📰 Tweak the suggestion ranks for UMA to handle fetchMore

chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java
index a9928ce1f0d291e994b5ab09cb51990abfc6bdc7..52b225c1c12de9b794e34e36fca082f23aaf809b 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java
@@ -8,9 +8,13 @@
 
 import org.chromium.base.Callback;
 import org.chromium.base.annotations.CalledByNative;
+import org.chromium.chrome.browser.ntp.NewTabPageUma;
+import org.chromium.chrome.browser.ntp.cards.ActionItem;
 import org.chromium.chrome.browser.ntp.cards.SuggestionsCategoryInfo;
 import org.chromium.chrome.browser.ntp.snippets.CategoryStatus.CategoryStatusEnum;
 import org.chromium.chrome.browser.profiles.Profile;
+import org.chromium.chrome.browser.suggestions.SuggestionsMetricsReporter;
+import org.chromium.chrome.browser.suggestions.SuggestionsRanker;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -18,11 +22,12 @@
 /**
  * Provides access to the snippets to display on the NTP using the C++ ContentSuggestionsService.
  */
-public class SnippetsBridge implements SuggestionsSource {
+public class SnippetsBridge implements SuggestionsSource, SuggestionsMetricsReporter {
     private static final String TAG = "SnippetsBridge";
 
     private long mNativeSnippetsBridge;
     private SuggestionsSource.Observer mObserver;
+    private SuggestionsRanker mSuggestionsRanker;
 
     public static boolean isCategoryStatusAvailable(@CategoryStatusEnum int status) {
         // Note: This code is duplicated in content_suggestions_category_status.cc.
@@ -119,8 +124,8 @@ public void fetchSuggestionImage(SnippetArticle suggestion, Callback<Bitmap> cal
     @Override
     public void dismissSuggestion(SnippetArticle suggestion) {
         assert mNativeSnippetsBridge != 0;
-        nativeDismissSuggestion(mNativeSnippetsBridge, suggestion.mUrl, suggestion.mGlobalPosition,
-                suggestion.mCategory, suggestion.mPosition, suggestion.mIdWithinCategory);
+        nativeDismissSuggestion(mNativeSnippetsBridge, suggestion.mUrl, suggestion.getGlobalRank(),
+                suggestion.mCategory, suggestion.getPerSectionRank(), suggestion.mIdWithinCategory);
     }
 
     @Override
@@ -135,41 +140,66 @@ public void restoreDismissedCategories() {
         nativeRestoreDismissedCategories(mNativeSnippetsBridge);
     }
 
+    @Override
     public void onPageShown(int[] categories, int[] suggestionsPerCategory) {
         assert mNativeSnippetsBridge != 0;
         nativeOnPageShown(mNativeSnippetsBridge, categories, suggestionsPerCategory);
     }
 
+    @Override
     public void onSuggestionShown(SnippetArticle suggestion) {
         assert mNativeSnippetsBridge != 0;
-        nativeOnSuggestionShown(mNativeSnippetsBridge, suggestion.mGlobalPosition,
-                suggestion.mCategory, suggestion.mPosition,
+        nativeOnSuggestionShown(mNativeSnippetsBridge, suggestion.getGlobalRank(),
+                suggestion.mCategory, suggestion.getPerSectionRank(),
                 suggestion.mPublishTimestampMilliseconds, suggestion.mScore);
     }
 
-    public void onSuggestionOpened(
-            SnippetArticle suggestion, int categoryIndex, int windowOpenDisposition) {
+    @Override
+    public void onSuggestionOpened(SnippetArticle suggestion, int windowOpenDisposition) {
         assert mNativeSnippetsBridge != 0;
-        nativeOnSuggestionOpened(mNativeSnippetsBridge, suggestion.mGlobalPosition,
-                suggestion.mCategory, categoryIndex, suggestion.mPosition,
+        int categoryIndex = mSuggestionsRanker.getCategoryRank(suggestion.mCategory);

[vitaliii, 2017/01/18 08:46:27]

Rank is expected to be 1-based.
E.g. https://en.wikipedia.org/wiki/Mean_reciprocal_rank .

[dgn, 2017/01/18 10:47:42]

Maybe, but "index" and "position" are both misleading as they are more or less
arbitrary values attributed to items here. I'd prefer to have the name be
inaccurate in that aspect rather than leading to confusion while trying to
manipulate actual indices of the items in the UI. The documentation for
SuggestionsRanker explicitly mentions that it uses rank as 0-based. 

