unfinished code

# Conflicts:
#	app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailAnnounceFragment.java
#	app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailAssignmentFragment.java
#	app/src/main/java/de/sebse/fuplanner/services/KVV/KVVModuleList.java

.gitignore

@@ -7,3 +7,4 @@
 /build
 /captures
 .externalNativeBuild
+app/release/*

app/build.gradle

@@ -7,8 +7,8 @@ android {
         applicationId "de.sebse.fuplanner"
         minSdkVersion 15
         targetSdkVersion 28
-        versionCode 10
-        versionName "1.2.2"
+        versionCode 16
+        versionName "1.3.5"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     buildTypes {

app/src/main/AndroidManifest.xml

@@ -2,28 +2,46 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="de.sebse.fuplanner">
 
+    <uses-permission
+        android:name="android.permission.AUTHENTICATE_ACCOUNTS"
+        android:maxSdkVersion="22" />
+    <uses-permission
+        android:name="android.permission.GET_ACCOUNTS"
+        android:maxSdkVersion="22" />
     <uses-permission android:name="android.permission.INTERNET" />
-
+    <uses-permission
+        android:name="android.permission.MANAGE_ACCOUNTS"
+        android:maxSdkVersion="22" />
+    <uses-permission
+        android:name="android.permission.USE_CREDENTIALS"
+        android:maxSdkVersion="22" />
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 
+    <!-- To auto-complete the email text field in the login form with the user's emails -->
+    <uses-permission android:name="android.permission.READ_PROFILE" />
+    <uses-permission android:name="android.permission.READ_CONTACTS" />
+    <uses-permission android:name="android.permission.WRITE_SYNC_SETTINGS" />
+    <uses-permission android:name="android.permission.READ_SYNC_SETTINGS" />
 
     <application
         android:allowBackup="true"
+        android:fullBackupContent="@xml/backup_descriptor"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@style/FUTheme"
-        android:fullBackupContent="@xml/backup_descriptor">
+        android:theme="@style/FUTheme">
         <activity
             android:name=".MainActivity"
             android:label="@string/app_name">
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <action android:name="android.intent.action.MAIN" />
+
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
         <provider
             android:name="androidx.core.content.FileProvider"
             android:authorities="${applicationId}.my.provider"
@@ -31,8 +49,39 @@
             android:grantUriPermissions="true">
             <meta-data
                 android:name="android.support.FILE_PROVIDER_PATHS"
-                android:resource="@xml/provider_paths"/>
+                android:resource="@xml/provider_paths" />
         </provider>
+        <provider
+            android:authorities="de.sebse.fuplanner.contentprovider.kvv.modules"
+            android:name="de.sebse.fuplanner.services.kvv.sync.KVVContentProvider"
+            android:exported="false"
+            android:syncable="true">
+
+        </provider>
+
+        <activity
+            android:name=".services.fulogin.FUAuthenticatorActivity"
+            android:label="@string/title_activity_fuauthenticator" />
+        <service android:name=".services.fulogin.FUAuthenticatorService">
+            <intent-filter>
+                <action android:name="android.accounts.AccountAuthenticator" />
+            </intent-filter>
+            <meta-data android:name="android.accounts.AccountAuthenticator"
+                android:resource="@xml/authenticator" />
+        </service>
+        <service
+            android:name=".services.kvv.sync.KVVSyncService"
+            android:label="@string/kvv_sync"
+            android:exported="false">
+            <intent-filter>
+                <action android:name="android.content.SyncAdapter" />
+            </intent-filter>
+            <meta-data
+                android:name="android.content.SyncAdapter"
+                android:resource="@xml/syncadapter_kvv" />
+        </service>
+
+
     </application>
 
 </manifest>

app/src/main/java/de/sebse/fuplanner/MainActivity.java

@@ -1,5 +1,6 @@
 package de.sebse.fuplanner;
 
+import android.accounts.AccountManager;
 import android.content.Intent;
 import android.os.Bundle;
 import android.view.Menu;
@@ -11,8 +12,11 @@ import android.widget.Toast;
 import com.android.volley.NetworkResponse;
 import com.google.android.material.navigation.NavigationView;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.HashMap;
 import java.util.Iterator;
+import java.util.Locale;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.StringRes;
@@ -25,31 +29,33 @@ import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
 import de.sebse.fuplanner.fragments.CanteensFragment;
-import de.sebse.fuplanner.fragments.LoginFragment;
 import de.sebse.fuplanner.fragments.ModulesFragment;
+import de.sebse.fuplanner.fragments.NewsFragment;
 import de.sebse.fuplanner.fragments.PrefsFragment;
 import de.sebse.fuplanner.fragments.ScheduleFragment;
 import de.sebse.fuplanner.fragments.StartupFragment;
 import de.sebse.fuplanner.fragments.canteen.DaySwitcherFragment;
 import de.sebse.fuplanner.fragments.moddetails.ModDetailFragment;
-import de.sebse.fuplanner.services.Canteen.CanteenBrowser;
-import de.sebse.fuplanner.services.Canteen.types.Canteen;
-import de.sebse.fuplanner.services.GoogleAuth.Credentials;
-import de.sebse.fuplanner.services.GoogleAuth.GoogleAuth;
-import de.sebse.fuplanner.services.KVV.KVV;
-import de.sebse.fuplanner.services.KVV.KVVListener;
-import de.sebse.fuplanner.services.KVV.types.LoginToken;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.canteen.CanteenBrowser;
+import de.sebse.fuplanner.services.canteen.types.Canteen;
+import de.sebse.fuplanner.services.canteen.types.CanteenListener;
+import de.sebse.fuplanner.services.kvv.KVV;
+import de.sebse.fuplanner.services.kvv.KVVListener;
+import de.sebse.fuplanner.services.kvv.types.LoginToken;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.services.news.NewsManager;
+import de.sebse.fuplanner.services.fulogin.AccountGeneral;
+import de.sebse.fuplanner.tools.CustomAccountManager;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.NewAsyncQueue;
+import de.sebse.fuplanner.tools.Preferences;
+import de.sebse.fuplanner.tools.Regex;
 import de.sebse.fuplanner.tools.RequestPermissionsResultListener;
 import de.sebse.fuplanner.tools.logging.Logger;
-import de.sebse.fuplanner.tools.network.NetworkCallback;
-import de.sebse.fuplanner.tools.network.NetworkError;
-import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
+import de.sebse.fuplanner.tools.types.News;
 
 public class MainActivity extends AppCompatActivity
-        implements MainActivityListener, KVVListener,
+        implements MainActivityListener, KVVListener, CanteenListener,
         NavigationView.OnNavigationItemSelectedListener,
         ModulesFragment.OnModulesFragmentInteractionListener,
         CanteensFragment.OnCanteensFragmentInteractionListener {
@@ -58,31 +64,37 @@ public class MainActivity extends AppCompatActivity
     private static final int FRAGMENT_STARTUP = 0;
     private static final int FRAGMENT_MODULES = 1;
     private static final int FRAGMENT_MODULES_DETAILS = 2;
-    private static final int FRAGMENT_LOGIN = 3;
     private static final int FRAGMENT_SCHEDULE = 4;
     private static final int FRAGMENT_CANTEENS = 5;
     private static final int FRAGMENT_CANTEENS_DETAILS = 6;
     private static final int FRAGMENT_PREFERENCES = 7;
+    private static final int FRAGMENT_NEWS = 8;
 
     private static final String ARG_FRAGMENT_PAGE = "fragment_page";
     private static final String ARG_FRAGMENT_STATUS = "fragment_status";
+    private static final int DOUBLE_CLICK_TO_EXIT_MILLIS = 2000;
 
     private FragmentManager mFragmentManager;
-    private GoogleAuth mGoogleAuth;
     private KVV mKVV;
+    private NewsManager mNewsManager;
+    private CanteenBrowser mCanteenBrowser;
     private final Logger log = new Logger(this);
     private NavigationView mNavigationView;
 
-    private int fragmentPage = FRAGMENT_NONE;
-    private String fragmentData = "";
-    private CanteenBrowser mCanteenBrowser;
-    private HashMap<String, RequestPermissionsResultListener> permissionListeners = new HashMap<>();
-    private boolean mOfflineBanner;
-    private NewAsyncQueue mQueue = new NewAsyncQueue();
+    private int mFragmentPage = FRAGMENT_NONE;
+    @NotNull
+    private String mFragmentData = "";
+    private final HashMap<String, RequestPermissionsResultListener> permissionListeners = new HashMap<>();
+    private final NewAsyncQueue mQueue = new NewAsyncQueue();
+    private long mDoubleBackToExitPressedOnce = 0;
+    private CustomAccountManager mAccountManager;
+    private boolean isPaused = false;
+    private boolean isLoggedInBeforePause = false;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        mAccountManager = new CustomAccountManager(AccountManager.get(this), () -> MainActivity.this);
         int desiredPage = getDefaultFragmentAfterLogin();
         String desiredData = "";
         if (savedInstanceState != null) {
@@ -104,28 +116,91 @@ public class MainActivity extends AppCompatActivity
         mNavigationView.setNavigationItemSelectedListener(this);
         mFragmentManager = getSupportFragmentManager();
 
