initial work toward api 26+

* introduce notification channels
* always use foreground service on 26+

18 files changed, 362 insertions, 178 deletions

diff --git a/build.gradle b/build.gradle
index aa6c0a122..ec296b161 100644
--- a/build.gradle
+++ b/build.gradle
@@ -85,11 +85,11 @@ ext {
 
 android {
 
-    compileSdkVersion 27
+    compileSdkVersion 28
 
     defaultConfig {
         minSdkVersion 16
-        targetSdkVersion 25
+        targetSdkVersion 28
 
         versionCode 239
         versionName "2.1.1 beta (2018-08-28)"
@@ -139,7 +139,6 @@ android {
         }
         buildTypes {
             debug {
-                minSdkVersion 14
                 debuggable true
                 buildTypes.release.signingConfig = null
             }
diff --git a/gradle.properties b/gradle.properties
index fbdb9f362..b3c7a0330 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,2 +1 @@
 org.gradle.jvmargs=-Xmx2048M
-org.gradle.configureondemand=false
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 68382dc23..7a84270ae 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10-all.zip
diff --git a/src/main/AndroidManifest.xml b/src/main/AndroidManifest.xml
index c64f89ef8..e34cb1cb2 100644
--- a/src/main/AndroidManifest.xml
+++ b/src/main/AndroidManifest.xml
@@ -18,6 +18,7 @@
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="com.android.alarm.permission.SET_ALARM" />
     <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
     <uses-permission android:name="android.permission.CAMERA" />
@@ -235,8 +236,7 @@
             android:label="@string/share_location" />
         <activity
             android:name=".ui.ShowLocationActivity"
-            android:label="@string/show_location">
-        </activity>
+            android:label="@string/show_location"></activity>
         <activity
             android:name=".ui.SearchActivity"
             android:label="@string/search_messages" />
diff --git a/src/main/java/de/pixart/messenger/services/BarcodeProvider.java b/src/main/java/de/pixart/messenger/services/BarcodeProvider.java
index 67dc74cc6..5ac2ee016 100644
--- a/src/main/java/de/pixart/messenger/services/BarcodeProvider.java
+++ b/src/main/java/de/pixart/messenger/services/BarcodeProvider.java
@@ -162,7 +162,6 @@ public class BarcodeProvider extends ContentProvider implements ServiceConnectio
             synchronized (this) {
                 if (mXmppConnectionService == null && !mBindingInProcess) {
                     Log.d(Config.LOGTAG, "calling to bind service");
-                    context.startService(intent);
                     context.bindService(intent, this, Context.BIND_AUTO_CREATE);
                     this.mBindingInProcess = true;
                 }
diff --git a/src/main/java/de/pixart/messenger/services/ContactChooserTargetService.java b/src/main/java/de/pixart/messenger/services/ContactChooserTargetService.java
index 5d6469bae..d20f9c1f3 100644
--- a/src/main/java/de/pixart/messenger/services/ContactChooserTargetService.java
+++ b/src/main/java/de/pixart/messenger/services/ContactChooserTargetService.java
@@ -32,7 +32,6 @@ public class ContactChooserTargetService extends ChooserTargetService implements
     public List<ChooserTarget> onGetChooserTargets(ComponentName targetActivityName, IntentFilter matchedFilter) {
         Intent intent = new Intent(this, XmppConnectionService.class);
         intent.setAction("contact_chooser");
-        startService(intent);
         bindService(intent, this, Context.BIND_AUTO_CREATE);
         ArrayList<ChooserTarget> chooserTargets = new ArrayList<>();
         try {
diff --git a/src/main/java/de/pixart/messenger/services/EventReceiver.java b/src/main/java/de/pixart/messenger/services/EventReceiver.java
index 6200a40ce..529741ead 100644
--- a/src/main/java/de/pixart/messenger/services/EventReceiver.java
+++ b/src/main/java/de/pixart/messenger/services/EventReceiver.java
@@ -4,6 +4,7 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.preference.PreferenceManager;
+import android.support.v4.content.ContextCompat;
 import android.util.Log;
 
 import de.pixart.messenger.Config;
@@ -13,26 +14,26 @@ public class EventReceiver extends BroadcastReceiver {
     public static final String SETTING_ENABLED_ACCOUNTS = "enabled_accounts";
 
     @Override
-    public void onReceive(Context context, Intent intent) {
-        Intent mIntentForService = new Intent(context, XmppConnectionService.class);
-        if (intent.getAction() != null) {
-            mIntentForService.setAction(intent.getAction());
+    public void onReceive(final Context context, final Intent originalIntent) {
+        final Intent intentForService = new Intent(context, XmppConnectionService.class);
+        if (originalIntent.getAction() != null) {
+            intentForService.setAction(originalIntent.getAction());
         } else {
-            mIntentForService.setAction("other");
+            intentForService.setAction("other");
         }
-        final String action = intent.getAction();
+        final String action = originalIntent.getAction();
         if (action.equals("ui") || hasEnabledAccounts(context)) {
             try {
-                context.startService(mIntentForService);
+                ContextCompat.startForegroundService(context, intentForService);
             } catch (RuntimeException e) {
                 Log.d(Config.LOGTAG, "EventReceiver was unable to start service");
             }
         } else {
-            Log.d(Config.LOGTAG, "EventReceiver ignored action " + mIntentForService.getAction());
+            Log.d(Config.LOGTAG, "EventReceiver ignored action " + intentForService.getAction());
         }
     }
 
-    public static boolean hasEnabledAccounts(Context context) {
+    public static boolean hasEnabledAccounts(final Context context) {
         return PreferenceManager.getDefaultSharedPreferences(context).getBoolean(SETTING_ENABLED_ACCOUNTS, true);
     }
 
diff --git a/src/main/java/de/pixart/messenger/services/ExportLogsService.java b/src/main/java/de/pixart/messenger/services/ExportLogsService.java
index b485fb91d..c2704490d 100644
--- a/src/main/java/de/pixart/messenger/services/ExportLogsService.java
+++ b/src/main/java/de/pixart/messenger/services/ExportLogsService.java
@@ -1,7 +1,5 @@
 package de.pixart.messenger.services;
 
-import android.app.NotificationManager;
-import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
@@ -10,7 +8,6 @@ import android.os.PowerManager;
 import android.os.PowerManager.WakeLock;
 import android.preference.PreferenceManager;
 import android.support.annotation.BoolRes;
-import android.support.v4.app.NotificationCompat;
 import android.util.Log;
 
 import java.io.BufferedWriter;
@@ -41,19 +38,17 @@ import rocks.xmpp.addr.Jid;
 
 import static de.pixart.messenger.ui.SettingsActivity.USE_MULTI_ACCOUNTS;
 
