Bug 1277467 - Add OfflineTabStatusDelegate for displaying tab-is-offline notifiations when appropriate r=sebastian

- Use Content:PageShow event to inform Tabs that they were actively loaded from cache
- Move offline notification logic away from browser.js and into a delegate, which displays notifications when
tab in question is user-visible

MozReview-Commit-ID: 2qCACHyWOlp

--HG--
extra : rebase_source : 457a42ebba5cfc32ab7dabce0a8a11d6511b9c08

mobile/android/base/java/org/mozilla/gecko/BrowserApp.java

@@ -24,6 +24,7 @@ import org.mozilla.gecko.db.BrowserContract;
 import org.mozilla.gecko.db.BrowserDB;
 import org.mozilla.gecko.db.SuggestedSites;
 import org.mozilla.gecko.delegates.BrowserAppDelegate;
+import org.mozilla.gecko.delegates.OfflineTabStatusDelegate;
 import org.mozilla.gecko.delegates.ScreenshotDelegate;
 import org.mozilla.gecko.distribution.Distribution;
 import org.mozilla.gecko.distribution.DistributionStoreCallback;
@@ -312,7 +313,8 @@ public class BrowserApp extends GeckoApp
             (BrowserAppDelegate) new ReaderViewBookmarkPromotion(),
             (BrowserAppDelegate) new ContentNotificationsDelegate(),
             (BrowserAppDelegate) new PostUpdateHandler(),
-            new TelemetryCorePingDelegate()
+            new TelemetryCorePingDelegate(),
+            new OfflineTabStatusDelegate()
     ));
 
     @NonNull

mobile/android/base/java/org/mozilla/gecko/Tab.java

@@ -104,6 +104,9 @@ public class Tab {
     private boolean mIsEditing;
     private final TabEditingState mEditingState = new TabEditingState();
 
+    // Will be true when tab is loaded from cache while device was offline.
+    private boolean mLoadedFromCache;
+
     public static final int STATE_DELAYED = 0;
     public static final int STATE_LOADING = 1;
     public static final int STATE_SUCCESS = 2;
@@ -301,6 +304,10 @@ public class Tab {
         return mHasOpenSearch;
     }
 
+    public boolean hasLoadedFromCache() {
+        return mLoadedFromCache;
+    }
+
     public SiteIdentity getSiteIdentity() {
         return mSiteIdentity;
     }
@@ -536,6 +543,10 @@ public class Tab {
         mHasOpenSearch = hasOpenSearch;
     }
 
+    public void setLoadedFromCache(boolean loadedFromCache) {
+        mLoadedFromCache = loadedFromCache;
+    }
+
     public void updateIdentityData(JSONObject identityData) {
         mSiteIdentity.update(identityData);
     }

mobile/android/base/java/org/mozilla/gecko/Tabs.java

@@ -105,6 +105,7 @@ public class Tabs implements GeckoEventListener {
             "Tab:Added",
             "Tab:Close",
             "Tab:Select",
+            "Tab:LoadedFromCache",
             "Content:LocationChange",
             "Content:SecurityChange",
             "Content:StateChange",
@@ -505,8 +506,9 @@ public class Tabs implements GeckoEventListener {
                 tab.handleContentLoaded();
                 notifyListeners(tab, Tabs.TabEvents.LOAD_ERROR);
             } else if (event.equals("Content:PageShow")) {
-                notifyListeners(tab, TabEvents.PAGE_SHOW);
+                tab.setLoadedFromCache(message.getBoolean("fromCache"));
                 tab.updateUserRequested(message.getString("userRequested"));
+                notifyListeners(tab, TabEvents.PAGE_SHOW);
             } else if (event.equals("DOMContentLoaded")) {
                 tab.handleContentLoaded();
                 String backgroundColor = message.getString("bgColor");

mobile/android/base/java/org/mozilla/gecko/TelemetryContract.java

@@ -104,6 +104,9 @@ public interface TelemetryContract {
         // Stop holding a resource (reader, bookmark, etc) for viewing later.
         UNSAVE("unsave.1"),
 
+        // When the user performs actions on the in-content network error page.
+        NETERROR("neterror.1"),
+
         // VALUES BELOW THIS LINE ARE EXCLUSIVE TO TESTING.
         _TEST1("_test_event_1.1"),
         _TEST2("_test_event_2.1"),

mobile/android/base/java/org/mozilla/gecko/delegates/OfflineTabStatusDelegate.java