-        if (!getKVV().account().restoreOnlineLogin()) {
-            desiredPage = FRAGMENT_LOGIN;
+        //if (mAccountManager.getAccountsByType(AccountGeneral.ACCOUNT_TYPE).length == 0) {
+        if (!mAccountManager.hasAccounts(AccountGeneral.ACCOUNT_TYPE)) {
+            desiredPage = getDefaultFragmentAfterLogout();
             desiredData = "";
+            mAccountManager.getTokenByType(AccountGeneral.ACCOUNT_TYPE, AccountGeneral.AUTHTOKEN_TYPE_KVV, null);
+            updateNavigation();
+            changeFragment(desiredPage, desiredData);
+        } else {
+            updateNavigation();
+            changeFragment(FRAGMENT_STARTUP);
+            int targetPage = desiredPage;
+            String targetData = desiredData;
+            getKVV().account().restoreOnlineLogin(isRestored -> {
+                updateNavigation();
+                if (isRestored)
+                    changeFragment(targetPage, targetData);
+                else
+                    changeFragment(getDefaultFragmentAfterLogout());
+            });
         }
-        updateNavigation();
-        changeFragment(desiredPage, desiredData);
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        isPaused = true;
+        isLoggedInBeforePause = getKVV().account().isLoggedIn();
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        if (isPaused) {
+            getKVV().account().restoreOnlineLogin(isRestored -> {
+                updateNavigation();
+                if (isRestored && !isLoggedInBeforePause)
+                    changeFragment(getDefaultFragmentAfterLogin());
+                else if (!isRestored && isLoggedInBeforePause) {
+                    getKVV().account().logout(false);
+                    changeFragment(getDefaultFragmentAfterLogout());
+                }
+            });
+        }
+        isPaused = false;
     }
 
     @Override
     public void onBackPressed() {
+        if (mDoubleBackToExitPressedOnce + DOUBLE_CLICK_TO_EXIT_MILLIS > System.currentTimeMillis()) {
+            super.onBackPressed();
+            return;
+        }
+
         DrawerLayout drawer = findViewById(R.id.drawer_layout);
         if (drawer.isDrawerOpen(GravityCompat.START)) {
             drawer.closeDrawer(GravityCompat.START);
         } else {
-            super.onBackPressed();
+            if (mFragmentPage == FRAGMENT_MODULES_DETAILS) {
+                ModDetailFragment fragment = (ModDetailFragment) mFragmentManager.findFragmentByTag(String.valueOf(FRAGMENT_MODULES_DETAILS));
+                if (fragment != null && fragment.isVisible() && Regex.has("\\.[1-9][0-9]*", fragment.getData())) {
+                    fragment.gotoFragmentPart(0, -1);
+                } else {
+                    changeFragment(FRAGMENT_MODULES);
+                }
+            } else if (mFragmentPage == FRAGMENT_CANTEENS_DETAILS) {
+                DaySwitcherFragment fragment = (DaySwitcherFragment) mFragmentManager.findFragmentByTag(String.valueOf(FRAGMENT_CANTEENS_DETAILS));
+                if (fragment != null && fragment.isVisible() && Regex.has("\\.[1-9][0-9]*", fragment.getData())) {
+                    fragment.gotoFragmentPart(0);
+                } else {
+                    changeFragment(FRAGMENT_CANTEENS);
+                }
+            } else if (getKVV().account().isLoggedIn() && mFragmentPage != getDefaultFragmentAfterLogin()) {
+                changeFragment(getDefaultFragmentAfterLogin());
+            } else {
+                mDoubleBackToExitPressedOnce = System.currentTimeMillis();
+                showToast(R.string.back_to_exit);
+                //getTokenForAccountCreateIfNeeded(AccountGeneral.ACCOUNT_TYPE, AccountGeneral.AUTHTOKEN_TYPE_KVV);
+            }
         }
     }
 
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         // Inflate the menu; this adds items to the action bar if it is present.
-        if (fragmentPage == FRAGMENT_SCHEDULE) {
+        if (mFragmentPage == FRAGMENT_SCHEDULE) {
             getMenuInflater().inflate(R.menu.options_schedule, menu);
             return true;
         }
@@ -171,6 +246,9 @@ public class MainActivity extends AppCompatActivity
             case R.id.nav_canteens:
                 changeFragment(FRAGMENT_CANTEENS);
                 break;
+            case R.id.nav_news:
+                changeFragment(FRAGMENT_NEWS);
+                break;
             case R.id.nav_settings:
                 changeFragment(FRAGMENT_PREFERENCES);
                 break;
@@ -184,11 +262,6 @@ public class MainActivity extends AppCompatActivity
             case R.id.nav_logout:
                 getKVV().account().logout(true);
                 getKVV().modules().list().delete();
-                this.getGoogleAuth().getLoginState(credentials -> {
-                    if (credentials != null) {
-                        this.getGoogleAuth().deleteLoginState(credentials.getUsername(), credentials.getPassword());
-                    }
-                });
                 break;
 
         }
@@ -204,21 +277,17 @@ public class MainActivity extends AppCompatActivity
         return true;
     }
 
-    @Override
-    public void onActivityResult(int requestCode, int resultCode, Intent data) {
-        super.onActivityResult(requestCode, resultCode, data);
-        this.getGoogleAuth().onActivityResult(requestCode, resultCode, data);
-    }
-
     @Override
     protected void onSaveInstanceState(Bundle savedInstanceState) {
-        if (fragmentPage != FRAGMENT_STARTUP && fragmentPage != FRAGMENT_NONE && fragmentPage != FRAGMENT_LOGIN) {
-            Fragment fragment = mFragmentManager.findFragmentByTag(String.valueOf(fragmentPage));
-            savedInstanceState.putInt(ARG_FRAGMENT_PAGE, fragmentPage);
+        if (mFragmentPage != FRAGMENT_STARTUP && mFragmentPage != FRAGMENT_NONE) {
+            Fragment fragment = mFragmentManager.findFragmentByTag(String.valueOf(mFragmentPage));
+            savedInstanceState.putInt(ARG_FRAGMENT_PAGE, mFragmentPage);
             if (fragment instanceof ModDetailFragment) {
                 savedInstanceState.putString(ARG_FRAGMENT_STATUS, ((ModDetailFragment) fragment).getData());
+            } else if (fragment instanceof DaySwitcherFragment) {
+                savedInstanceState.putString(ARG_FRAGMENT_STATUS, ((DaySwitcherFragment) fragment).getData());
             } else {
-                savedInstanceState.putString(ARG_FRAGMENT_STATUS, fragmentData);
+                savedInstanceState.putString(ARG_FRAGMENT_STATUS, mFragmentData);
             }
         }
         super.onSaveInstanceState(savedInstanceState);
@@ -235,21 +304,13 @@ public class MainActivity extends AppCompatActivity
     /* --------------------------------------------*/
     /* --------------------------------------------*/
 
-    public GoogleAuth getGoogleAuth() {
-        if (this.mGoogleAuth == null) {
-            this.mGoogleAuth = new GoogleAuth(this);
+    public NewsManager getNewsManager() {
+        if (this.mNewsManager == null) {
+            this.mNewsManager = new NewsManager(this);
         }
-        return this.mGoogleAuth;
+        return this.mNewsManager;
     }
 
-    /*@Deprecated
-    public de.sebse.fuplanner.services.KVV.KVV getKVV() {
-        if (this.mKVV == null) {
-            this.mKVV = new de.sebse.fuplanner.services.KVV.KVV(this);
-        }
-        return this.mKVV;
-    }*/
-
     public KVV getKVV() {
         if (this.mKVV == null) {
             this.mKVV = new KVV(this, this);
@@ -268,15 +329,18 @@ public class MainActivity extends AppCompatActivity
         return FRAGMENT_MODULES;
     }
 
-    private void toLogoutState() {
-        setOfflineBanner(false);
-        setRefreshFailedBanner(false);
-        updateNavigation();
-        changeFragment(FRAGMENT_LOGIN);
+    private int getDefaultFragmentAfterLogout() {
+        return FRAGMENT_CANTEENS;
     }
 
-    private void toLoginState(String fullName, String email, int newFragment, boolean onlineMode) {
-        setOfflineBanner(!onlineMode);
+    private void toLogoutState() {
+        setRefreshFailedBanner(false);
+        updateNavigation();
+        changeFragment(getDefaultFragmentAfterLogout());
+        mAccountManager.getTokenByType(AccountGeneral.ACCOUNT_TYPE, AccountGeneral.AUTHTOKEN_TYPE_KVV, null);
+    }
+
+    private void toLoginState(String fullName, String email, int newFragment) {
         updateNavigation();
 
         View header = mNavigationView.getHeaderView(0);
@@ -307,18 +371,23 @@ public class MainActivity extends AppCompatActivity
             case FRAGMENT_MODULES:
                 fragment = ModulesFragment.newInstance();
                 break;
-            case FRAGMENT_LOGIN:
+            /*case FRAGMENT_LOGIN:
                 fragment = LoginFragment.newInstance();
-                break;
+                break;*/
             case FRAGMENT_SCHEDULE:
                 fragment = ScheduleFragment.newInstance();
                 break;
             case FRAGMENT_CANTEENS_DETAILS:
-                fragment = DaySwitcherFragment.newInstance(Integer.parseInt(newData));
+                fragment = DaySwitcherFragment.newInstance(newData);
                 break;
             case FRAGMENT_CANTEENS:
                 fragment = CanteensFragment.newInstance();
                 break;
+            case FRAGMENT_NEWS:
+                Preferences.setLong(this, R.string.pref_last_visited_news, System.currentTimeMillis());
+                updateNavigation();
+                fragment = NewsFragment.newInstance();
+                break;
             case FRAGMENT_PREFERENCES:
                 fragment = PrefsFragment.newInstance();
                 break;
@@ -337,69 +406,72 @@ public class MainActivity extends AppCompatActivity
             findViewById(R.id.app_bar_include).setVisibility(View.VISIBLE);
         }
 