-public class ExportLogsService extends Service {
+public class ExportLogsService extends XmppConnectionService {
 
     private static final SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
     private static final String DIRECTORY_STRING_FORMAT = FileBackend.getConversationsDirectory("Chats", false) + "%s";
     private static final String MESSAGE_STRING_FORMAT = "(%s) %s: %s\n";
-    private static final int NOTIFICATION_ID = 1;
     private static AtomicBoolean running = new AtomicBoolean(false);
+    boolean ReadableLogsEnabled = false;
     private DatabaseBackend mDatabaseBackend;
     private List<Account> mAccounts;
-    boolean ReadableLogsEnabled = false;
     private WakeLock wakeLock;
     private PowerManager pm;
-    XmppConnectionService mXmppConnectionService;
 
     @Override
     public void onCreate() {
@@ -63,20 +58,19 @@ public class ExportLogsService extends Service {
         ReadableLogsEnabled = ReadableLogs.getBoolean("export_plain_text_logs", getResources().getBoolean(R.bool.plain_text_logs));
         pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
         wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "ExportLogsService");
+        this.startForeground(NotificationService.FOREGROUND_NOTIFICATION_ID, getNotificationService().exportLogsNotification());
     }
 
     @Override
     public int onStartCommand(Intent intent, int flags, int startId) {
         if (running.compareAndSet(false, true)) {
-            new Thread(new Runnable() {
-                @Override
-                public void run() {
-                    export();
-                    stopForeground(true);
-                    WakeLockHelper.release(wakeLock);
-                    running.set(false);
-                    stopSelf();
-                }
+            new Thread(() -> {
+                startForcingForegroundNotification();
+                export();
+                stopForcingForegroundNotification();
+                WakeLockHelper.release(wakeLock);
+                running.set(false);
+                stopSelf();
             }).start();
         }
         return START_NOT_STICKY;
@@ -84,16 +78,9 @@ public class ExportLogsService extends Service {
 
     private void export() {
         wakeLock.acquire();
+        getNotificationService().exportLogsServiceNotification(getNotificationService().exportLogsNotification());
         List<Conversation> conversations = mDatabaseBackend.getConversations(Conversation.STATUS_AVAILABLE);
         conversations.addAll(mDatabaseBackend.getConversations(Conversation.STATUS_ARCHIVED));
-        NotificationManager mNotifyManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getBaseContext());
-        mBuilder.setContentTitle(getString(R.string.app_name))
-                .setContentText(getString(R.string.notification_export_logs_title))
-                .setSmallIcon(R.drawable.ic_import_export_white_24dp)
-                .setProgress(0, 0, true);
-        startForeground(NOTIFICATION_ID, mBuilder.build());
-        mNotifyManager.notify(NOTIFICATION_ID, mBuilder.build());
         if (ReadableLogsEnabled) {
             for (Conversation conversation : conversations) {
                 writeToFile(conversation);
diff --git a/src/main/java/de/pixart/messenger/services/NotificationService.java b/src/main/java/de/pixart/messenger/services/NotificationService.java
index 7fa091478..4cdde8390 100644
--- a/src/main/java/de/pixart/messenger/services/NotificationService.java
+++ b/src/main/java/de/pixart/messenger/services/NotificationService.java
@@ -1,16 +1,23 @@
 package de.pixart.messenger.services;
 
 import android.app.Notification;
+import android.app.NotificationChannel;
+import android.app.NotificationChannelGroup;
+import android.app.NotificationManager;
 import android.app.PendingIntent;
+import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.Typeface;
+import android.media.AudioAttributes;
+import android.media.RingtoneManager;
 import android.net.Uri;
 import android.os.Build;
 import android.os.SystemClock;
 import android.preference.PreferenceManager;
+import android.support.annotation.RequiresApi;
 import android.support.v4.app.NotificationCompat;
 import android.support.v4.app.NotificationCompat.BigPictureStyle;
 import android.support.v4.app.NotificationCompat.Builder;
@@ -46,9 +53,9 @@ import de.pixart.messenger.entities.Conversational;
 import de.pixart.messenger.entities.Message;
 import de.pixart.messenger.persistance.FileBackend;
 import de.pixart.messenger.ui.ConversationsActivity;
-import de.pixart.messenger.ui.EditAccountActivity;
 import de.pixart.messenger.ui.ManageAccountActivity;
 import de.pixart.messenger.ui.TimePreference;
+import de.pixart.messenger.utils.Compatibility;
 import de.pixart.messenger.utils.GeoHelper;
 import de.pixart.messenger.utils.UIHelper;
 import de.pixart.messenger.xmpp.XmppConnection;
@@ -56,39 +63,108 @@ import de.pixart.messenger.xmpp.XmppConnection;
 public class NotificationService {
 
     public static final Object CATCHUP_LOCK = new Object();
+
     private static final String CONVERSATIONS_GROUP = "de.pixart.messenger";
-    private final XmppConnectionService mXmppConnectionService;
-    private final LinkedHashMap<String, ArrayList<Message>> notifications = new LinkedHashMap<>();
     private static final int NOTIFICATION_ID_MULTIPLIER = 1024 * 1024;
     public static final int NOTIFICATION_ID = 2 * NOTIFICATION_ID_MULTIPLIER;
     public static final int FOREGROUND_NOTIFICATION_ID = NOTIFICATION_ID_MULTIPLIER * 4;
     public static final int ERROR_NOTIFICATION_ID = NOTIFICATION_ID_MULTIPLIER * 6;
-    public static final int UPDATE_NOTIFICATION_ID = NOTIFICATION_ID_MULTIPLIER * 8;
+    public static final String MESSAGES_CHANNEL_ID = "messages";
+    public static final String FOREGROUND_CHANNEL_ID = "foreground";
+    public static final String ERROR_CHANNEL_ID = "error";
+
+    private final XmppConnectionService mXmppConnectionService;
+    private final LinkedHashMap<String, ArrayList<Message>> notifications = new LinkedHashMap<>();
+    private final HashMap<Conversation, AtomicInteger> mBacklogMessageCounter = new HashMap<>();
     private Conversation mOpenConversation;
     private boolean mIsInForeground;
     private long mLastNotification;
 
-    private final HashMap<Conversation, AtomicInteger> mBacklogMessageCounter = new HashMap<>();
-
-    public NotificationService(final XmppConnectionService service) {
+    NotificationService(final XmppConnectionService service) {
         this.mXmppConnectionService = service;
     }
 
+    private static boolean displaySnoozeAction(List<Message> messages) {
+        int numberOfMessagesWithoutReply = 0;
+        for (Message message : messages) {
+            if (message.getStatus() == Message.STATUS_RECEIVED) {
+                ++numberOfMessagesWithoutReply;
+            } else {
+                return false;
+            }
+        }
+        return numberOfMessagesWithoutReply >= 3;
+    }
+
     public static Pattern generateNickHighlightPattern(final String nick) {
         return Pattern.compile("(?<=(^|\\s))" + Pattern.quote(nick) + "\\b");
     }
 
