Content Indexing : Show NTP Card only when content available

We should show NTP entry point only when
1 - There are prefetch or content indexed articles available
2 - Show only once per session. If user dismissed in one tab, don't show it on another new tab when opened

Bug: 1031796
Change-Id: I229fa4ecfa1b58ffcfe281af5c732f168268ed36
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1956162
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#723625}

chrome/android/chrome_java_sources.gni

@@ -516,6 +516,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/download/DownloadUmaStatsEntry.java",
   "java/src/org/chromium/chrome/browser/download/DownloadUpdate.java",
   "java/src/org/chromium/chrome/browser/download/DownloadUtils.java",
+  "java/src/org/chromium/chrome/browser/download/ExploreOfflineStatusProvider.java",
   "java/src/org/chromium/chrome/browser/download/OMADownloadHandler.java",
   "java/src/org/chromium/chrome/browser/download/SystemDownloadNotifier.java",
   "java/src/org/chromium/chrome/browser/download/home/DownloadManagerCoordinator.java",

chrome/android/java/res/layout/new_tab_page_offline_card.xml

@@ -10,7 +10,10 @@
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:background="@drawable/hairline_border_card_background"
-    android:padding="@dimen/card_padding">
+    android:paddingTop="@dimen/card_padding"
+    android:paddingStart="@dimen/card_padding"
+    android:paddingEnd="@dimen/card_padding"
+    android:paddingBottom="10dp">
 
     <org.chromium.ui.widget.ChromeImageView
         android:id="@+id/icon"

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java

@@ -73,7 +73,6 @@ import org.chromium.components.offline_items_collection.OfflineItemState;
 import org.chromium.components.offline_items_collection.PendingState;
 import org.chromium.content_public.browser.BrowserStartupController;
 import org.chromium.content_public.browser.LoadUrlParams;
-import org.chromium.net.NetworkChangeNotifier;
 import org.chromium.ui.base.DeviceFormFactor;
 import org.chromium.ui.widget.Toast;
 
@@ -216,14 +215,6 @@ public class DownloadUtils {
         return true;
     }
 
-    /**
-     * @return Whether Chrome is currently offline and Offline Home should be shown for downloads.
-     */
-    public static boolean shouldShowOfflineHome() {
-        return ChromeFeatureList.isEnabled(ChromeFeatureList.OFFLINE_HOME)
-                && NetworkChangeNotifier.isInitialized() && !NetworkChangeNotifier.isOnline();
-    }
-
     /**
      * @return Whether or not the Intent corresponds to a DownloadActivity that should show off the
      *         record downloads.

chrome/android/java/src/org/chromium/chrome/browser/download/ExploreOfflineStatusProvider.java

+// Copyright 2019 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.download;
+
+import org.chromium.chrome.browser.download.items.OfflineContentAggregatorFactory;
+import org.chromium.chrome.browser.preferences.ChromePreferenceKeys;
+import org.chromium.chrome.browser.preferences.SharedPreferencesManager;
+import org.chromium.components.offline_items_collection.ContentId;
+import org.chromium.components.offline_items_collection.OfflineContentProvider;
+import org.chromium.components.offline_items_collection.OfflineItem;
+import org.chromium.components.offline_items_collection.UpdateDelta;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Keeps track of prefetch content addition and removal from chrome. This information is used to
+ * decide whether or not users should be see a message on NTP about offline content availability in
+ * chrome.
+ */
+public class ExploreOfflineStatusProvider implements OfflineContentProvider.Observer {
+    private static ExploreOfflineStatusProvider sInstance;
+
+    private Set<ContentId> mPrefetchItems = new HashSet<>();
+
+    /**
+     * @return An {@link ExploreOfflineStatusProvider} instance singleton.  If one
+     *         is not available this will create a new one.
+     */
+    public static ExploreOfflineStatusProvider getInstance() {
+        if (sInstance == null) {
+            sInstance = new ExploreOfflineStatusProvider();
+        }
+        return sInstance;
+    }
+
+    private ExploreOfflineStatusProvider() {
+        OfflineContentProvider provider = OfflineContentAggregatorFactory.get();
+        provider.addObserver(this);
+        provider.getAllItems(this::onItemsAdded);
+    }
+
+    /**
+     * @return Whether or not there are any prefetch content available in chrome.
+     */
+    public boolean isPrefetchContentAvailable() {
+        return SharedPreferencesManager.getInstance().readBoolean(
+                ChromePreferenceKeys.EXPLORE_OFFLINE_CONTENT_AVAILABILITY_STATUS, false);
+    }
+
+    @Override
+    public void onItemsAdded(ArrayList<OfflineItem> items) {
+        if (items.isEmpty()) return;
+
+        for (OfflineItem item : items) {
+            if (item.isSuggested) mPrefetchItems.add(item.id);
+        }
+        updateSharedPref();
+    }
+
+    @Override
+    public void onItemRemoved(ContentId id) {
+        if (mPrefetchItems.isEmpty()) return;
+
+        mPrefetchItems.remove(id);
+        updateSharedPref();
+    }
+
+    @Override
+    public void onItemUpdated(OfflineItem item, UpdateDelta updateDelta) {}
+
+    private void updateSharedPref() {
+        SharedPreferencesManager.getInstance().writeBoolean(
+                ChromePreferenceKeys.EXPLORE_OFFLINE_CONTENT_AVAILABILITY_STATUS,
+                !mPrefetchItems.isEmpty());
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/init/ProcessInitializationHandler.java