@@ -0,0 +1,110 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.delegates;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.support.annotation.CallSuper;
+import android.support.design.widget.Snackbar;
+import android.support.v4.content.ContextCompat;
+
+import org.mozilla.gecko.AboutPages;
+import org.mozilla.gecko.BrowserApp;
+import org.mozilla.gecko.R;
+import org.mozilla.gecko.SnackbarHelper;
+import org.mozilla.gecko.Tab;
+import org.mozilla.gecko.Tabs;
+import org.mozilla.gecko.Telemetry;
+import org.mozilla.gecko.TelemetryContract;
+
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.WeakHashMap;
+
+/**
+ * Displays "Showing offline version" message when tabs are loaded from cache while offline.
+ */
+public class OfflineTabStatusDelegate extends TabsTrayVisibilityAwareDelegate implements Tabs.OnTabsChangedListener {
+    private WeakReference<Activity> activityReference;
+    private WeakHashMap<Tab, Void> tabsQueuedForOfflineSnackbar = new WeakHashMap<>();
+
+    @CallSuper
+    @Override
+    public void onCreate(BrowserApp browserApp, Bundle savedInstanceState) {
+        super.onCreate(browserApp, savedInstanceState);
+        activityReference = new WeakReference<Activity>(browserApp);
+    }
+
+    @Override
+    public void onResume(BrowserApp browserApp) {
+        Tabs.registerOnTabsChangedListener(this);
+    }
+
+    @Override
+    public void onPause(BrowserApp browserApp) {
+        Tabs.unregisterOnTabsChangedListener(this);
+    }
+
+    public void onTabChanged(final Tab tab, Tabs.TabEvents event, String data) {
+        if (tab == null) {
+            return;
+        }
+
+        // Ignore tabs loaded regularly.
+        if (!tab.hasLoadedFromCache()) {
+            return;
+        }
+
+        // Ignore tabs displaying about pages
+        if (AboutPages.isAboutPage(tab.getURL())) {
+            return;
+        }
+
+        switch (event) {
+            // Show offline notification if tab is visible, or queue it for display later.
+            case PAGE_SHOW:
+                if (!isTabsTrayVisible() && Tabs.getInstance().isSelectedTab(tab)) {
+                    showLoadedOfflineSnackbar(activityReference.get());
+                } else {
+                    tabsQueuedForOfflineSnackbar.put(tab, null);
+                }
+                break;
+            // When tab is selected and offline notification was queued, display it if possible.
+            // SELECTED event might also fire when we're on a TabStrip, so check first.
+            case SELECTED:
+                if (isTabsTrayVisible()) {
+                    break;
+                }
+                if (tabsQueuedForOfflineSnackbar.containsKey(tab)) {
+                    showLoadedOfflineSnackbar(activityReference.get());
+                    tabsQueuedForOfflineSnackbar.remove(tab);
+                }
+                break;
+        }
+    }
+
+    /**
+     * Displays the notification snackbar and logs a telemetry event.
+     *
+     * @param activity which will be used for displaying the snackbar.
+     */
+    private static void showLoadedOfflineSnackbar(final Activity activity) {
+        if (activity == null) {
+            return;
+        }
+
+        Telemetry.sendUIEvent(TelemetryContract.Event.NETERROR, TelemetryContract.Method.TOAST, "usecache");
+
+        SnackbarHelper.showSnackbarWithActionAndColors(
+                activity,
+                activity.getResources().getString(R.string.tab_offline_version),
+                Snackbar.LENGTH_INDEFINITE,
+                null, null, null,
+                ContextCompat.getColor(activity, R.color.link_blue),
+                null
+        );
+    }
+}

mobile/android/base/java/org/mozilla/gecko/promotion/AddToHomeScreenPromotion.java

@@ -9,6 +9,7 @@ import android.app.Activity;
 import android.content.Context;
 import android.database.Cursor;
 import android.os.Bundle;
+import android.support.annotation.CallSuper;
 import android.util.Log;
 
 import com.keepsafe.switchboard.SwitchBoard;
@@ -23,7 +24,7 @@ import org.mozilla.gecko.Tabs;
 import org.mozilla.gecko.db.BrowserContract;
 import org.mozilla.gecko.db.BrowserDB;
 import org.mozilla.gecko.db.UrlAnnotations;
-import org.mozilla.gecko.delegates.ForegroundAwareDelegate;
+import org.mozilla.gecko.delegates.TabsTrayVisibilityAwareDelegate;
 import org.mozilla.gecko.util.Experiments;
 import org.mozilla.gecko.util.ThreadUtils;
 