+    @RequiresApi(api = Build.VERSION_CODES.O)
+    public void initializeChannels() {
+        final Context c = mXmppConnectionService;
+        NotificationManager notificationManager = c.getSystemService(NotificationManager.class);
+        if (notificationManager == null) {
+            return;
+        }
+        notificationManager.createNotificationChannelGroup(new NotificationChannelGroup("status", c.getString(R.string.notification_group_status_information)));
+        notificationManager.createNotificationChannelGroup(new NotificationChannelGroup("chats", c.getString(R.string.notification_group_messages)));
+
+        final NotificationChannel foregroundServiceChannel = new NotificationChannel(FOREGROUND_CHANNEL_ID,
+                c.getString(R.string.foreground_service_channel_name),
+                NotificationManager.IMPORTANCE_MIN);
+        foregroundServiceChannel.setDescription(c.getString(R.string.foreground_service_channel_description));
+        foregroundServiceChannel.setShowBadge(false);
+        foregroundServiceChannel.setGroup("status");
+        notificationManager.createNotificationChannel(foregroundServiceChannel);
+
+        final NotificationChannel errorChannel = new NotificationChannel(ERROR_CHANNEL_ID,
+                c.getString(R.string.error_channel_name),
+                NotificationManager.IMPORTANCE_LOW);
+        errorChannel.setDescription(c.getString(R.string.error_channel_description));
+        errorChannel.setShowBadge(false);
+        errorChannel.setGroup("status");
+        notificationManager.createNotificationChannel(errorChannel);
+
+        final NotificationChannel messagesChannel = new NotificationChannel(MESSAGES_CHANNEL_ID,
+                c.getString(R.string.messages_channel_name),
+                NotificationManager.IMPORTANCE_HIGH);
+        messagesChannel.setShowBadge(true);
+        messagesChannel.setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION), new AudioAttributes.Builder()
+                .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
+                .setUsage(AudioAttributes.USAGE_NOTIFICATION_RINGTONE)
+                .build());
+        messagesChannel.setLightColor(0xff00ff00);
+        final int dat = 70;
+        final long[] pattern = {0, 3 * dat, dat, dat};
+        messagesChannel.setVibrationPattern(pattern);
+        messagesChannel.enableVibration(true);
+        messagesChannel.enableLights(true);
+        messagesChannel.setGroup("chats");
+        notificationManager.createNotificationChannel(messagesChannel);
+
+        final NotificationChannel silentMessagesChannel = new NotificationChannel("silent_messages",
+                c.getString(R.string.silent_messages_channel_name),
+                NotificationManager.IMPORTANCE_LOW);
+        silentMessagesChannel.setDescription(c.getString(R.string.silent_messages_channel_description));
+        silentMessagesChannel.setShowBadge(true);
+        silentMessagesChannel.setLightColor(0xff00ff00);
+        silentMessagesChannel.enableLights(true);
+        silentMessagesChannel.setGroup("chats");
+        notificationManager.createNotificationChannel(silentMessagesChannel);
+    }
+
     public boolean notify(final Message message) {
         final Conversation conversation = (Conversation) message.getConversation();
         return message.getStatus() == Message.STATUS_RECEIVED
                 && notificationsEnabled()
                 && !conversation.isMuted()
                 && (conversation.alwaysNotify() || wasHighlightedOrPrivate(message))
-                && (!conversation.isWithStranger() || notificationsFromStrangers()
-        );
+                && (!conversation.isWithStranger() || notificationsFromStrangers())
+                ;
     }
 
-    public boolean notificationsEnabled() {
+    private boolean notificationsEnabled() {
         return mXmppConnectionService.getBooleanPreference("show_notification", R.bool.show_notification);
     }
 
@@ -96,7 +172,7 @@ public class NotificationService {
         return mXmppConnectionService.getBooleanPreference("notifications_from_strangers", R.bool.notifications_from_strangers);
     }
 
-    public boolean isQuietHours() {
+    private boolean isQuietHours() {
         if (!mXmppConnectionService.getBooleanPreference("enable_quiet_hours", R.bool.enable_quiet_hours)) {
             return false;
         }
@@ -104,7 +180,6 @@ public class NotificationService {
         final long startTime = preferences.getLong("quiet_hours_start", TimePreference.DEFAULT_VALUE) % Config.MILLISECONDS_IN_DAY;
         final long endTime = preferences.getLong("quiet_hours_end", TimePreference.DEFAULT_VALUE) % Config.MILLISECONDS_IN_DAY;
         final long nowTime = Calendar.getInstance().getTimeInMillis() % Config.MILLISECONDS_IN_DAY;
-
         if (endTime < startTime) {
             return nowTime > startTime || nowTime < endTime;
         } else {
@@ -159,7 +234,7 @@ public class NotificationService {
                 }
             }
         }
-        Log.d(Config.LOGTAG,account.getJid().asBareJid()+": backlog message count="+count);
+        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": backlog message count=" + count);
         return count;
     }
 
@@ -260,9 +335,8 @@ public class NotificationService {
         updateNotification(notify, false);
     }
 
-    public void updateNotification(final boolean notify, boolean summaryOnly) {
+    private void updateNotification(final boolean notify, boolean summaryOnly) {
         final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(mXmppConnectionService);
-
         if (notifications.size() == 0) {
             cancel(NOTIFICATION_ID);
         } else {
@@ -271,15 +345,16 @@ public class NotificationService {
             }
             final Builder mBuilder;
             if (notifications.size() == 1 && Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
-                mBuilder = buildSingleConversations(notifications.values().iterator().next());
+                mBuilder = buildSingleConversations(notifications.values().iterator().next(), notify);
                 modifyForSoundVibrationAndLight(mBuilder, notify, preferences);
                 notify(NOTIFICATION_ID, mBuilder.build());
             } else {
-                mBuilder = buildMultipleConversation();
+                mBuilder = buildMultipleConversation(notify);
+                mBuilder.setGroupAlertBehavior(NotificationCompat.GROUP_ALERT_CHILDREN);
                 modifyForSoundVibrationAndLight(mBuilder, notify, preferences);
                 if (!summaryOnly) {
                     for (Map.Entry<String, ArrayList<Message>> entry : notifications.entrySet()) {
-                        Builder singleBuilder = buildSingleConversations(entry.getValue());
+                        Builder singleBuilder = buildSingleConversations(entry.getValue(), notify);
                         singleBuilder.setGroup(CONVERSATIONS_GROUP);
                         setNotificationColor(singleBuilder);
                         notify(entry.getKey(), NOTIFICATION_ID, singleBuilder.build());
@@ -330,9 +405,8 @@ public class NotificationService {
         }
     }
 