-        this.fragmentPage = newFragment;
-        this.fragmentData = newData;
+        this.mFragmentPage = newFragment;
+        this.mFragmentData = newData;
 
         invalidateOptionsMenu();
     }
 
-    private void setOfflineBanner(boolean visible) {
-        View offline_header = findViewById(R.id.offline_msg);
-        offline_header.setVisibility(visible ? View.VISIBLE : View.GONE);
-        mOfflineBanner = visible;
-    }
-
     private void setRefreshFailedBanner(boolean refreshFailed) {
         View viewNoConnection = findViewById(R.id.no_connection_msg);
-        if (!mOfflineBanner && refreshFailed)
+        if (refreshFailed)
             viewNoConnection.setVisibility(View.VISIBLE);
         else
             viewNoConnection.setVisibility(View.GONE);
     }
 
     private void setNavigationSelection() {
-        MenuItem item;
-        switch (fragmentPage) {
+        MenuItem item = null;
+        switch (mFragmentPage) {
             case FRAGMENT_MODULES_DETAILS:
-                getKVV().modules().list().find(fragmentData, success -> {
+                getKVV().modules().list().find(mFragmentData, success -> {
                     int size = mNavigationView.getMenu().size();
                     //noinspection ConstantConditions
                     String title = success == null ? null : success.title;
                     for (int k = 0; k < size; k++) {
-                        mNavigationView.getMenu().getItem(k).setChecked(mNavigationView.getMenu().getItem(k).getTitle().equals(title));
+                        MenuItem menuItem = mNavigationView.getMenu().getItem(k);
+                        if (menuItem.getTitle().equals(title)) {
+                            menuItem.setChecked(true);
+                            break;
+                        }
                     }
                 }, log::e);
-                break;
+                return;
             case FRAGMENT_MODULES:
                 item = mNavigationView.getMenu().findItem(R.id.nav_modules);
-                if (item != null)
-                    item.setChecked(true);
                 break;
             case FRAGMENT_SCHEDULE:
                 item = mNavigationView.getMenu().findItem(R.id.nav_schedule);
-                if (item != null)
-                    item.setChecked(true);
                 break;
             case FRAGMENT_CANTEENS_DETAILS:
                 getCanteenBrowser().getCanteens(success -> {
                     int size = mNavigationView.getMenu().size();
-                    Canteen canteen = success.getCanteen(Integer.parseInt(fragmentData));
+                    Canteen canteen = success.getCanteen(Integer.parseInt(mFragmentData));
                     //noinspection ConstantConditions
                     String title = canteen == null ? null : canteen.getName();
                     for (int k = 0; k < size; k++) {
-                        mNavigationView.getMenu().getItem(k).setChecked(mNavigationView.getMenu().getItem(k).getTitle().equals(title));
+                        MenuItem menuItem = mNavigationView.getMenu().getItem(k);
+                        if (menuItem.getTitle().equals(title)) {
+                            menuItem.setChecked(true);
+                            break;
+                        }
                     }
                 }, log::e);
-                break;
+                return;
             case FRAGMENT_CANTEENS:
-                mNavigationView.getMenu().findItem(R.id.nav_canteens).setChecked(true);
+                item = mNavigationView.getMenu().findItem(R.id.nav_canteens);
+                break;
+            case FRAGMENT_NEWS:
+                item = mNavigationView.getMenu().findItem(R.id.nav_news);
                 break;
             case FRAGMENT_PREFERENCES:
-                mNavigationView.getMenu().findItem(R.id.nav_settings).setChecked(true);
+                item = mNavigationView.getMenu().findItem(R.id.nav_settings);
                 break;
             default:  // FRAGMENT_STARTUP / FRAGMENT_LOGIN
                 break;
         }
+        if (item != null)
+            item.setChecked(true);
     }
 
     private void setNavigationHeader(boolean isLoggedIn) {
@@ -417,12 +489,12 @@ public class MainActivity extends AppCompatActivity
                 if (drawer.isDrawerOpen(GravityCompat.START)) {
                     drawer.closeDrawer(GravityCompat.START);
                 }
-                changeFragment(FRAGMENT_LOGIN);
+                mAccountManager.getTokenByType(AccountGeneral.ACCOUNT_TYPE, AccountGeneral.AUTHTOKEN_TYPE_KVV, null);
             });
     }
 
     private void afterAnyMenuInflate(boolean isLoggedIn, Runnable done) {
-        int MAX_COUNT = isLoggedIn ? 2 : 1;
+        int MAX_COUNT = isLoggedIn ? 3 : 2;
         final int[] count = {0};
         if (isLoggedIn) {
             getKVV().modules().list().recv(success -> {
@@ -437,9 +509,9 @@ public class MainActivity extends AppCompatActivity
                     i++;
                 }
                 if (++count[0] == MAX_COUNT) done.run();
-            }, msg -> {
+            }, error -> {
                 if (++count[0] == MAX_COUNT) done.run();
-                log.e(msg);
+                log.e(error);
             });
         }
         getCanteenBrowser().getCanteens(success -> {
@@ -453,9 +525,28 @@ public class MainActivity extends AppCompatActivity
                 i++;
             }
             if (++count[0] == MAX_COUNT) done.run();
-        }, msg -> {
+        }, error -> {
             if (++count[0] == MAX_COUNT) done.run();
-            log.e(msg);
+            log.e(error);
+        });
+        getNewsManager().recv(success -> {
+            long lastVisited = Preferences.getLong(this, R.string.pref_last_visited_news);
+            int i = 0;
+            for (News news: success) {
+                if (news.getDate() > lastVisited) i++;
+            }
+            if (i > 0) {
+                MenuItem menuItem = mNavigationView.getMenu().findItem(R.id.nav_news);
+                menuItem.setIcon(R.drawable.ic_sms_failed);
+                View view = View.inflate(this, R.layout.action_icon_number, null);
+                TextView v = view.findViewById(R.id.number);
+                v.setText(String.format(Locale.getDefault(), "%d", i));
+                menuItem.setActionView(view);
+            }
+            if (++count[0] == MAX_COUNT) done.run();
+        }, error -> {
+            if (++count[0] == MAX_COUNT) done.run();
+            log.e(error);
         });
     }
 
@@ -483,14 +574,19 @@ public class MainActivity extends AppCompatActivity
 
 
 
+
+
+
     @Override
     public void onModulesFragmentInteraction(final String itemID) {
         changeFragment(FRAGMENT_MODULES_DETAILS, itemID);
+        setNavigationSelection();
     }
 
     @Override
     public void onCanteensFragmentInteraction(final int itemID) {
         changeFragment(FRAGMENT_CANTEENS_DETAILS, String.valueOf(itemID));
+        setNavigationSelection();
     }
 
     @Override
@@ -504,7 +600,7 @@ public class MainActivity extends AppCompatActivity
     }
 
     @Override
-    public void onRefreshCompleted(boolean isFailed) {
+    public void onCanteenRefreshCompleted(boolean isFailed) {
         setRefreshFailedBanner(isFailed);
     }
 
@@ -537,20 +633,10 @@ public class MainActivity extends AppCompatActivity
 
 
 
-    @Override
-    public void getCredentials(NetworkCallback<Credentials> callback, NetworkErrorCallback error) {
-        getGoogleAuth().getLoginState(credentials -> {
-            if (credentials == null || credentials.getUsername() == null || credentials.getPassword() == null) {
-                error.onError(new NetworkError(200100, 403, "No Google Login available!"));
-            } else {
-                callback.onResponse(credentials);
-            }
-        });
-    }
 
     @Override
-    public void onLogin(LoginToken token, boolean enteringOnlineMode) {
-        toLoginState(token.getFullName(), token.getEmail(), getDefaultFragmentAfterLogin(), enteringOnlineMode);
+    public void onLogin(LoginToken token) {
+        toLoginState(token.getFullName(), token.getEmail(), getDefaultFragmentAfterLogin());
     }
 
     @Override
@@ -567,4 +653,9 @@ public class MainActivity extends AppCompatActivity
     public void onKVVNetworkResponse(NetworkResponse error) {
         setRefreshFailedBanner(error != null);
     }
+
+    @Override
+    public CustomAccountManager getAccountManager() {
+        return mAccountManager;
+    }
 }

app/src/main/java/de/sebse/fuplanner/fragments/CanteensAdapter.java

@@ -8,12 +8,12 @@ import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.RecyclerView;
 import de.sebse.fuplanner.R;
 import de.sebse.fuplanner.fragments.CanteensFragment.OnCanteensFragmentInteractionListener;
-import de.sebse.fuplanner.services.Canteen.types.Canteen;
-import de.sebse.fuplanner.services.Canteen.types.Canteens;
+import de.sebse.fuplanner.services.canteen.types.Canteen;
+import de.sebse.fuplanner.services.canteen.types.Canteens;
 import de.sebse.fuplanner.tools.ui.ItemViewHolder;
 
 /**
- * {@link RecyclerView.Adapter} that can display a {@link Modules.Module} and makes a call to the
+ * {@link RecyclerView.Adapter} that can display a {@link Canteen} and makes a call to the
  * specified {@link OnCanteensFragmentInteractionListener}.
  */
 class CanteensAdapter extends RecyclerView.Adapter<ItemViewHolder> {

app/src/main/java/de/sebse/fuplanner/fragments/CanteensFragment.java

@@ -13,7 +13,7 @@ import androidx.recyclerview.widget.RecyclerView;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import de.sebse.fuplanner.MainActivity;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.Canteen.CanteenBrowser;
+import de.sebse.fuplanner.services.canteen.CanteenBrowser;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.logging.Logger;
 
@@ -48,7 +48,7 @@ public class CanteensFragment extends Fragment {
     public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
 