@@ -34,7 +35,7 @@ import ch.boye.httpclientandroidlib.util.TextUtils;
 /**
  * Promote "Add to home screen" if user visits website often.
  */
-public class AddToHomeScreenPromotion extends ForegroundAwareDelegate implements Tabs.OnTabsChangedListener {
+public class AddToHomeScreenPromotion extends TabsTrayVisibilityAwareDelegate implements Tabs.OnTabsChangedListener {
     private static class URLHistory {
         public final long visits;
         public final long lastVisit;
@@ -57,6 +58,7 @@ public class AddToHomeScreenPromotion extends ForegroundAwareDelegate implements
     private int lastVisitMinimumAgeMs;
     private int lastVisitMaximumAgeMs;
 
+    @CallSuper
     @Override
     public void onCreate(BrowserApp browserApp, Bundle savedInstanceState) {
         super.onCreate(browserApp, savedInstanceState);
@@ -127,7 +129,7 @@ public class AddToHomeScreenPromotion extends ForegroundAwareDelegate implements
             return;
         }
 
-        if (!isInForeground) {
+        if (isTabsTrayVisible()) {
             // We only want to show this prompt if this tab is in the foreground and not on top
             // of the tabs tray.
             return;

mobile/android/base/locales/en-US/android_strings.dtd

@@ -47,6 +47,9 @@
 
 <!ENTITY  switch_to_tab "Switch to tab">
 
+<!-- Localization note: Shown in a snackbar when tab is loaded from cache while device was offline. -->
+<!ENTITY  tab_offline_version "Showing offline version">
+
 <!ENTITY  crash_reporter_title "&brandShortName; Crash Reporter">
 <!ENTITY  crash_message2 "&brandShortName; had a problem and crashed. Your tabs should be listed on the &brandShortName; Start page when you restart.">
 <!ENTITY  crash_send_report_message3 "Tell &vendorShortName; about this crash so they can fix it">

mobile/android/base/moz.build

@@ -262,6 +262,7 @@ gbjar.sources += ['java/org/mozilla/gecko/' + x for x in [
     'delegates/BookmarkStateChangeDelegate.java',
     'delegates/BrowserAppDelegate.java',
     'delegates/BrowserAppDelegateWithReference.java',
+    'delegates/OfflineTabStatusDelegate.java',
     'delegates/ScreenshotDelegate.java',
     'delegates/TabsTrayVisibilityAwareDelegate.java',
     'DevToolsAuthHelper.java',

mobile/android/base/strings.xml.in

@@ -68,6 +68,8 @@
 
   <string name="switch_to_tab">&switch_to_tab;</string>
 
+  <string name="tab_offline_version">&tab_offline_version;</string>
+
   <string name="crash_reporter_title">&crash_reporter_title;</string>
   <string name="crash_message2">&crash_message2;</string>
   <string name="crash_send_report_message3">&crash_send_report_message3;</string>

mobile/android/chrome/content/browser.js

@@ -4297,7 +4297,8 @@ Tab.prototype = {
         Messaging.sendRequest({
           type: "Content:PageShow",
           tabID: this.id,
-          userRequested: this.userRequested
+          userRequested: this.userRequested,
+          fromCache: Tabs.useCache
         });
 
         this.isSearch = false;
@@ -7377,25 +7378,6 @@ var Tabs = {
         // Clear the domain cache whenever a page is loaded into any browser.
         this._domains.clear();
 
-        // Notify if we are loading a page from cache.
-        if (this._useCache) {
-          let targetDoc = aEvent.originalTarget;
-          let isTopLevel = (targetDoc.defaultView.parent === targetDoc.defaultView);
-
-          // Ignore any about: pages, especially about:neterror since it means we failed to find the page in cache.
-          let targetURI = targetDoc.documentURI;
-          if (isTopLevel && !targetURI.startsWith("about:")) {
-            UITelemetry.addEvent("neterror.1", "toast", null, "usecache");
-            Snackbars.show(
-              Strings.browser.GetStringFromName("networkOffline.message2"),
-              Snackbars.LENGTH_INDEFINITE,
-              {
-                // link_blue
-                backgroundColor: "#0096DD"
-              }
-            );
-          }
-        }
         break;
       case "TabOpen":
         // Use opening a new tab as a trigger to expire the most stale tab.

mobile/android/locales/en-US/chrome/browser.properties

@@ -434,9 +434,6 @@ openInApp.pageAction = Open in App
 openInApp.ok = OK
 openInApp.cancel = Cancel
 
-#Network Offline
-networkOffline.message2 = Showing offline version
-
 #Tab sharing
 tabshare.title = "Choose a tab to stream"
 #Tabs in context menus