-    private Builder buildMultipleConversation() {
-        final Builder mBuilder = new NotificationCompat.Builder(
-                mXmppConnectionService);
+    private Builder buildMultipleConversation(final boolean notify) {
+        final Builder mBuilder = new NotificationCompat.Builder(mXmppConnectionService, notify ? "messages" : "silent_messages");
         final NotificationCompat.InboxStyle style = new NotificationCompat.InboxStyle();
         style.setBigContentTitle(notifications.size()
                 + " "
@@ -378,8 +452,8 @@ public class NotificationService {
         return mBuilder;
     }
 
-    private Builder buildSingleConversations(final ArrayList<Message> messages) {
-        final Builder mBuilder = new NotificationCompat.Builder(mXmppConnectionService);
+    private Builder buildSingleConversations(final ArrayList<Message> messages, final boolean notify) {
+        final Builder mBuilder = new NotificationCompat.Builder(mXmppConnectionService, notify ? "messages" : "silent_messages");
         if (messages.size() >= 1) {
             final Conversation conversation = (Conversation) messages.get(0).getConversation();
             final UnreadConversation.Builder mUnreadBuilder = new UnreadConversation.Builder(conversation.getName().toString());
@@ -407,8 +481,7 @@ public class NotificationService {
                         R.drawable.ic_reply_white_24dp,
                         replyLabel,
                         createReplyIntent(conversation, false)).addRemoteInput(remoteInput).build();
-                NotificationCompat.Action wearReplyAction = new NotificationCompat.Action.Builder(
-                        R.drawable.ic_wear_reply,
+                NotificationCompat.Action wearReplyAction = new NotificationCompat.Action.Builder(R.drawable.ic_wear_reply,
                         replyLabel,
                         createReplyIntent(conversation, true)).addRemoteInput(remoteInput).build();
                 mBuilder.extend(new NotificationCompat.WearableExtender().addAction(wearReplyAction));
@@ -473,18 +546,6 @@ public class NotificationService {
         return mBuilder;
     }
 
-    private static boolean displaySnoozeAction(List<Message> messages) {
-        int numberOfMessagesWithoutReply = 0;
-        for (Message message : messages) {
-            if (message.getStatus() == Message.STATUS_RECEIVED) {
-                ++numberOfMessagesWithoutReply;
-            } else {
-                return false;
-            }
-        }
-        return numberOfMessagesWithoutReply >= 3;
-    }
-
     private void modifyForImage(final Builder builder, final UnreadConversation.Builder uBuilder,
                                 final Message message, final ArrayList<Message> messages) {
         try {
@@ -545,7 +606,7 @@ public class NotificationService {
                     styledString.setSpan(new StyleSpan(Typeface.BOLD), 0, name.length(), 0);
                     builder.setContentText(styledString);
                 } else {
-                    builder.setContentText(mXmppConnectionService.getResources().getQuantityString(R.plurals.x_messages,count,count));
+                    builder.setContentText(mXmppConnectionService.getResources().getQuantityString(R.plurals.x_messages, count, count));
                 }
             }
         }
@@ -596,7 +657,7 @@ public class NotificationService {
 
     private CharSequence getMergedBodies(final ArrayList<Message> messages) {
         final StringBuilder text = new StringBuilder();
-        for(Message message : messages) {
+        for (Message message : messages) {
             if (text.length() != 0) {
                 text.append("\n");
             }
@@ -606,7 +667,7 @@ public class NotificationService {
     }
 
     private PendingIntent createShowLocationIntent(final Message message) {
-        Iterable<Intent> intents = GeoHelper.createGeoIntentsFromMessage(message, this.mXmppConnectionService.getApplicationContext());
+        Iterable<Intent> intents = GeoHelper.createGeoIntentsFromMessage(message, mXmppConnectionService);
         for (Intent intent : intents) {
             if (intent.resolveActivity(mXmppConnectionService.getPackageManager()) != null) {
                 return PendingIntent.getActivity(mXmppConnectionService, generateRequestCode(message.getConversation(), 18), intent, PendingIntent.FLAG_UPDATE_CURRENT);
@@ -676,7 +737,7 @@ public class NotificationService {
         return PendingIntent.getService(mXmppConnectionService, generateRequestCode(conversation, 16), intent, PendingIntent.FLAG_UPDATE_CURRENT);
     }
 
-    public PendingIntent createSnoozeIntent(Conversation conversation) {
+    private PendingIntent createSnoozeIntent(Conversation conversation) {
         final Intent intent = new Intent(mXmppConnectionService, XmppConnectionService.class);
         intent.setAction(XmppConnectionService.ACTION_SNOOZE);
         intent.putExtra("uuid", conversation.getUuid());
@@ -736,52 +797,61 @@ public class NotificationService {
     }
 