-        View view = inflater.inflate(R.layout.fragment_modules_list, container, false);
+        View view = inflater.inflate(R.layout.fragment_recycler_view, container, false);
         // Set the adapter
         Context context = view.getContext();
         RecyclerView recyclerView = view.findViewById(R.id.list);

app/src/main/java/de/sebse/fuplanner/fragments/LoginFragment.java

@@ -1,112 +0,0 @@
-package de.sebse.fuplanner.fragments;
-
-import android.app.ProgressDialog;
-import android.content.Context;
-import android.os.Bundle;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.Button;
-import android.widget.EditText;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.fragment.app.Fragment;
-import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.tools.MainActivityListener;
-import de.sebse.fuplanner.tools.logging.Logger;
-
-/**
- * A simple {@link Fragment} subclass.
- * Use the {@link LoginFragment#newInstance} factory method to
- * create an instance of this fragment.
- */
-public class LoginFragment extends Fragment {
-    private final Logger log = new Logger(this);
-    @Nullable private MainActivityListener mActivityListener;
-
-    public LoginFragment() {
-        // Required empty public constructor
-    }
-
-    /**
-     * Use this factory method to create a new instance of
-     * this fragment using the provided parameters.
-     *
-     * @return A new instance of fragment LoginFragment.
-     */
-    public static LoginFragment newInstance() {
-        LoginFragment fragment = new LoginFragment();
-        Bundle args = new Bundle();
-        fragment.setArguments(args);
-        return fragment;
-    }
-
-    @Override
-    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
-                             Bundle savedInstanceState) {
-        // Inflate the layout for this fragment
-        View v = inflater.inflate(R.layout.fragment_login, container, false);
-        if (mActivityListener != null && mActivityListener.getKVV().account().isOfflineStoredAvailable()) {
-            Button offline_btn = v.findViewById(R.id.btn_offline);
-            offline_btn.setVisibility(View.VISIBLE);
-            offline_btn.setText(v.getResources().getString(R.string.enter_offline_mode, mActivityListener.getKVV().modules().list().getUsername()));
-            offline_btn.setOnClickListener(v1 -> mActivityListener.getKVV().account().doOfflineLogin());
-        }
-
-        View btn_login = v.findViewById(R.id.btn_login);
-        btn_login.setOnClickListener(view -> {
-            final ProgressDialog progressDialog = new ProgressDialog(LoginFragment.this.getContext(),
-                    R.style.FUTheme_Dialog);
-            progressDialog.setIndeterminate(true);
-            progressDialog.setMessage("Authenticating...");
-            progressDialog.show();
-
-            EditText input_usr = ((View) view.getParent()).findViewById(R.id.input_username);
-            EditText input_pwd = ((View) view.getParent()).findViewById(R.id.input_password);
-
-            String username = input_usr.getText().toString();
-            String password = input_pwd.getText().toString();
-
-            mActivityListener.getKVV().account().doOnlineLogin(username, password, success -> {
-                progressDialog.dismiss();
-                mActivityListener.getGoogleAuth().setLoginState(username, password);
-                input_usr.setError(null);
-                input_pwd.setError(null);
-            }, error -> {
-                progressDialog.dismiss();
-                // Invalid password
-                if (mActivityListener != null) {
-                    if (error.getCode() == 100131) {
-                        mActivityListener.showToast(R.string.invalid_credentials);
-                        input_usr.setError(input_usr.getResources().getString(R.string.invalid_credentials));
-                        input_pwd.setError(input_pwd.getResources().getString(R.string.invalid_credentials));
-                    } else {
-                        mActivityListener.showToast(v.getResources().getString(R.string.error_occurred_code, error.getCode()));
-                    }
-                }
-                log.e("Error on KVV login!", error);
-            });
-        });
-
-        return v;
-    }
-
-
-
-    @Override
-    public void onAttach(Context context) {
-        super.onAttach(context);
-        if (context instanceof MainActivityListener) {
-            mActivityListener = (MainActivityListener) context;
-            mActivityListener.onTitleTextChange(R.string.log_in);
-        } else
-            throw new RuntimeException(context.toString() + " must implement MainActivityListener");
-    }
-
-    @Override
-    public void onDetach() {
-        super.onDetach();
-        mActivityListener = null;
-    }
-}

app/src/main/java/de/sebse/fuplanner/fragments/ModulesAdapter.java

@@ -11,9 +11,9 @@ import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.RecyclerView;
 import de.sebse.fuplanner.R;
 import de.sebse.fuplanner.fragments.ModulesFragment.OnModulesFragmentInteractionListener;
-import de.sebse.fuplanner.services.KVV.types.Lecturer;
-import de.sebse.fuplanner.services.KVV.types.Modules;
-import de.sebse.fuplanner.services.KVV.types.Semester;
+import de.sebse.fuplanner.services.kvv.types.Lecturer;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Semester;
 import de.sebse.fuplanner.tools.ui.CustomViewHolder;
 import de.sebse.fuplanner.tools.ui.ItemViewHolder;
 import de.sebse.fuplanner.tools.ui.StringViewHolder;

app/src/main/java/de/sebse/fuplanner/fragments/ModulesFragment.java

@@ -47,7 +47,7 @@ public class ModulesFragment extends Fragment {
     public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
 
-        View view = inflater.inflate(R.layout.fragment_modules_list, container, false);
+        View view = inflater.inflate(R.layout.fragment_recycler_view, container, false);
         // Set the adapter
         Context context = view.getContext();
         RecyclerView recyclerView = view.findViewById(R.id.list);

app/src/main/java/de/sebse/fuplanner/fragments/NewsAdapter.java

@@ -0,0 +1,61 @@
+package de.sebse.fuplanner.fragments;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+import de.sebse.fuplanner.R;
+import de.sebse.fuplanner.fragments.ModulesFragment.OnModulesFragmentInteractionListener;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.tools.UtilsDate;
+import de.sebse.fuplanner.tools.types.News;
+import de.sebse.fuplanner.tools.types.NewsList;
+import de.sebse.fuplanner.tools.ui.NewsViewHolder;
+
+/**
+ * {@link RecyclerView.Adapter} that can display a {@link Modules.Module} and makes a call to the
+ * specified {@link OnModulesFragmentInteractionListener}.
+ */
+class NewsAdapter extends RecyclerView.Adapter<NewsViewHolder> {
+
+
+    private NewsList mValues;
+
+    NewsAdapter() {
+        mValues = null;
+    }
+
+    public void setNews(NewsList news) {
+        mValues = news;
+        this.notifyDataSetChanged();
+    }
+
+    @NonNull
+    @Override
+    public NewsViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        View view = LayoutInflater.from(parent.getContext())
+                    .inflate(R.layout.list_news_item, parent, false);
+            return new NewsViewHolder(view);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull NewsViewHolder holder, int position) {
+        News news = mValues.getPast(position);
+        holder.mHeader.setText(news.getTitle());
+        switch (news.getCategory()) {
+            case News.CATEGORY_UPDATE:
+                holder.mSubLeft.setText(R.string.update_news);
+            case News.CATEGORY_TRICKS:
+                holder.mSubLeft.setText(R.string.tricks);
+        }
+        holder.mSubRight.setText(UtilsDate.getModifiedDate(news.getDate()));
+        holder.mText.setText(news.getText());
+    }
+
+    @Override
+    public int getItemCount() {
+        return mValues != null ? mValues.sizePast() : 0;
+    }
+}

app/src/main/java/de/sebse/fuplanner/fragments/NewsFragment.java

@@ -0,0 +1,97 @@
+package de.sebse.fuplanner.fragments;
+
+
+import android.content.Context;
+import android.os.Bundle;
+
+import androidx.annotation.NonNull;
+import androidx.fragment.app.Fragment;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+import de.sebse.fuplanner.R;
+import de.sebse.fuplanner.tools.MainActivityListener;
+import de.sebse.fuplanner.tools.logging.Logger;
+import de.sebse.fuplanner.tools.types.NewsList;
+
+/**
+ * A simple {@link Fragment} subclass.
+ * Use the {@link NewsFragment#newInstance} factory method to
+ * create an instance of this fragment.
+ */
+public class NewsFragment extends Fragment {
+    private Logger log = new Logger(this);
+    private MainActivityListener mListener;
+    private NewsAdapter mAdapter;
+    private NewsList dates = new NewsList();
+    // TODO: Rename parameter arguments, choose names that match
+    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
+
+    // TODO: Rename and change types of parameters
+
+
+    public NewsFragment() {
+        // Required empty public constructor
+    }
+
+    /**
+     * Use this factory method to create a new instance of
+     * this fragment using the provided parameters.
+     *
+     * @return A new instance of fragment NewsFragment.
+     */
+    // TODO: Rename and change types and number of parameters
+    public static NewsFragment newInstance() {
+        NewsFragment fragment = new NewsFragment();
+        Bundle args = new Bundle();
+        fragment.setArguments(args);
+        return fragment;
+    }
+
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        if (context instanceof MainActivityListener) {
+            mListener = (MainActivityListener) context;
+            mListener.onTitleTextChange(R.string.news);
+        }
+        else
+            throw new RuntimeException(context.toString() + " must implement MainActivityListener");
+        refresh(false);
+    }
+
+    @Override
+    public void onDetach() {
+        super.onDetach();
+        mListener = null;
+    }
+
+    @Override
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
+                             Bundle savedInstanceState) {
+        View view = inflater.inflate(R.layout.fragment_recycler_norefresh, container, false);
+        // Set the adapter
+        Context context = view.getContext();
+        RecyclerView recyclerView = view.findViewById(R.id.list);
+        recyclerView.setLayoutManager(new LinearLayoutManager(context));
+        mAdapter = new NewsAdapter();
+        recyclerView.setAdapter(mAdapter);
+        refresh(false);
+
+        return view;
+    }
+
+    private void refresh(boolean forceRefresh) {
+        if (mListener == null)
+            return;
+        mListener.getNewsManager().recv(success -> {
+            if (mAdapter != null)
+                mAdapter.setNews(success);
+        }, log::e, forceRefresh);
+    }
+
+}