I'm up for changing the name as long as it reflects the fact that the value is
not the actual position of the element, is not continuous, etc.

+        nativeOnSuggestionOpened(mNativeSnippetsBridge, suggestion.getGlobalRank(),
+                suggestion.mCategory, categoryIndex, suggestion.getPerSectionRank(),
                 suggestion.mPublishTimestampMilliseconds, suggestion.mScore, windowOpenDisposition);
     }
 
+    @Override
     public void onSuggestionMenuOpened(SnippetArticle suggestion) {
         assert mNativeSnippetsBridge != 0;
-        nativeOnSuggestionMenuOpened(mNativeSnippetsBridge, suggestion.mGlobalPosition,
-                suggestion.mCategory, suggestion.mPosition,
+        nativeOnSuggestionMenuOpened(mNativeSnippetsBridge, suggestion.getGlobalRank(),
+                suggestion.mCategory, suggestion.getPerSectionRank(),
                 suggestion.mPublishTimestampMilliseconds, suggestion.mScore);
     }
 
-    public void onMoreButtonShown(int category, int position) {
+    @Override
+    public void onMoreButtonShown(ActionItem actionItem) {
         assert mNativeSnippetsBridge != 0;
-        nativeOnMoreButtonShown(mNativeSnippetsBridge, category, position);
+        nativeOnMoreButtonShown(
+                mNativeSnippetsBridge, actionItem.getCategory(), actionItem.getPerSectionRank());
     }
 
-    public void onMoreButtonClicked(int category, int position) {
+    @Override
+    public void onMoreButtonClicked(ActionItem actionItem) {
         assert mNativeSnippetsBridge != 0;
-        nativeOnMoreButtonClicked(mNativeSnippetsBridge, category, position);
+        @CategoryInt
+        int category = actionItem.getCategory();
+        nativeOnMoreButtonClicked(mNativeSnippetsBridge, category, actionItem.getPerSectionRank());
+        switch (category) {
+            case KnownCategories.BOOKMARKS:
+                NewTabPageUma.recordAction(NewTabPageUma.ACTION_OPENED_BOOKMARKS_MANAGER);
+                break;
+            // MORE button in both categories leads to the recent tabs manager
+            case KnownCategories.FOREIGN_TABS:
+            case KnownCategories.RECENT_TABS:
+                NewTabPageUma.recordAction(NewTabPageUma.ACTION_OPENED_RECENT_TABS_MANAGER);
+                break;
+            case KnownCategories.DOWNLOADS:
+                NewTabPageUma.recordAction(NewTabPageUma.ACTION_OPENED_DOWNLOADS_MANAGER);
+                break;
+            default:
+                // No action associated
+                break;
+        }
     }
 
     /**
@@ -194,21 +224,19 @@ public static void onSuggestionTargetVisited(int category, long visitTimeMs) {
         nativeOnSuggestionTargetVisited(category, visitTimeMs);
     }
 
-    /**
-     * Sets the recipient for the fetched snippets.
-     *
-     * An observer needs to be set before the native code attempts to transmit snippets them to
-     * java. Upon registration, the observer will be notified of already fetched snippets.
-     *
-     * @param observer object to notify when snippets are received.
-     */
     @Override
-    public void setObserver(SuggestionsSource.Observer observer) {
+    public void setObserver(Observer observer) {
         assert observer != null;
         mObserver = observer;
     }
 
     @Override
+    public void setRanker(SuggestionsRanker suggestionsRanker) {
+        assert suggestionsRanker != null;
+        mSuggestionsRanker = suggestionsRanker;
+    }
+
+    @Override
     public void fetchSuggestions(@CategoryInt int category, String[] displayedSuggestionIds) {
         nativeFetch(mNativeSnippetsBridge, category, displayedSuggestionIds);
     }
@@ -234,7 +262,7 @@ private static SnippetArticle addSuggestion(List<SnippetArticle> suggestions, in
             long timestamp, float score) {
         int position = suggestions.size();
         suggestions.add(new SnippetArticle(
-                category, id, title, publisher, previewText, url, timestamp, score, position));
+                category, id, title, publisher, previewText, url, timestamp, score));
         return suggestions.get(position);
     }