     public Notification createForegroundNotification() {
-        final NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(mXmppConnectionService);
-        List<Account> accounts = mXmppConnectionService.getAccounts();
-        String status;
-        Account mAccount = null;
-        Log.d(Config.LOGTAG, "Accounts size " + accounts.size());
-        if (accounts.size() == 1) {
-            mAccount = accounts.get(0);
-            if (mAccount.getStatus() == Account.State.ONLINE) {
-                status = "(" + mXmppConnectionService.getString(R.string.account_status_online) + ")";
-            } else if (mAccount.getStatus() == Account.State.CONNECTING) {
-                status = "(" + mXmppConnectionService.getString(R.string.account_status_connecting) + ")";
-            } else {
-                status = "(" + mXmppConnectionService.getString(R.string.account_status_offline) + ")";
-            }
-        } else if (accounts.size() > 1) {
-            status = ""; // todo: status for multiple accounts???
-        } else {
-            status = "(" + mXmppConnectionService.getString(R.string.account_status_offline) + ")";
-        }
-        status = " " + status;
-        Log.d(Config.LOGTAG, "Status: " + status);
-        mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.conversations_foreground_service) + status);
-        if (Config.SHOW_CONNECTED_ACCOUNTS) {
+        final Notification.Builder mBuilder = new Notification.Builder(mXmppConnectionService);
+        mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.conversations_foreground_service));
+        if (Compatibility.twentySix() || Config.SHOW_CONNECTED_ACCOUNTS) {
+            List<Account> accounts = mXmppConnectionService.getAccounts();
             int enabled = 0;
             int connected = 0;
-            for (Account account : accounts) {
-                if (account.isOnlineAndConnected()) {
-                    connected++;
-                    enabled++;
-                } else if (account.isEnabled()) {
-                    enabled++;
+            String status;
+            Account mAccount = null;
+            if (accounts != null) {
+                for (Account account : accounts) {
+                    if (account.isOnlineAndConnected()) {
+                        connected++;
+                        enabled++;
+                    } else if (account.isEnabled()) {
+                        enabled++;
+                    }
+                }
+                if (accounts.size() == 1) {
+                    mAccount = accounts.get(0);
+                    if (mAccount.getStatus() == Account.State.ONLINE) {
+                        status = "(" + mXmppConnectionService.getString(R.string.account_status_online) + ")";
+                        status = " " + status;
+                        Log.d(Config.LOGTAG, "Status: " + status);
+                        mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.conversations_foreground_service) + status);
+                    } else if (mAccount.getStatus() == Account.State.CONNECTING) {
+                        status = "(" + mXmppConnectionService.getString(R.string.account_status_connecting) + ")";
+                        status = " " + status;
+                        Log.d(Config.LOGTAG, "Status: " + status);
+                        mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.conversations_foreground_service) + status);
+                    } else {
+                        status = "(" + mXmppConnectionService.getString(R.string.account_status_offline) + ")";
+                        status = " " + status;
+                        Log.d(Config.LOGTAG, "Status: " + status);
+                        mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.conversations_foreground_service) + status);
+                    }
+                } else if (accounts.size() > 1) {
+                    mBuilder.setContentText(mXmppConnectionService.getString(R.string.connected_accounts, connected, enabled));
+                } else {
+                    status = "(" + mXmppConnectionService.getString(R.string.account_status_offline) + ")";
+                    status = " " + status;
+                    Log.d(Config.LOGTAG, "Status: " + status);
+                    mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.conversations_foreground_service) + status);
                 }
+            } else {
+                mBuilder.setContentText(mXmppConnectionService.getString(R.string.touch_to_open_conversations));
             }
-            mBuilder.setContentText(mXmppConnectionService.getString(R.string.connected_accounts, connected, enabled));
         } else {
             mBuilder.setContentText(mXmppConnectionService.getString(R.string.touch_to_open_conversations));
         }
         mBuilder.setContentIntent(createOpenConversationsIntent());
         mBuilder.setWhen(0);
-        mBuilder.setPriority(Config.SHOW_CONNECTED_ACCOUNTS ? NotificationCompat.PRIORITY_DEFAULT : NotificationCompat.PRIORITY_MIN);
-        if (accounts.size() == 1 && accounts.get(0).getStatus() == Account.State.ONLINE) {
-            mBuilder.setSmallIcon(R.drawable.ic_link_white_24dp);
-        } else if (accounts.size() > 1) {
-            mBuilder.setSmallIcon(R.drawable.ic_link_white_24dp); // todo: status for multiple accounts???
-        } else {
-            mBuilder.setSmallIcon(R.drawable.ic_unlink_white_24dp);
+        mBuilder.setPriority(Notification.PRIORITY_LOW);
+        mBuilder.setSmallIcon(R.drawable.ic_link_white_24dp);
+        if (Compatibility.twentySix()) {
+            mBuilder.setChannelId(FOREGROUND_CHANNEL_ID);
         }
         return mBuilder.build();
     }
@@ -801,10 +871,10 @@ public class NotificationService {
                 errors.add(account);
             }
         }
-        if (mXmppConnectionService.showForegroundService()) {
+        if (Compatibility.keepForegroundService(mXmppConnectionService)) {
             notify(FOREGROUND_NOTIFICATION_ID, createForegroundNotification());
         }
-        final NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(mXmppConnectionService);
+        final Notification.Builder mBuilder = new Notification.Builder(mXmppConnectionService);
         if (errors.size() == 0) {
             cancel(ERROR_NOTIFICATION_ID);
             return;
@@ -819,38 +889,70 @@ public class NotificationService {
                 mXmppConnectionService.getString(R.string.try_again),
                 createTryAgainIntent());
         mBuilder.setDeleteIntent(createDismissErrorIntent());
-        mBuilder.setVisibility(NotificationCompat.VISIBILITY_PRIVATE);
-        mBuilder.setSmallIcon(R.drawable.ic_warning_white_24dp);
-        mBuilder.setLocalOnly(true);
-        mBuilder.setPriority(NotificationCompat.PRIORITY_LOW);
-        if (errors.size() == 1) {
-            Intent intent = new Intent(mXmppConnectionService, EditAccountActivity.class);
-            Account mAccount = mXmppConnectionService.getAccounts().get(0);
-            intent.putExtra("jid", mAccount.getJid().asBareJid().toString());
-            intent.putExtra("init", false);
-            mBuilder.setContentIntent(PendingIntent.getActivity(mXmppConnectionService,
-                    145,
-                    intent,
-                    PendingIntent.FLAG_UPDATE_CURRENT));
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            mBuilder.setVisibility(NotificationCompat.VISIBILITY_PRIVATE);
+            mBuilder.setSmallIcon(R.drawable.ic_warning_white_24dp);
         } else {
-            mBuilder.setContentIntent(PendingIntent.getActivity(mXmppConnectionService,
-                    145,
-                    new Intent(mXmppConnectionService, ManageAccountActivity.class),
-                    PendingIntent.FLAG_UPDATE_CURRENT));
+            mBuilder.setSmallIcon(R.drawable.ic_warning_white_24dp);
+        }
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT_WATCH) {
+            mBuilder.setLocalOnly(true);
+        }
+        mBuilder.setPriority(Notification.PRIORITY_LOW);
+        mBuilder.setContentIntent(PendingIntent.getActivity(mXmppConnectionService,
+                145,
+                new Intent(mXmppConnectionService, ManageAccountActivity.class),
+                PendingIntent.FLAG_UPDATE_CURRENT));
+        if (Compatibility.twentySix()) {
+            mBuilder.setChannelId(ERROR_CHANNEL_ID);
         }
         notify(ERROR_NOTIFICATION_ID, mBuilder.build());
     }
 
