Added watchdog

app/src/main/java/eu/faircode/email/ApplicationEx.java

@@ -120,6 +120,7 @@ public class ApplicationEx extends Application {
         MessageHelper.setSystemProperties();
         ContactInfo.init(this, new Handler());
         Core.init(this);
+        WorkerWatchdog.init(this);
     }
 
     @Override

app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java

@@ -50,6 +50,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
     private SwitchCompat swAuthentication;
     private SwitchCompat swParanoid;
     private TextView tvParanoidHint;
+    private SwitchCompat swWatchdog;
     private SwitchCompat swUpdates;
     private SwitchCompat swCrashReports;
     private SwitchCompat swDebug;
@@ -59,7 +60,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
     private Group grpSearchLocal;
 
     private final static String[] RESET_OPTIONS = new String[]{
-            "badge", "subscriptions", "english", "authentication", "paranoid", "updates", "crash_reports", "debug"
+            "badge", "subscriptions", "english", "authentication", "paranoid", "watchdog", "updates", "crash_reports", "debug"
     };
 
     private final static String[] RESET_QUESTIONS = new String[]{
@@ -82,6 +83,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swAuthentication = view.findViewById(R.id.swAuthentication);
         swParanoid = view.findViewById(R.id.swParanoid);
         tvParanoidHint = view.findViewById(R.id.tvParanoidHint);
+        swWatchdog = view.findViewById(R.id.swWatchdog);
         swUpdates = view.findViewById(R.id.swUpdates);
         swCrashReports = view.findViewById(R.id.swCrashReports);
         swDebug = view.findViewById(R.id.swDebug);
@@ -146,6 +148,14 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             });
         }
 
+        swWatchdog.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("watchdog", checked).apply();
+                WorkerWatchdog.init(getContext());
+            }
+        });
+
         swUpdates.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
@@ -228,6 +238,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swEnglish.setChecked(prefs.getBoolean("english", false));
         swAuthentication.setChecked(prefs.getBoolean("authentication", false));
         swParanoid.setChecked(prefs.getBoolean("paranoid", true));
+        swWatchdog.setChecked(prefs.getBoolean("watchdog", true));
         swUpdates.setChecked(prefs.getBoolean("updates", true));
         swUpdates.setVisibility(Helper.isPlayStoreInstall(getContext()) ? View.GONE : View.VISIBLE);
         swCrashReports.setChecked(prefs.getBoolean("crash_reports", false));

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -222,6 +222,10 @@ public class ServiceSynchronize extends LifecycleService {
                         onOneshot(false);
                         break;
 
+                    case "watchdog":
+                        onWatchdog();
+                        break;
+
                     default:
                         Log.w("Unknown action: " + action);
                 }
@@ -317,6 +321,11 @@ public class ServiceSynchronize extends LifecycleService {
             onReload(true, "oneshot end");
     }
 
+    private void onWatchdog() {
+        EntityLog.log(this, "Service watchdog");
+        // Network events will manage the service
+    }
+
     private void queue_reload(final boolean start, final boolean clear, final String reason) {
         final boolean doStop = started;
         final boolean doStart = (start && isEnabled() && networkState.isSuitable());
@@ -1387,4 +1396,14 @@ public class ServiceSynchronize extends LifecycleService {
                     new Intent(context, ServiceSynchronize.class)
                             .setAction("oneshot_start"));
     }
+
+    static void watchdog(Context context) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        boolean enabled = prefs.getBoolean("enabled", true);
+        int pollInterval = prefs.getInt("poll_interval", 0);
+        if (enabled && pollInterval == 0)
+            ContextCompat.startForegroundService(context,
+                    new Intent(context, ServiceSynchronize.class)
+                            .setAction("watchdog"));
+    }
 }

app/src/main/java/eu/faircode/email/WorkerWatchdog.java

@@ -0,0 +1,74 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    FairEmail is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018-2019 by Marcel Bokhorst (M66B)
+*/
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.preference.PreferenceManager;
+
+import androidx.annotation.NonNull;
+import androidx.work.ExistingPeriodicWorkPolicy;
+import androidx.work.PeriodicWorkRequest;
+import androidx.work.WorkManager;
+import androidx.work.Worker;
+import androidx.work.WorkerParameters;
+
+import java.util.concurrent.TimeUnit;
+
+public class WorkerWatchdog extends Worker {
+    private static final int WATCHDOG_INTERVAL = 60; // minutes
+
+    public WorkerWatchdog(@NonNull Context context, @NonNull WorkerParameters workerParams) {
+        super(context, workerParams);
+        Log.i("Instance " + getName());
+    }
+
+    @NonNull
+    @Override
+    public Result doWork() {
+        Log.i("Running " + getName());
+        ServiceSynchronize.watchdog(getApplicationContext());
+        return Result.success();
+    }
+
+    static void init(Context context) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        boolean watchdog = prefs.getBoolean("watchdog", true);
+        if (watchdog) {
+            Log.i("Queuing " + getName() + " every " + WATCHDOG_INTERVAL + " minutes");
+
+            PeriodicWorkRequest workRequest =
+                    new PeriodicWorkRequest.Builder(WorkerCleanup.class, WATCHDOG_INTERVAL, TimeUnit.MINUTES)
+                            .build();
+            WorkManager.getInstance(context)
+                    .enqueueUniquePeriodicWork(getName(), ExistingPeriodicWorkPolicy.KEEP, workRequest);
+
+            Log.i("Queued " + getName());
+        } else {
+            Log.i("Cancelling " + getName());
+            WorkManager.getInstance(context).cancelUniqueWork(getName());
+            Log.i("Cancelled " + getName());
+        }
+    }
+
+    private static String getName() {
+        return WorkerWatchdog.class.getSimpleName();
+    }
+}

app/src/main/res/layout/fragment_options_misc.xml

@@ -127,6 +127,16 @@
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@id/swParanoid" />
 
+            <androidx.appcompat.widget.SwitchCompat
+                android:id="@+id/swWatchdog"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="12dp"
+                android:text="@string/title_advanced_watchdog"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toBottomOf="@id/tvParanoidHint"
+                app:switchPadding="12dp" />
+
             <androidx.appcompat.widget.SwitchCompat
                 android:id="@+id/swUpdates"
                 android:layout_width="match_parent"
@@ -134,7 +144,7 @@
                 android:layout_marginTop="12dp"
                 android:text="@string/title_advanced_updates"
                 app:layout_constraintStart_toStartOf="parent"
-                app:layout_constraintTop_toBottomOf="@id/tvParanoidHint"
+                app:layout_constraintTop_toBottomOf="@id/swWatchdog"
                 app:switchPadding="12dp" />
 
             <androidx.appcompat.widget.SwitchCompat

app/src/main/res/values/strings.xml

@@ -223,6 +223,7 @@
     <string name="title_advanced_english">Force English language</string>
     <string name="title_advanced_authentication">Show a warning when the receiving server could not authenticate the message</string>
     <string name="title_advanced_paranoid">Extra privacy features</string>
+    <string name="title_advanced_watchdog">Periodically check if FairEmail is still active</string>
     <string name="title_advanced_updates">Check for updates</string>
     <string name="title_advanced_crash_reports">Send error reports</string>
     <string name="title_advanced_debug">Debug mode</string>