app/src/main/java/de/sebse/fuplanner/fragments/ScheduleFragment.java

@@ -16,8 +16,8 @@ import java.util.List;
 import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.types.Event;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Event;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.UtilsDate;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.logging.Logger;
@@ -34,7 +34,11 @@ import de.sebse.fuplanner.tools.ui.weekview.WeekViewEvent;
  * create an instance of this fragment.
  *
  */
-public class ScheduleFragment extends Fragment implements MonthLoader.MonthChangeListener, WeekView.ScrollListener, WeekView.DoubleTapListener, WeekView.EventClickListener {
+public class ScheduleFragment extends Fragment implements
+        MonthLoader.MonthChangeListener,
+        WeekView.ScrollListener,
+        WeekView.DoubleTapLeftRightListener,
+        WeekView.EventClickListener {
     private MainActivityListener mListener;
     private WeekView mWeekView;
     private final Logger log = new Logger(this);
@@ -83,7 +87,7 @@ public class ScheduleFragment extends Fragment implements MonthLoader.MonthChang
         mWeekView = v.findViewById(R.id.weekView);
         mWeekView.setMonthChangeListener(this);
         mWeekView.setScrollListener(this);
-        mWeekView.setDoubleTapListener(this);
+        mWeekView.setDoubleTapLeftRightListener(this);
         mWeekView.setOnEventClickListener(this);
         invalidate(false);
         return v;
@@ -150,26 +154,21 @@ public class ScheduleFragment extends Fragment implements MonthLoader.MonthChang
     }
 
     @Override
-    public void onDoubleTapListener(Calendar time) {
+    public void onDoubleTapLeftRightListener(boolean isRight) {
         Calendar firstVisibleDay = mWeekView.getFirstVisibleDay();
-        Calendar c = Calendar.getInstance();
-        c.set(firstVisibleDay.get(Calendar.YEAR), firstVisibleDay.get(Calendar.MONTH), firstVisibleDay.get(Calendar.DAY_OF_MONTH), 0,0 );
-        // Limit when to go a week backwards and when to the next week
-        c.add(Calendar.DATE, 2);
-
         // skip to next week
-        if (c.getTimeInMillis() > time.getTimeInMillis()){
-            firstVisibleDay.add(Calendar.DATE, -1);
-            while (firstVisibleDay.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY) {
-                firstVisibleDay.add(Calendar.DATE, -1);
-            }
-        }
-        else{
+        if (isRight){
             firstVisibleDay.add(Calendar.DATE, 1);
             while (firstVisibleDay.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY) {
                 firstVisibleDay.add(Calendar.DATE, 1);
             }
         }
+        else {
+            firstVisibleDay.add(Calendar.DATE, -1);
+            while (firstVisibleDay.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY) {
+                firstVisibleDay.add(Calendar.DATE, -1);
+            }
+        }
         mWeekView.goToDate(firstVisibleDay);
         onFirstVisibleDayChanged(firstVisibleDay, mWeekView.getLastVisibleDay());
     }

app/src/main/java/de/sebse/fuplanner/fragments/canteen/DaySwitcherAdapter.java

@@ -4,7 +4,7 @@ import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentStatePagerAdapter;
 
-import de.sebse.fuplanner.services.Canteen.types.Canteen;
+import de.sebse.fuplanner.services.canteen.types.Canteen;
 import de.sebse.fuplanner.tools.UtilsDate;
 
 class DaySwitcherAdapter extends FragmentStatePagerAdapter {

app/src/main/java/de/sebse/fuplanner/fragments/canteen/DaySwitcherFragment.java

@@ -11,8 +11,8 @@ import androidx.fragment.app.Fragment;
 import androidx.viewpager.widget.ViewPager;
 import de.sebse.fuplanner.MainActivity;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.Canteen.CanteenBrowser;
-import de.sebse.fuplanner.services.Canteen.types.Canteen;
+import de.sebse.fuplanner.services.canteen.CanteenBrowser;
+import de.sebse.fuplanner.services.canteen.types.Canteen;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.logging.Logger;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
@@ -31,10 +31,12 @@ public class DaySwitcherFragment extends Fragment implements DaySwitcherListener
 
     // Parameters
     private int mCanteenId;
+    private String mPageRestoreRequest = null;
 
     private MainActivityListener mListener;
     private final Logger log = new Logger(this);
     private DaySwitcherAdapter adapterViewPager;
+    private ViewPager mViewPager;
 
     public DaySwitcherFragment() {
         // Required empty public constructor
@@ -47,10 +49,14 @@ public class DaySwitcherFragment extends Fragment implements DaySwitcherListener
      * @param canteenId Canteen id in canteens list.
      * @return A new instance of fragment DaySwitcherFragment.
      */
-    public static Fragment newInstance(int canteenId) {
+    public static Fragment newInstance(String canteenId) {
         DaySwitcherFragment fragment = new DaySwitcherFragment();
         Bundle args = new Bundle();
-        args.putInt(ARG_POSITION, canteenId);
+        if (!canteenId.contains("."))
+            args.putString(ARG_POSITION, canteenId+".0");
+        else
+            args.putString(ARG_POSITION, canteenId);
+
         fragment.setArguments(args);
         return fragment;
     }
@@ -59,7 +65,15 @@ public class DaySwitcherFragment extends Fragment implements DaySwitcherListener
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         if (getArguments() != null) {
-            mCanteenId = getArguments().getInt(ARG_POSITION);
+            String canteenId = getArguments().getString(ARG_POSITION);
+            if (!canteenId.contains(".")) {
+                mCanteenId = Integer.parseInt(canteenId);
+                mPageRestoreRequest = null;
+            } else {
+                String[] split = canteenId.split("\\.", 2);
+                mCanteenId = Integer.parseInt(split[0]);
+                mPageRestoreRequest = split[1];
+            }
         }
         if (mListener != null) {
             mListener.onTitleTextChange(R.string.canteens);
@@ -77,10 +91,10 @@ public class DaySwitcherFragment extends Fragment implements DaySwitcherListener
         // Inflate the layout for this fragment
         View v = inflater.inflate(R.layout.fragment_mod_detail, container, false);
 
-        ViewPager mViewPager = v.findViewById(R.id.vpPager);
+        mViewPager = v.findViewById(R.id.vpPager);
         adapterViewPager = new DaySwitcherAdapter(getChildFragmentManager());
         mViewPager.setAdapter(adapterViewPager);
-
+        applyPageRequest();
         refresh();
 
         return v;
@@ -114,8 +128,10 @@ public class DaySwitcherFragment extends Fragment implements DaySwitcherListener
                 Canteen canteen = canteens.getCanteen(mCanteenId);
                 canteen.cleanUpDays();
                 adapterViewPager.setModule(canteen);
+                applyPageRequest();
                 browser.getCanteen(canteen, success -> {
                     adapterViewPager.setModule();
+                    applyPageRequest();
                     if (callback != null)
                         callback.onResponse(success);
                 }, error -> {
@@ -136,4 +152,20 @@ public class DaySwitcherFragment extends Fragment implements DaySwitcherListener
         refresh(true, callback, errorCallback);
     }
 
+    public void gotoFragmentPart(int part) {
+        mViewPager.setCurrentItem(part, true);
+    }
+
+    public String getData() {
+        return mCanteenId+"."+mViewPager.getCurrentItem();
+    }
+
+    private void applyPageRequest() {
+        if (mPageRestoreRequest != null) {
+            int request = Integer.parseInt(mPageRestoreRequest);
+            mViewPager.setCurrentItem(request);
+            if (request == mViewPager.getCurrentItem())
+                mPageRestoreRequest = null;
+        }
+    }
 }

app/src/main/java/de/sebse/fuplanner/fragments/canteen/DaySwitcherListener.java

@@ -1,6 +1,6 @@
 package de.sebse.fuplanner.fragments.canteen;
 
-import de.sebse.fuplanner.services.Canteen.types.Canteen;
+import de.sebse.fuplanner.services.canteen.types.Canteen;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
 

app/src/main/java/de/sebse/fuplanner/fragments/canteen/MealAdapter.java

@@ -13,19 +13,19 @@ import androidx.annotation.NonNull;
 import androidx.annotation.StringRes;
 import androidx.recyclerview.widget.RecyclerView;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.Canteen.types.Day;
-import de.sebse.fuplanner.services.Canteen.types.Meal;
+import de.sebse.fuplanner.services.canteen.types.Day;
+import de.sebse.fuplanner.services.canteen.types.Meal;
 import de.sebse.fuplanner.tools.Preferences;
 import de.sebse.fuplanner.tools.ui.MealViewHolder;
 import de.sebse.fuplanner.tools.ui.StringViewHolder;
 
 class MealAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
-    private String[] CATEGORY_KEYS = new String[]{"Essen", "Aktionen", "Beilagen", "Desserts", "Salate", "Suppen", "Vorspeisen"};
+    private final String[] CATEGORY_KEYS = new String[]{"Essen", "Aktionen", "Beilagen", "Desserts", "Salate", "Suppen", "Vorspeisen"};
     @StringRes
-    private int[] CATEGORY_VALS = new int[]{R.string.meals, R.string.special_meals, R.string.side_dishes, R.string.desserts, R.string.salads, R.string.soups, R.string.starters};
+    private final int[] CATEGORY_VALS = new int[]{R.string.meals, R.string.special_meals, R.string.side_dishes, R.string.desserts, R.string.salads, R.string.soups, R.string.starters};
     @StringRes
-    private int CATEGORY_OTHER = R.string.others;
-    private ArrayList<Object> matches = new ArrayList<>();
+    private final int CATEGORY_OTHER = R.string.others;
+    private final ArrayList<Object> matches = new ArrayList<>();
 
     private Day mDay = null;
     private final Context mContext;

app/src/main/java/de/sebse/fuplanner/fragments/canteen/MealFragment.java

@@ -13,9 +13,9 @@ import androidx.recyclerview.widget.RecyclerView;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import de.sebse.fuplanner.MainActivity;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.Canteen.CanteenBrowser;
-import de.sebse.fuplanner.services.Canteen.types.Canteen;
-import de.sebse.fuplanner.services.Canteen.types.Day;
+import de.sebse.fuplanner.services.canteen.CanteenBrowser;
+import de.sebse.fuplanner.services.canteen.types.Canteen;
+import de.sebse.fuplanner.services.canteen.types.Day;
 import de.sebse.fuplanner.tools.logging.Logger;
 