-    public Notification updateFileAddingNotification(int current, Message message) {
-        final NotificationManagerCompat notificationManager = NotificationManagerCompat.from(mXmppConnectionService);
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(mXmppConnectionService);
+    public void updateFileAddingNotification(int current, Message message) {
+        Notification.Builder mBuilder = new Notification.Builder(mXmppConnectionService);
         mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.transcoding_video));
         mBuilder.setProgress(100, current, false);
         mBuilder.setSmallIcon(R.drawable.ic_hourglass_empty_white_24dp);
         mBuilder.setContentIntent(createContentIntent(message.getConversation()));
+        if (Compatibility.twentySix()) {
+            mBuilder.setChannelId(FOREGROUND_CHANNEL_ID);
+        }
         Notification notification = mBuilder.build();
         notify(FOREGROUND_NOTIFICATION_ID, notification);
-        return notification;
+    }
+
+    public Notification exportLogsNotification() {
+        Notification.Builder mBuilder = new Notification.Builder(mXmppConnectionService);
+        mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.app_name));
+        mBuilder.setContentText(mXmppConnectionService.getString(R.string.notification_export_logs_title));
+        mBuilder.setProgress(0, 0, true);
+        mBuilder.setSmallIcon(R.drawable.ic_import_export_white_24dp);
+        if (Compatibility.twentySix()) {
+            mBuilder.setChannelId(FOREGROUND_CHANNEL_ID);
+        }
+        return mBuilder.build();
+    }
+
+    public void exportLogsServiceNotification(Notification notification) {
+        notify(FOREGROUND_NOTIFICATION_ID, notification);
+    }
+
+    public Notification AppUpdateNotification(PendingIntent intent, String version, String filesize) {
+        Notification.Builder mBuilder = new Notification.Builder(mXmppConnectionService);
+        mBuilder.setContentTitle(mXmppConnectionService.getString(R.string.app_name));
+        mBuilder.setContentText(mXmppConnectionService.getString(R.string.notification_export_logs_title));
+        mBuilder.setContentText(String.format(mXmppConnectionService.getString(R.string.update_available), version, filesize));
+        mBuilder.setSmallIcon(R.drawable.ic_update_notification);
+        mBuilder.setContentIntent(intent);
+        if (Compatibility.twentySix()) {
+            mBuilder.setChannelId(FOREGROUND_CHANNEL_ID);
+        }
+        return mBuilder.build();
+    }
+
+    public void AppUpdateServiceNotification(Notification notification) {
+        notify(FOREGROUND_NOTIFICATION_ID, notification);
     }
 
     private void notify(String tag, int id, Notification notification) {
diff --git a/src/main/java/de/pixart/messenger/services/UpdateService.java b/src/main/java/de/pixart/messenger/services/UpdateService.java
index 3b3829290..bf5242939 100644
--- a/src/main/java/de/pixart/messenger/services/UpdateService.java
+++ b/src/main/java/de/pixart/messenger/services/UpdateService.java
@@ -1,14 +1,11 @@
 package de.pixart.messenger.services;
 
-import android.app.Notification;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.os.AsyncTask;
 import android.os.Handler;
 import android.os.Looper;
-import android.support.v4.app.NotificationCompat;
-import android.support.v4.app.NotificationManagerCompat;
 import android.util.Log;
 import android.widget.Toast;
 
@@ -27,12 +24,12 @@ import de.pixart.messenger.R;
 import de.pixart.messenger.ui.UpdaterActivity;
 
 import static de.pixart.messenger.http.HttpConnectionManager.getProxy;
-import static de.pixart.messenger.services.NotificationService.UPDATE_NOTIFICATION_ID;
 
 public class UpdateService extends AsyncTask<String, Object, UpdateService.Wrapper> {
     private boolean mUseTor;
     private Context context;
     private String store;
+    private NotificationService getNotificationService;
     public UpdateService() {
     }
 
@@ -40,6 +37,7 @@ public class UpdateService extends AsyncTask<String, Object, UpdateService.Wrapp
         this.context = context;
         this.store = Store;
         this.mUseTor = mXmppConnectionService.useTorToConnect();
+        this.getNotificationService = mXmppConnectionService.getNotificationService();
     }
 
     @Override
@@ -145,14 +143,7 @@ public class UpdateService extends AsyncTask<String, Object, UpdateService.Wrapp
         intent.putExtra("changelog", changelog);
         intent.putExtra("store", store);
         PendingIntent pi = PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
-        final NotificationManagerCompat notificationManager = NotificationManagerCompat.from(context);
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context);
-        mBuilder.setContentTitle(context.getString(R.string.update_service));
-        mBuilder.setContentText(String.format(context.getString(R.string.update_available), version, filesize));
-        mBuilder.setSmallIcon(R.drawable.ic_update_notification);
-        mBuilder.setContentIntent(pi);
-        Notification notification = mBuilder.build();
-        notificationManager.notify(UPDATE_NOTIFICATION_ID, notification);
+        getNotificationService.AppUpdateServiceNotification(getNotificationService.AppUpdateNotification(pi, version, filesize));
     }
 
     private int checkVersion(String remoteVersion, String installedVersion) {
diff --git a/src/main/java/de/pixart/messenger/services/XmppConnectionService.java b/src/main/java/de/pixart/messenger/services/XmppConnectionService.java
index 896061457..af94d017b 100644
--- a/src/main/java/de/pixart/messenger/services/XmppConnectionService.java
+++ b/src/main/java/de/pixart/messenger/services/XmppConnectionService.java
@@ -1,5 +1,6 @@
 package de.pixart.messenger.services;
 
+import android.Manifest;
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.app.AlarmManager;
@@ -114,6 +115,7 @@ import de.pixart.messenger.ui.SettingsActivity;
 import de.pixart.messenger.ui.UiCallback;
 import de.pixart.messenger.ui.interfaces.OnAvatarPublication;
 import de.pixart.messenger.ui.interfaces.OnSearchResultsAvailable;
+import de.pixart.messenger.utils.Compatibility;
 import de.pixart.messenger.utils.ConversationsFileObserver;
 import de.pixart.messenger.utils.CryptoHelper;
 import de.pixart.messenger.utils.ExceptionHelper;
@@ -170,8 +172,6 @@ public class XmppConnectionService extends Service {
     public static final String ACTION_FCM_MESSAGE_RECEIVED = "fcm_message_received";
     public static final String FDroid = "org.fdroid.fdroid";
     public static final String PlayStore = "com.android.vending";
-    public static final String Yalp = "com.github.yeriomin.yalpstore";
-    private static final String ACTION_MERGE_PHONE_CONTACTS = "merge_phone_contacts";
     private static final String SETTING_LAST_ACTIVITY_TS = "last_activity_timestamp";
 
