
 /**
  * A node in the tree containing a list of all suggestions sections. It listens to changes in the
  * suggestions source and updates the corresponding sections.
  */
 public class SectionList
         extends InnerNode implements SuggestionsSource.Observer, SuggestionsSection.Delegate {
     private static final String TAG = "Ntp";
 
     /** Maps suggestion categories to sections, with stable iteration ordering. */
     private final Map<Integer, SuggestionsSection> mSections = new LinkedHashMap<>();
     private final NewTabPageManager mNewTabPageManager;
     private final OfflinePageBridge mOfflinePageBridge;
+    private final SuggestionsRanker mSuggestionsRanker;
 
     public SectionList(NewTabPageManager newTabPageManager, OfflinePageBridge offlinePageBridge) {
+        mSuggestionsRanker = new SuggestionsRanker();
         mNewTabPageManager = newTabPageManager;
         mNewTabPageManager.getSuggestionsSource().setObserver(this);
+        mNewTabPageManager.getSuggestionsMetricsReporter().setRanker(mSuggestionsRanker);
         mOfflinePageBridge = offlinePageBridge;
         resetSections(/* alwaysAllowEmptySections = */ false);
     }
 
     /**
      * Resets the sections, reloading the whole new tab page content.
      * @param alwaysAllowEmptySections Whether sections are always allowed to be displayed when
      *     they are empty, even when they are normally not.
      */
     public void resetSections(boolean alwaysAllowEmptySections) {
         removeAllSections();
 
         SuggestionsSource suggestionsSource = mNewTabPageManager.getSuggestionsSource();
         int[] categories = suggestionsSource.getCategories();
         int[] suggestionsPerCategory = new int[categories.length];
         int categoryIndex = 0;
         for (int category : categories) {
             int categoryStatus = suggestionsSource.getCategoryStatus(category);
             if (categoryStatus == CategoryStatus.LOADING_ERROR
                     || categoryStatus == CategoryStatus.NOT_PROVIDED
                     || categoryStatus == CategoryStatus.CATEGORY_EXPLICITLY_DISABLED)
                 continue;
 
             suggestionsPerCategory[categoryIndex] =
                     resetSection(category, categoryStatus, alwaysAllowEmptySections);
-            SuggestionsSection section = mSections.get(category);
-            if (section != null) section.setCategoryIndex(categoryIndex);
             ++categoryIndex;
         }
 
-        mNewTabPageManager.trackSnippetsPageImpression(categories, suggestionsPerCategory);
+        mNewTabPageManager.getSuggestionsMetricsReporter().onPageShown(
+                categories, suggestionsPerCategory);
     }
 
     /**
      * Resets the section for {@code category}. Removes the section if there are no suggestions for
      * it and it is not allowed to be empty. Otherwise, creates the section if it is not present
      * yet. Sets the available suggestions on the section.
      * @param category The category for which the section must be reset.
      * @param categoryStatus The category status.
      * @param alwaysAllowEmptySections Whether sections are always allowed to be displayed when
      *     they are empty, even when they are normally not.
      * @return The number of suggestions for the section.
      */
     private int resetSection(@CategoryInt int category, @CategoryStatusEnum int categoryStatus,
             boolean alwaysAllowEmptySections) {
         SuggestionsSource suggestionsSource = mNewTabPageManager.getSuggestionsSource();
         List<SnippetArticle> suggestions = suggestionsSource.getSuggestionsForCategory(category);
         SuggestionsCategoryInfo info = suggestionsSource.getCategoryInfo(category);
 
         SuggestionsSection section = mSections.get(category);
 
         // Do not show an empty section if not allowed.
         if (suggestions.isEmpty() && !info.showIfEmpty() && !alwaysAllowEmptySections) {
             if (section != null) removeSection(section);
             return 0;
         }
 
         // Create the section if needed.
         if (section == null) {
-            section = new SuggestionsSection(this, mNewTabPageManager, mOfflinePageBridge, info);
+            section = new SuggestionsSection(
+                    this, mNewTabPageManager, mSuggestionsRanker, mOfflinePageBridge, info);
             mSections.put(category, section);
+            mSuggestionsRanker.registerCategory(category);
             addChild(section);
         }
 
         // Set the new suggestions.
         setSuggestions(category, suggestions, categoryStatus, /* replaceExisting = */ true);
 
         return suggestions.size();
     }
 
     @Override
@@ skipping 69 matching lines @@
      * may have no or only partial effect if changing the list of suggestions is not allowed (e.g.
      * because the user has already seen the suggestions).
      * @param category The category for which the suggestions should be set.
      * @param suggestions The new list of suggestions for the given category.
      * @param status The new category status.
      * @param replaceExisting If true, {@code suggestions} replace the current list of suggestions.
      * If false, {@code suggestions} are appended to current list of suggestions.
      */
     private void setSuggestions(@CategoryInt int category, List<SnippetArticle> suggestions,
             @CategoryStatusEnum int status, boolean replaceExisting) {
-        // Count the number of suggestions before this category.
-        int globalPositionOffset = 0;
-        for (Map.Entry<Integer, SuggestionsSection> entry : mSections.entrySet()) {
-            if (entry.getKey() == category) break;
-            globalPositionOffset += entry.getValue().getSuggestionsCount();
-        }
-        // Assign global indices to the new suggestions.
-        for (SnippetArticle suggestion : suggestions) {
-            suggestion.mGlobalPosition = globalPositionOffset + suggestion.mPosition;
-        }
-
         mSections.get(category).setSuggestions(suggestions, status, replaceExisting);
     }
 
     private boolean canLoadSuggestions(@CategoryInt int category, @CategoryStatusEnum int status) {
         // We never want to add suggestions from unknown categories.
         if (!mSections.containsKey(category)) return false;
 
         // The status may have changed while the suggestions were loading, perhaps they should not
         // be displayed any more.
         if (!SnippetsBridge.isCategoryEnabled(status)) {
@@ skipping 41 matching lines @@
      * @return Whether the list of sections is empty.
      */
     public boolean isEmpty() {
         return mSections.isEmpty();
     }
 
     SuggestionsSection getSectionForTesting(@CategoryInt int categoryId) {
         return mSections.get(categoryId);
     }
 }