 /**

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailAnnounceAdapter.java

@@ -16,9 +16,9 @@ import androidx.annotation.Nullable;
 import androidx.core.content.ContextCompat;
 import androidx.recyclerview.widget.RecyclerView;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.ui.Download;
-import de.sebse.fuplanner.services.KVV.types.Announcement;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.ui.Download;
+import de.sebse.fuplanner.services.kvv.types.Announcement;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.Regex;
 import de.sebse.fuplanner.tools.UtilsDate;
 import de.sebse.fuplanner.tools.logging.Logger;
@@ -29,7 +29,7 @@ class ModDetailAnnounceAdapter extends RecyclerView.Adapter<CustomViewHolder> {
 
     @Nullable private Modules.Module mModule = null;
     private Logger log = new Logger(this);
-    @NonNull private Download.OnDownloadRequestInterface requestInterface;
+    @NonNull private final Download.OnDownloadRequestInterface requestInterface;
 
     ModDetailAnnounceAdapter(@NonNull Download.OnDownloadRequestInterface requestInterface) {
         this.requestInterface = requestInterface;
@@ -40,7 +40,7 @@ class ModDetailAnnounceAdapter extends RecyclerView.Adapter<CustomViewHolder> {
         this.setModule();
     }
 
-    public void setModule() {
+    private void setModule() {
         this.notifyDataSetChanged();
     }
 

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailAnnounceFragment.java

@@ -14,8 +14,8 @@ import androidx.recyclerview.widget.RecyclerView;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import de.sebse.fuplanner.MainActivity;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.ui.Download;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.services.kvv.ui.Download;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.logging.Logger;
 
@@ -84,9 +84,10 @@ public class ModDetailAnnounceFragment extends Fragment implements Download.OnDo
     private void refresh(boolean forceRefresh) {
         if (mListener == null)
             return;
-        mListener.getKVV().modules().announcements().recv(mItemPos, success -> {
-            adapter.setModule(success);
-            swipeLayout.setRefreshing(false);
+        mListener.getKVV().modules().details().recv(mItemPos, pair -> {
+            adapter.setModule(pair.first);
+            if (pair.second)
+                swipeLayout.setRefreshing(false);
         }, error -> {
             swipeLayout.setRefreshing(false);
             log.e(error);
@@ -99,7 +100,7 @@ public class ModDetailAnnounceFragment extends Fragment implements Download.OnDo
             return;
         mListener.getKVV().modules().list().find(mItemPos, (Modules.Module module) -> {
             String folderName = "FU-"+module.title.replaceAll("[:*<>|/\"\\\\]", "-");
-            folderName += "/Assignment";
+            folderName += "/Announcement";
             getDownload().openDownloadDialog(title, url, folderName);
         }, log::e);
     }
@@ -123,7 +124,7 @@ public class ModDetailAnnounceFragment extends Fragment implements Download.OnDo
         }
     }
 
-    Download getDownload() {
+    private Download getDownload() {
         if (download == null)
             download = new Download(this::getContext, () -> (MainActivity) getActivity());
         return download;

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailAssignmentAdapter.java

@@ -16,9 +16,9 @@ import androidx.annotation.Nullable;
 import androidx.core.content.ContextCompat;
 import androidx.recyclerview.widget.RecyclerView;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.ui.Download;
-import de.sebse.fuplanner.services.KVV.types.Assignment;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.ui.Download;
+import de.sebse.fuplanner.services.kvv.types.Assignment;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.Regex;
 import de.sebse.fuplanner.tools.UtilsDate;
 import de.sebse.fuplanner.tools.logging.Logger;
@@ -29,7 +29,7 @@ class ModDetailAssignmentAdapter extends RecyclerView.Adapter<CustomViewHolder>
 
     @Nullable private Modules.Module mModule = null;
     private Logger log = new Logger(this);
-    @NonNull private Download.OnDownloadRequestInterface requestInterface;
+    @NonNull private final Download.OnDownloadRequestInterface requestInterface;
 
     ModDetailAssignmentAdapter(@NonNull Download.OnDownloadRequestInterface requestInterface) {
         this.requestInterface = requestInterface;
@@ -40,7 +40,7 @@ class ModDetailAssignmentAdapter extends RecyclerView.Adapter<CustomViewHolder>
         this.setModule();
     }
 
-    public void setModule() {
+    private void setModule() {
         this.notifyDataSetChanged();
     }
 

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailAssignmentFragment.java

@@ -14,8 +14,8 @@ import androidx.recyclerview.widget.RecyclerView;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import de.sebse.fuplanner.MainActivity;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.ui.Download;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.ui.Download;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.logging.Logger;
 
@@ -84,9 +84,10 @@ public class ModDetailAssignmentFragment extends Fragment implements Download.On
     private void refresh(boolean forceRefresh) {
         if (mListener == null)
             return;
-        mListener.getKVV().modules().assignments().recv(mItemPos, success -> {
-            adapter.setModule(success);
-            swipeLayout.setRefreshing(false);
+        mListener.getKVV().modules().details().recv(mItemPos, pair -> {
+            adapter.setModule(pair.first);
+            if (pair.second)
+                swipeLayout.setRefreshing(false);
         }, error -> {
             swipeLayout.setRefreshing(false);
             log.e(error);
@@ -95,7 +96,6 @@ public class ModDetailAssignmentFragment extends Fragment implements Download.On
 
     @Override
     public void request(String title, String url) {
-        log.d(title, url, mListener);
         if (mListener == null)
             return;
         mListener.getKVV().modules().list().find(mItemPos, (Modules.Module module) -> {
@@ -124,7 +124,7 @@ public class ModDetailAssignmentFragment extends Fragment implements Download.On
         }
     }
 
-    Download getDownload() {
+    private Download getDownload() {
         if (download == null)
             download = new Download(this::getContext, () -> (MainActivity) getActivity());
         return download;

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailEventAdapter.java

@@ -1,6 +1,8 @@
 package de.sebse.fuplanner.fragments.moddetails;
 
+import android.content.Context;
 import android.content.res.Resources;
+import android.util.Pair;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -12,14 +14,15 @@ import java.util.Map;
 import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.RecyclerView;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.types.Event;
-import de.sebse.fuplanner.services.KVV.types.EventList;
-import de.sebse.fuplanner.services.KVV.types.GroupedEvents;
-import de.sebse.fuplanner.services.KVV.types.Modules;
-import de.sebse.fuplanner.tools.Triplet;
+import de.sebse.fuplanner.services.kvv.types.Event;
+import de.sebse.fuplanner.services.kvv.types.EventList;
+import de.sebse.fuplanner.services.kvv.types.GroupedEvents;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.tools.UtilsDate;
 import de.sebse.fuplanner.tools.logging.Logger;
 import de.sebse.fuplanner.tools.ui.CustomViewHolder;
-import de.sebse.fuplanner.tools.ui.ListViewHolder;
+import de.sebse.fuplanner.tools.ui.ItemViewHolder;
+import de.sebse.fuplanner.tools.ui.StringViewHolder;
 
 class ModDetailEventAdapter extends RecyclerView.Adapter<CustomViewHolder> {
     private static final String VALUE_LECTURE = "Class section - Lecture";
@@ -33,9 +36,10 @@ class ModDetailEventAdapter extends RecyclerView.Adapter<CustomViewHolder> {
     private static final int TYPE_NONE = 0;
     private static final int TYPE_GROUPED = 1;
     private static final int TYPE_UNGROUPED = 2;
+    private static final int TYPE_HEADER = 3;
 
     private Modules.Module mValue;
-    private final ArrayList<Triplet<Integer, String, Object>> mPositionalData;
+    private final ArrayList<Pair<Integer, Object>> mPositionalData;
 
     private final Logger log = new Logger(this);
 
@@ -50,7 +54,7 @@ class ModDetailEventAdapter extends RecyclerView.Adapter<CustomViewHolder> {
         this.setModule();
     }
 