     static {
@@ -234,6 +234,7 @@ public class XmppConnectionService extends Service {
     ) {
         @Override
         public void onEvent(int event, String path) {
+            Log.d(Config.LOGTAG, "event " + event + " path=" + path);
             markFileDeleted(path);
         }
     };
@@ -244,17 +245,16 @@ public class XmppConnectionService extends Service {
         @Override
         public void onChange(boolean selfChange) {
             super.onChange(selfChange);
-            Intent intent = new Intent(getApplicationContext(),
-                    XmppConnectionService.class);
-            intent.setAction(ACTION_MERGE_PHONE_CONTACTS);
-            startService(intent);
+            if (restoredFromDatabaseLatch.getCount() == 0) {
+                loadPhoneContacts();
+            }
         }
     };
     private MemorizingTrustManager mMemorizingTrustManager;
     private NotificationService mNotificationService = new NotificationService(this);
     private ShortcutService mShortcutService = new ShortcutService(this);
     private AtomicBoolean mInitialAddressbookSyncCompleted = new AtomicBoolean(false);
-    private AtomicBoolean mForceForegroundService = new AtomicBoolean(false);
+    protected AtomicBoolean mForceForegroundService = new AtomicBoolean(false);
     private OnMessagePacketReceived mMessageParser = new MessageParser(this);
     private OnPresencePacketReceived mPresenceParser = new PresenceParser(this);
     private IqParser mIqParser = new IqParser(this);
@@ -590,11 +590,6 @@ public class XmppConnectionService extends Service {
                         resetAllAttemptCounts(true, false);
                     }
                     break;
-                case ACTION_MERGE_PHONE_CONTACTS:
-                    if (restoredFromDatabaseLatch.getCount() == 0) {
-                        loadPhoneContacts();
-                    }
-                    return START_STICKY;
                 case Intent.ACTION_SHUTDOWN:
                     logoutAndSave(true);
                     return START_NOT_STICKY;
@@ -1094,6 +1089,9 @@ public class XmppConnectionService extends Service {
         Resolver.init(this);
         this.mRandom = new SecureRandom();
         updateMemorizingTrustmanager();
+        if (Compatibility.twentySix()) {
+            mNotificationService.initializeChannels();
+        }
         final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
         final int cacheSize = maxMemory / 8;
         this.mBitmapCache = new LruCache<String, Bitmap>(cacheSize) {
@@ -1120,7 +1118,10 @@ public class XmppConnectionService extends Service {
         editor.apply();
         restoreFromDatabase();
 
-        getContentResolver().registerContentObserver(ContactsContract.Contacts.CONTENT_URI, true, contactObserver);
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M || ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CONTACTS) == PackageManager.PERMISSION_GRANTED) {
+            //TODO get this restarted if users gives permission
+            getContentResolver().registerContentObserver(ContactsContract.Contacts.CONTENT_URI, true, contactObserver);
+        }
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M || ContextCompat.checkSelfPermission(this, android.Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
             Log.d(Config.LOGTAG, "starting file observer");
             new Thread(fileObserver::startWatching).start();
@@ -1203,7 +1204,7 @@ public class XmppConnectionService extends Service {
     }
 
     public void toggleForegroundService() {
-        if (mForceForegroundService.get() || (showForegroundService())) {
+        if (mForceForegroundService.get() || (Compatibility.keepForegroundService(this) && hasEnabledAccounts())) {
             startForeground(NotificationService.FOREGROUND_NOTIFICATION_ID, this.mNotificationService.createForegroundNotification());
             Log.d(Config.LOGTAG, "started foreground service");
         } else {
@@ -1215,7 +1216,8 @@ public class XmppConnectionService extends Service {
     @Override
     public void onTaskRemoved(final Intent rootIntent) {
         super.onTaskRemoved(rootIntent);
-        if (showForegroundService() || mForceForegroundService.get()) {
+        //TODO check for accounts enabled
+        if ((Compatibility.keepForegroundService(this) && hasEnabledAccounts()) || mForceForegroundService.get()) {
             Log.d(Config.LOGTAG, "ignoring onTaskRemoved because foreground service is activated");
         } else {
             this.logoutAndSave(false);
@@ -2195,6 +2197,7 @@ public class XmppConnectionService extends Service {
             updateAccountUi();
             getNotificationService().updateErrorNotification();
             syncEnabledAccountSetting();
+            toggleForegroundService();
         }
     }
 
@@ -2637,6 +2640,9 @@ public class XmppConnectionService extends Service {
     }
 
     private boolean hasEnabledAccounts() {
+        if (this.accounts == null) {
+            return true; // set to true if accounts could not be fetched - used for notifications
+        }
         for (Account account : this.accounts) {
             if (account.isEnabled()) {
                 return true;
@@ -4330,10 +4336,6 @@ public class XmppConnectionService extends Service {
         return getBooleanPreference(SettingsActivity.BLIND_TRUST_BEFORE_VERIFICATION, R.bool.btbv);
     }
 
-    public boolean showForegroundService() {
-        return getBooleanPreference(SettingsActivity.SHOW_FOREGROUND_SERVICE, R.bool.show_foreground_service);
-    }
-
     public void ScheduleAutomaticExport() {
         //start export log service every day at given time
         if (Config.ExportLogs) {
diff --git a/src/main/java/de/pixart/messenger/ui/SettingsActivity.java b/src/main/java/de/pixart/messenger/ui/SettingsActivity.java
index 1ace03e5e..4bf9d26cc 100644
--- a/src/main/java/de/pixart/messenger/ui/SettingsActivity.java
+++ b/src/main/java/de/pixart/messenger/ui/SettingsActivity.java
@@ -17,6 +17,7 @@ import android.preference.PreferenceCategory;
 import android.preference.PreferenceManager;
 import android.preference.PreferenceScreen;
 import android.support.annotation.NonNull;
+import android.support.v4.content.ContextCompat;
 import android.support.v7.app.AlertDialog;
 import android.util.Log;
 import android.view.LayoutInflater;
@@ -541,7 +542,7 @@ public class SettingsActivity extends XmppActivity implements
     }
 
     private void startExport() {
-        startService(new Intent(getApplicationContext(), ExportLogsService.class));
+        ContextCompat.startForegroundService(this, new Intent(this, ExportLogsService.class));
     }
 
     private void displayToast(final String msg) {
diff --git a/src/main/java/de/pixart/messenger/ui/SettingsFragment.java b/src/main/java/de/pixart/messenger/ui/SettingsFragment.java
index b40875f7c..ec4898f89 100644
--- a/src/main/java/de/pixart/messenger/ui/SettingsFragment.java
+++ b/src/main/java/de/pixart/messenger/ui/SettingsFragment.java
@@ -10,6 +10,7 @@ import android.text.TextUtils;
 
 import de.pixart.messenger.Config;
 import de.pixart.messenger.R;
+import de.pixart.messenger.utils.Compatibility;
 
 public class SettingsFragment extends PreferenceFragment {
 
@@ -30,6 +31,7 @@ public class SettingsFragment extends PreferenceFragment {
                 mCategory.removePreference(cleanPrivateStorage);
             }
         }
+        Compatibility.removeUnusedPreferences(this);
 
         if (!TextUtils.isEmpty(page)) {
             openPreferenceScreen(page);
diff --git a/src/main/java/de/pixart/messenger/ui/XmppActivity.java b/src/main/java/de/pixart/messenger/ui/XmppActivity.java
index 3ab6bfc6a..acb970e82 100644
--- a/src/main/java/de/pixart/messenger/ui/XmppActivity.java
+++ b/src/main/java/de/pixart/messenger/ui/XmppActivity.java
@@ -536,7 +536,11 @@ public abstract class XmppActivity extends ActionBarActivity {
         intent.setAction(Intent.ACTION_SEND);
         intent.setData(uri);
         intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
-        startService(intent);
+        try {
+            startService(intent);
+        } catch (Exception e) {
+            Log.e(Config.LOGTAG, "unable to delegate uri permission", e);
+        }
     }
 