@@ -49,6 +49,7 @@ import org.chromium.chrome.browser.crash.LogcatExtractionRunnable;
 import org.chromium.chrome.browser.crash.MinidumpUploadService;
 import org.chromium.chrome.browser.download.DownloadController;
 import org.chromium.chrome.browser.download.DownloadManagerService;
+import org.chromium.chrome.browser.download.ExploreOfflineStatusProvider;
 import org.chromium.chrome.browser.firstrun.ForcedSigninProcessor;
 import org.chromium.chrome.browser.flags.FeatureUtilities;
 import org.chromium.chrome.browser.history.HistoryDeletionBridge;
@@ -444,6 +445,7 @@ public class ProcessInitializationHandler {
 
         deferredStartupHandler.addDeferredTask(
                 () -> SharedClipboardShareActivity.updateComponentEnabledState());
+        deferredStartupHandler.addDeferredTask(() -> ExploreOfflineStatusProvider.getInstance());
     }
 
     private void initChannelsAsync() {

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageLayout.java

@@ -889,7 +889,7 @@ public class NewTabPageLayout extends LinearLayout implements TileGroup.Observer
     private Runnable openDownloadHomeCallback() {
         return () -> {
             DownloadUtils.showDownloadManager(mActivity, mActivity.getActivityTabProvider().get(),
-                    DownloadOpenSource.NEW_TAB_PAGE);
+                    DownloadOpenSource.NEW_TAB_PAGE, true /*showPrefetchedContent*/);
         };
     }
 

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

@@ -10,7 +10,7 @@ import android.widget.Button;
 
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeFeatureList;
-import org.chromium.chrome.browser.download.DownloadUtils;
+import org.chromium.chrome.browser.download.ExploreOfflineStatusProvider;
 import org.chromium.net.NetworkChangeNotifier;
 
 /**
@@ -18,10 +18,10 @@ import org.chromium.net.NetworkChangeNotifier;
  * responsible for inflating the card layout and displaying the card based on network connectivity.
  */
 public class ExploreOfflineCard {
+    private static boolean sCardDismissed;
     private final View mRootView;
     private final Runnable mOpenDownloadHomeCallback;
     private NetworkChangeNotifier.ConnectionTypeObserver mConnectionTypeObserver;
-    private boolean mCardDismissed;
 
     /**
      * Constructor.
@@ -32,7 +32,7 @@ public class ExploreOfflineCard {
         mRootView = rootView;
         mOpenDownloadHomeCallback = openDownloadHomeCallback;
 
-        if (!ChromeFeatureList.isEnabled(ChromeFeatureList.OFFLINE_HOME)) return;
+        if (!isFeatureEnabled()) return;
         setCardViewVisibility();
         mConnectionTypeObserver = connectionType -> {
             setCardViewVisibility();
@@ -47,7 +47,7 @@ public class ExploreOfflineCard {
     }
 
     private void setCardViewVisibility() {
-        boolean isVisible = !mCardDismissed && DownloadUtils.shouldShowOfflineHome();
+        boolean isVisible = !sCardDismissed && shouldShowExploreOfflineMessage();
         View cardView = mRootView.findViewById(R.id.explore_offline_card);
 
         if (cardView == null) {
@@ -64,14 +64,24 @@ public class ExploreOfflineCard {
         Button cancelButton = cardView.findViewById(R.id.button_secondary);
 
         confirmButton.setOnClickListener(v -> {
-            mCardDismissed = true;
+            sCardDismissed = true;
             setCardViewVisibility();
             mOpenDownloadHomeCallback.run();
         });
         cancelButton.setOnClickListener(v -> {
-            mCardDismissed = true;
+            sCardDismissed = true;
             setCardViewVisibility();
         });
         return cardView;
     }
+
+    private static boolean shouldShowExploreOfflineMessage() {
+        return isFeatureEnabled() && NetworkChangeNotifier.isInitialized()
+                && !NetworkChangeNotifier.isOnline()
+                && ExploreOfflineStatusProvider.getInstance().isPrefetchContentAvailable();
+    }
+
+    private static boolean isFeatureEnabled() {
+        return ChromeFeatureList.isEnabled(ChromeFeatureList.OFFLINE_HOME);
+    }
 }

chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceKeys.java

@@ -140,6 +140,12 @@ public final class ChromePreferenceKeys {
     public static final String CONTEXTUAL_SEARCH_IMPRESSIONS_WEEK_4 =
             "contextual_search_impressions_week_4";
 
+    /**
+     * Indicates whether or not there are prefetched content in chrome that can be viewed offline.
+     */
+    public static final String EXPLORE_OFFLINE_CONTENT_AVAILABILITY_STATUS =
+            "Chrome.NTPExploreOfflineCard.HasExploreOfflineContent";
+
     /**
      * Whether the promotion for data reduction has been skipped on first invocation.
      * Default value is false.
@@ -424,6 +430,7 @@ public final class ChromePreferenceKeys {
                 CONTEXTUAL_SEARCH_IMPRESSIONS_WEEK_2,
                 CONTEXTUAL_SEARCH_IMPRESSIONS_WEEK_3,
                 CONTEXTUAL_SEARCH_IMPRESSIONS_WEEK_4,
+                EXPLORE_OFFLINE_CONTENT_AVAILABILITY_STATUS,
                 PROMOS_SKIPPED_ON_FIRST_START,
                 SIGNIN_PROMO_LAST_SHOWN_MAJOR_VERSION,
                 SIGNIN_PROMO_LAST_SHOWN_ACCOUNT_NAMES,