-    public void setModule() {
+    private void setModule() {
         LinkedHashMap<String, GroupedEvents> listsGrouped = new LinkedHashMap<>();
         LinkedHashMap<String, EventList> listsUngrouped = new LinkedHashMap<>();
         for (String value : VALUES_GROUPED) listsGrouped.put(value, new GroupedEvents());
@@ -75,15 +79,36 @@ class ModDetailEventAdapter extends RecyclerView.Adapter<CustomViewHolder> {
 
         mPositionalData.clear();
         for (Map.Entry<String, GroupedEvents> value: listsGrouped.entrySet()) {
-            if (value.getValue().getGroups().size() > 0)
-                mPositionalData.add(new Triplet<>(TYPE_GROUPED, value.getKey(), value.getValue()));
+            if (value.getValue().getGroups().size() > 0) {
+                mPositionalData.add(new Pair<>(TYPE_HEADER, value.getKey()));
+                boolean showAsGrouped = true;
+                for (GroupedEvents.Group group : value.getValue().getGroups()) {
+                    if (group.getSkippedDates().size() > 2) {
+                        showAsGrouped = false;
+                        break;
+                    }
+                }
+                if (showAsGrouped) {
+                    for (GroupedEvents.Group group : value.getValue().getGroups()) {
+                        mPositionalData.add(new Pair<>(TYPE_GROUPED, group));
+                    }
+                } else {
+                    for (Event event : value.getValue()) {
+                        mPositionalData.add(new Pair<>(TYPE_UNGROUPED, event));
+                    }
+                }
+            }
         }
         for (Map.Entry<String, EventList> value: listsUngrouped.entrySet()) {
-            if (value.getValue().size() > 0)
-                mPositionalData.add(new Triplet<>(TYPE_UNGROUPED, value.getKey(), value.getValue()));
+            if (value.getValue().size() > 0) {
+                mPositionalData.add(new Pair<>(TYPE_HEADER, value.getKey()));
+                for (Event event : value.getValue()) {
+                    mPositionalData.add(new Pair<>(TYPE_UNGROUPED, event));
+                }
+            }
         }
         if (mPositionalData.size() == 0)
-            mPositionalData.add(new Triplet<>(TYPE_NONE, null, null));
+            mPositionalData.add(new Pair<>(TYPE_NONE, null));
         this.notifyDataSetChanged();
     }
 
@@ -92,66 +117,95 @@ class ModDetailEventAdapter extends RecyclerView.Adapter<CustomViewHolder> {
     public CustomViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view;
         switch (viewType) {
-            case TYPE_NONE:
+            case TYPE_GROUPED:
+            case TYPE_UNGROUPED:
+                view = LayoutInflater.from(parent.getContext())
+                        .inflate(R.layout.list_all_items, parent, false);
+                return new ItemViewHolder(view);
+            case TYPE_HEADER:
+                view = LayoutInflater.from(parent.getContext())
+                        .inflate(R.layout.list_all_caption, parent, false);
+                return new StringViewHolder(view);
+            default:
                 view = LayoutInflater.from(parent.getContext())
                         .inflate(R.layout.list_all_no_items, parent, false);
                 return new CustomViewHolder(view);
-            default:
-                view = LayoutInflater.from(parent.getContext())
-                        .inflate(R.layout.list_all_cardview_list, parent, false);
-                return new ListViewHolder(view);
         }
     }
 
     @Override
     public int getItemViewType(int position) {
         // Note that unlike in ListView adapters, types don't have to be contiguous
-        if (position < mPositionalData.size())
-            return mPositionalData.get(position).first;
-        else return -1;
+        return mPositionalData.get(position).first;
     }
 
     @Override
     public void onBindViewHolder(@NonNull final CustomViewHolder holder, int position) {
         if (mValue == null || position > mPositionalData.size())
             return;
-        Triplet<Integer, String, Object> data = mPositionalData.get(position);
-        if (data.first != TYPE_NONE) {
-            ListViewHolder h;
-            ModDetailEventAdapterInner adapter;
-            h = (ListViewHolder) holder;
-            Resources resources = h.mView.getResources();
-            adapter = new ModDetailEventAdapterInner();
-            String title;
-            switch (data.second) {
-                case VALUE_LECTURE:
+        Pair<Integer, Object> data = mPositionalData.get(position);
+        Resources resources = holder.mView.getResources();
+        Context context = holder.mView.getContext();
+        switch (data.first) {
+            case TYPE_HEADER:
+                StringViewHolder s = (StringViewHolder) holder;
+                String title = "";
+                if (VALUE_LECTURE.equals(data.second)) {
                     title = resources.getString(R.string.lecture);
-                    break;
-                case VALUE_TUTORIAL:
+
+                } else if (VALUE_TUTORIAL.equals(data.second)) {
                     title = resources.getString(R.string.tutorial);
-                    break;
-                case VALUE_EXAM:
+
+                } else if (VALUE_EXAM.equals(data.second)) {
                     title = resources.getString(R.string.exam);
-                    break;
-                case VALUE_DEADLINE:
+
+                } else if (VALUE_DEADLINE.equals(data.second)) {
                     title = resources.getString(R.string.deadline);
-                    break;
-                case VALUE_OTHER:
+
+                } else if (VALUE_OTHER.equals(data.second)) {
                     title = resources.getString(R.string.others);
-                    break;
-                default:
-                    title = data.second;
-            }
-            h.mString.setText(title);
-            switch (data.first) {
-                case TYPE_GROUPED:
-                    adapter.setData((GroupedEvents) data.third, h.mView.getContext());
-                    break;
-                case TYPE_UNGROUPED:
-                    adapter.setData((EventList) data.third, h.mView.getContext());
-                    break;
-            }
-            h.mList.setAdapter(adapter);
+                }
+                s.mString.setText(title);
+                return;
+            case TYPE_GROUPED:
+                ItemViewHolder ig = (ItemViewHolder) holder;
+                GroupedEvents.Group group = ((GroupedEvents.Group) data.second);
+                long firstDateTime = group.getFirstDate()+group.getStartTime();
+                long lastDateTime = group.getLastDate()+group.getStartTime()+group.getDuration();
+                String start, end, weekday, startTime, endTime;
+                StringBuilder excepts = null;
+                start = UtilsDate.getModifiedDate(firstDateTime);
+                end = UtilsDate.getModifiedDate(lastDateTime);
+                weekday = UtilsDate.getModifiedDate(context, firstDateTime, "E");
+                startTime = UtilsDate.getModifiedTime(context, firstDateTime);
+                endTime = UtilsDate.getModifiedTime(context, lastDateTime);
+                for (long skippedDate : group.getSkippedDates()) {
+                    if (excepts == null) {
+                        excepts = new StringBuilder(UtilsDate.getModifiedDate(skippedDate));
+                    } else {
+                        excepts.append(", ").append(UtilsDate.getModifiedDate(skippedDate));
+                    }
+                }
+                ig.mTitle.setText(context.getString(R.string.event_scale, weekday, startTime, endTime));
+                ig.mSubLeft.setText(context.getString(R.string.date_scale, start, end));
+                ig.mSubRight.setText(excepts != null ? context.getString(R.string.except_list, excepts.toString()) : "");
+                return;
+            case TYPE_UNGROUPED:
+                ItemViewHolder iu = (ItemViewHolder) holder;
+                Event event = (Event) data.second;
+                String date;
+                if (UtilsDate.dateEquals(event.getStartDate(), System.currentTimeMillis()))
+                    start = UtilsDate.getModifiedTime(context, event.getStartDate());
+                else
+                    start = UtilsDate.getModifiedDateTime(context, event.getStartDate());
+                if (UtilsDate.dateEquals(event.getStartDate(), event.getEndDate()))
+                    end = UtilsDate.getModifiedTime(context, event.getEndDate());
+                else
+                    end = UtilsDate.getModifiedDateTime(context, event.getEndDate());
+                date = context.getString(R.string.date_scale, start, end);
+                iu.mTitle.setText(event.getTitle());
+                iu.mSubLeft.setText(date);
+                iu.mSubRight.setText("");
         }
     }
 

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailEventAdapterInner.java

@@ -1,104 +0,0 @@
-package de.sebse.fuplanner.fragments.moddetails;
-
-import android.content.Context;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-
-import java.util.ArrayList;
-
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.RecyclerView;
-import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.types.Event;
-import de.sebse.fuplanner.services.KVV.types.EventList;
-import de.sebse.fuplanner.services.KVV.types.GroupedEvents;
-import de.sebse.fuplanner.tools.UtilsDate;
-import de.sebse.fuplanner.tools.ui.ItemViewHolder;
-
-class ModDetailEventAdapterInner extends RecyclerView.Adapter<ItemViewHolder> {
-    private final ArrayList<Entry> mPositionalData;
-
-    ModDetailEventAdapterInner() {
-        mPositionalData = new ArrayList<>();
-    }
-
-    public void setData(GroupedEvents events, final Context context) {
-        mPositionalData.clear();
-        for (GroupedEvents.Group group : events.getGroups()) {
-            long firstDateTime = group.getFirstDate()+group.getStartTime();
-            long lastDateTime = group.getLastDate()+group.getStartTime()+group.getDuration();
-            String start, end, weekday, startTime, endTime;
-            StringBuilder excepts = null;
-            start = UtilsDate.getModifiedDate(firstDateTime);
-            end = UtilsDate.getModifiedDate(lastDateTime);
-            weekday = UtilsDate.getModifiedDate(context, firstDateTime, "E");
-            startTime = UtilsDate.getModifiedTime(context, firstDateTime);
-            endTime = UtilsDate.getModifiedTime(context, lastDateTime);
-            for (long skippedDate : group.getSkippedDates()) {
-                if (excepts == null) {
-                    excepts = new StringBuilder(UtilsDate.getModifiedDate(skippedDate));
-                } else {
-                    excepts.append(", ").append(UtilsDate.getModifiedDate(skippedDate));
-                }
-            }
-            mPositionalData.add(new Entry(
-                    context.getString(R.string.event_scale, weekday, startTime, endTime),
-                    context.getString(R.string.date_scale, start, end),
-                    excepts != null ? context.getString(R.string.except_list, excepts.toString()) : ""));
-        }
-        this.notifyDataSetChanged();
-    }
-
-    public void setData(EventList events, final Context context) {
-        mPositionalData.clear();
-        for (Event event : events) {
-            String date;
-            String start, end;
-            if (UtilsDate.dateEquals(event.getStartDate(), System.currentTimeMillis()))
-                start = UtilsDate.getModifiedTime(context, event.getStartDate());
-            else
-                start = UtilsDate.getModifiedDateTime(context, event.getStartDate());
-            if (UtilsDate.dateEquals(event.getStartDate(), event.getEndDate()))
-                end = UtilsDate.getModifiedTime(context, event.getEndDate());
-            else
-                end = UtilsDate.getModifiedDateTime(context, event.getEndDate());
-            date = context.getString(R.string.date_scale, start, end);
-            mPositionalData.add(new Entry(event.getTitle(), date, ""));
-        }
-        this.notifyDataSetChanged();
-    }
-
-    @NonNull
-    @Override
-    public ItemViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
-        View view;
-        view = LayoutInflater.from(parent.getContext())
-                .inflate(R.layout.list_all_items, parent, false);
-        return new ItemViewHolder(view);
-    }
-
-    @Override
-    public void onBindViewHolder(@NonNull final ItemViewHolder holder, int position) {
-        holder.mTitle.setText(mPositionalData.get(position).title);
-        holder.mSubLeft.setText(mPositionalData.get(position).subtitleLeft);
-        holder.mSubRight.setText(mPositionalData.get(position).subtitleRight);
-    }
-
-    @Override
-    public int getItemCount() {
-        return mPositionalData.size();
-    }
-
-    private class Entry {
-        private String title;
-        private String subtitleLeft;
-        private String subtitleRight;
-
-        private Entry(String title, String subtitleLeft, String subtitleRight) {
-            this.title = title;
-            this.subtitleLeft = subtitleLeft;
-            this.subtitleRight = subtitleRight;
-        }
-    }
-}