     protected void inviteToConversation(Conversation conversation) {
diff --git a/src/main/java/de/pixart/messenger/utils/Compatibility.java b/src/main/java/de/pixart/messenger/utils/Compatibility.java
new file mode 100644
index 000000000..95d7b4ef2
--- /dev/null
+++ b/src/main/java/de/pixart/messenger/utils/Compatibility.java
@@ -0,0 +1,66 @@
+package de.pixart.messenger.utils;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.os.Build;
+import android.preference.Preference;
+import android.preference.PreferenceCategory;
+import android.preference.PreferenceManager;
+import android.preference.PreferenceScreen;
+import android.support.annotation.BoolRes;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import de.pixart.messenger.R;
+import de.pixart.messenger.ui.SettingsActivity;
+import de.pixart.messenger.ui.SettingsFragment;
+
+public class Compatibility {
+    private static final List<String> UNUSED_SETTINGS_POST_TWENTYSIX = Arrays.asList(
+            SettingsActivity.SHOW_FOREGROUND_SERVICE,
+            "led",
+            "notification_ringtone",
+            "notification_headsup",
+            "vibrate_on_notification");
+    private static final List<String> UNUESD_SETTINGS_PRE_TWENTYSIX = Collections.singletonList("more_notification_settings");
+
+    public static boolean twentySix() {
+        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.O;
+    }
+
+    private static boolean getBooleanPreference(Context context, String name, @BoolRes int res) {
+        return getPreferences(context).getBoolean(name, context.getResources().getBoolean(res));
+    }
+
+    private static SharedPreferences getPreferences(final Context context) {
+        return PreferenceManager.getDefaultSharedPreferences(context);
+    }
+
+    public static boolean keepForegroundService(Context context) {
+        return twentySix() || getBooleanPreference(context, SettingsActivity.SHOW_FOREGROUND_SERVICE, R.bool.show_foreground_service);
+    }
+
+    public static void removeUnusedPreferences(SettingsFragment settingsFragment) {
+        List<PreferenceScreen> screens = Arrays.asList(
+                (PreferenceScreen) settingsFragment.findPreference("notifications"));
+        List<PreferenceCategory> categories = Arrays.asList(
+                (PreferenceCategory) settingsFragment.findPreference("general"));
+        for (String key : (twentySix() ? UNUSED_SETTINGS_POST_TWENTYSIX : UNUESD_SETTINGS_PRE_TWENTYSIX)) {
+            Preference preference = settingsFragment.findPreference(key);
+            if (preference != null) {
+                for (PreferenceScreen screen : screens) {
+                    if (screen != null) {
+                        screen.removePreference(preference);
+                    }
+                }
+                for (PreferenceCategory category : categories) {
+                    if (category != null) {
+                        category.removePreference(preference);
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/de/pixart/messenger/utils/ConversationsFileObserver.java b/src/main/java/de/pixart/messenger/utils/ConversationsFileObserver.java
index 4e275df3f..73d5589e4 100644
--- a/src/main/java/de/pixart/messenger/utils/ConversationsFileObserver.java
+++ b/src/main/java/de/pixart/messenger/utils/ConversationsFileObserver.java
@@ -2,12 +2,15 @@ package de.pixart.messenger.utils;
 
 
 import android.os.FileObserver;
+import android.util.Log;
 
 import java.io.File;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Stack;
 
+import de.pixart.messenger.Config;
+
 /**
  * Copyright (C) 2012 Bartek Przybylski
  * Copyright (C) 2015 ownCloud Inc.
@@ -19,7 +22,7 @@ public abstract class ConversationsFileObserver {
     private final String path;
     private final List<SingleFileObserver> mObservers = new ArrayList<>();
 
-    public ConversationsFileObserver(String path) {
+    protected ConversationsFileObserver(String path) {
         this.path = path;
     }
 
@@ -88,13 +91,17 @@ public abstract class ConversationsFileObserver {
     private class SingleFileObserver extends FileObserver {
         private final String path;
 
-        public SingleFileObserver(String path, int mask) {
+        SingleFileObserver(String path, int mask) {
             super(path, mask);
             this.path = path;
         }
 
         @Override
         public void onEvent(int event, String filename) {
+            if (filename == null) {
+                Log.d(Config.LOGTAG, "ignored file event with NULL filename (event=" + event + ")");
+                return;
+            }
             ConversationsFileObserver.this.onEvent(event, path + '/' + filename);
         }
 
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index 1481bc6cc..3c1e766da 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -814,4 +814,15 @@
     <string name="pref_quick_share_attachment_choice">Attachment choice</string>
     <string name="phone_book">Address book</string>
     <string name="unable_to_save_recording">Unable to save recording</string>
+    <string name="foreground_service_channel_name">Foreground service</string>
+    <string name="foreground_service_channel_description">This notification category is used to display a permanent notification indicating that Conversations is running.</string>
+    <string name="notification_group_status_information">Status Information</string>
+    <string name="error_channel_name">Connectivity Problems</string>
+    <string name="error_channel_description">This notification category is used to display a notification in case there is a problem connecting to an account.</string>
+    <string name="notification_group_messages">Messages</string>
+    <string name="messages_channel_name">Messages</string>
+    <string name="silent_messages_channel_name">Silent messages</string>
+    <string name="silent_messages_channel_description">This notification group is used to display notifications that should not trigger any sound. For example when being active on another device (Grace Period).</string>
+    <string name="pref_more_notification_settings">Notification Settings</string>
+    <string name="pref_more_notification_settings_summary">Importance, Sound, Vibrate</string>
 </resources>
diff --git a/src/main/res/xml/preferences.xml b/src/main/res/xml/preferences.xml
index b4edb7a34..73d817782 100644
--- a/src/main/res/xml/preferences.xml
+++ b/src/main/res/xml/preferences.xml
@@ -152,6 +152,20 @@
             android:key="notifications_from_strangers"
             android:summary="@string/pref_notifications_from_strangers_summary"
             android:title="@string/pref_notifications_from_strangers" />
+        <PreferenceScreen
+            android:dependency="show_notification"
+            android:key="more_notification_settings"
+            android:summary="@string/pref_more_notification_settings_summary"
+            android:title="@string/pref_more_notification_settings">
+            <intent android:action="android.settings.CHANNEL_NOTIFICATION_SETTINGS">
+                <extra
+                    android:name="android.provider.extra.APP_PACKAGE"
+                    android:value="@string/applicationId" />
+                <extra
+                    android:name="android.provider.extra.CHANNEL_ID"
+                    android:value="messages" />
+            </intent>
+        </PreferenceScreen>
     </PreferenceScreen>
     <!--Attachments-->
     <PreferenceScreen