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailEventFragment.java

@@ -83,9 +83,10 @@ public class ModDetailEventFragment extends Fragment {
     private void refresh(boolean forceRefresh) {
         if (mListener == null)
             return;
-        mListener.getKVV().modules().events().recv(mItemPos, success -> {
-            adapter.setModule(success);
-            swipeLayout.setRefreshing(false);
+        mListener.getKVV().modules().details().recv(mItemPos, pair -> {
+            adapter.setModule(pair.first);
+            if (pair.second)
+                swipeLayout.setRefreshing(false);
         }, error -> {
             swipeLayout.setRefreshing(false);
             log.e(error);

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailFragment.java

@@ -10,7 +10,7 @@ import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
 import androidx.viewpager.widget.ViewPager;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.logging.Logger;
 
@@ -48,7 +48,7 @@ public class ModDetailFragment extends Fragment implements ModDetailListener {
         ModDetailFragment fragment = new ModDetailFragment();
         Bundle args = new Bundle();
         if (!itemPosition.contains("."))
-            args.putString(ARG_POSITION, itemPosition+"."+0);
+            args.putString(ARG_POSITION, itemPosition+".0");
         else
             args.putString(ARG_POSITION, itemPosition);
 

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailGradebookAdapter.java

@@ -12,8 +12,8 @@ import java.util.ArrayList;
 import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.RecyclerView;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.types.Grade;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Grade;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.ui.StringViewHolder;
 
 class ModDetailGradebookAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
@@ -36,20 +36,16 @@ class ModDetailGradebookAdapter extends RecyclerView.Adapter<RecyclerView.ViewHo
         this.setModule();
     }
 
-    public void setModule() {
+    private void setModule() {
         mPositionalData.clear();
         mPositionalData.add(new Pair<>(TYPE_TOTAL, SECTION_GRADE));
-        addPositionalListData(getGradesCount(), SECTION_GRADE);
+        for (int i = 0; i < getGradesCount(); i++) {
+            mPositionalData.add(new Pair<>(TYPE_GRADE, SECTION_GRADE +1024*i));
+        }
 
         this.notifyDataSetChanged();
     }
 
-    private void addPositionalListData(int count, int category) {
-        for (int i = 0; i < count; i++) {
-            mPositionalData.add(new Pair<>(TYPE_GRADE, category+1024*i));
-        }
-    }
-
     @NonNull
     @Override
     public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
@@ -131,6 +127,7 @@ class ModDetailGradebookAdapter extends RecyclerView.Adapter<RecyclerView.ViewHo
             mGradeMax = view.findViewById(R.id.grade_max);
         }
 
+        @NonNull
         @Override
         public String toString() {
             return super.toString() + " '" + mTitle.getText() + " '" + mGrade.getText() + " '" + mGradeMax.getText() + "'";

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailGradebookFragment.java

@@ -83,9 +83,10 @@ public class ModDetailGradebookFragment extends Fragment {
     private void refresh(boolean forceRefresh) {
         if (mListener == null)
             return;
-        mListener.getKVV().modules().gradebook().recv(mItemPos, success -> {
-            adapter.setModule(success);
-            swipeLayout.setRefreshing(false);
+        mListener.getKVV().modules().details().recv(mItemPos, pair -> {
+            adapter.setModule(pair.first);
+            if (pair.second)
+                swipeLayout.setRefreshing(false);
         }, error -> {
             swipeLayout.setRefreshing(false);
             log.e(error);

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailOverviewAdapter.java

@@ -15,16 +15,17 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.recyclerview.widget.RecyclerView;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.types.Announcement;
-import de.sebse.fuplanner.services.KVV.types.Assignment;
-import de.sebse.fuplanner.services.KVV.types.Event;
-import de.sebse.fuplanner.services.KVV.types.Lecturer;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Announcement;
+import de.sebse.fuplanner.services.kvv.types.Assignment;
+import de.sebse.fuplanner.services.kvv.types.Event;
+import de.sebse.fuplanner.services.kvv.types.Lecturer;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.UtilsDate;
 import de.sebse.fuplanner.tools.logging.Logger;
 import de.sebse.fuplanner.tools.ui.CustomViewHolder;
 import de.sebse.fuplanner.tools.ui.ItemViewHolder;
 import de.sebse.fuplanner.tools.ui.MailViewHolder;
+import de.sebse.fuplanner.tools.ui.ShortcutViewHolder;
 import de.sebse.fuplanner.tools.ui.StringViewHolder;
 
 class ModDetailOverviewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
@@ -35,6 +36,7 @@ class ModDetailOverviewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
     private static final int TYPE_ITEM = 2;
     private static final int TYPE_SHOW_MORE = 3;
     private static final int TYPE_MAIL = 4;
+    private static final int TYPE_SHORTCUTS = 5;
 
     @Nullable private final ModDetailListener mListener;
 
@@ -53,10 +55,11 @@ class ModDetailOverviewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
         this.setModule();
     }
 
-    public void setModule() {
+    private void setModule() {
         mPositionalData.clear();
         mPositionalData.add(new Pair<>(TYPE_HEADER, ModulePart.DESCRIPTION));
         mPositionalData.add(new Pair<>(TYPE_DESCRIPTION, null));
+        mPositionalData.add(new Pair<>(TYPE_SHORTCUTS, null));
         mPositionalData.add(new Pair<>(TYPE_HEADER, ModulePart.LECTURERS));
         for (int i = 0; i < mValue.lecturer.size(); i++) {
             mPositionalData.add(new Pair<>(TYPE_MAIL, ModulePart.LECTURERS+1024*i));
@@ -103,6 +106,10 @@ class ModDetailOverviewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                 view = LayoutInflater.from(parent.getContext())
                         .inflate(R.layout.list_all_mails, parent, false);
                 return new MailViewHolder(view);
+            case TYPE_SHORTCUTS:
+                view = LayoutInflater.from(parent.getContext())
+                        .inflate(R.layout.list_moddetails_shortcuts, parent, false);
+                return new ShortcutViewHolder(view);
             default:
                 //noinspection ConstantConditions
                 return null;
@@ -214,10 +221,20 @@ class ModDetailOverviewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                             emailIntent.setData(Uri.parse("mailto:"+lecturer.getMail()));
                             emailIntent.putExtra(Intent.EXTRA_SUBJECT, mValue.title);
                             emailIntent.putExtra(Intent.EXTRA_TEXT, defaultText);
-                            m.mView.getContext().startActivity(Intent.createChooser(emailIntent, mValue.title));
+                            m.mView.getContext().startActivity(emailIntent);
                         });
                         break;
                 }
+                break;
+            case TYPE_SHORTCUTS:
+                ShortcutViewHolder s = (ShortcutViewHolder) holder;
+                s.mLeft.setOnClickListener(view -> {
+                    if (mListener != null) mListener.gotoFragmentPart(ModulePart.RESOURCES, -1);
+                });
+                s.mRight.setOnClickListener(view -> {
+                    if (mListener != null) mListener.gotoFragmentPart(ModulePart.GRADEBOOK, -1);
+                });
+                break;
             case TYPE_SHOW_MORE:
                 CustomViewHolder c = (CustomViewHolder) holder;
                 c.mView.setOnClickListener(view -> {

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailResourceAdapter.java

@@ -3,8 +3,8 @@ package de.sebse.fuplanner.fragments.moddetails;
 import java.util.ArrayList;
 import java.util.List;
 
-import de.sebse.fuplanner.services.KVV.types.Modules;
-import de.sebse.fuplanner.services.KVV.types.Resource;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Resource;
 import de.sebse.fuplanner.tools.ui.treeview.TreeNode;
 import de.sebse.fuplanner.tools.ui.treeview.TreeViewAdapter;
 import de.sebse.fuplanner.tools.ui.treeview.TreeViewBinder;
@@ -21,7 +21,7 @@ class ModDetailResourceAdapter extends TreeViewAdapter {
         this.setModule();
     }
 
-    public void setModule() {
+    private void setModule() {
         if (mValue == null || mValue.resources == null) {
             return;
         }

app/src/main/java/de/sebse/fuplanner/fragments/moddetails/ModDetailResourceFragment.java

@@ -18,9 +18,9 @@ import androidx.recyclerview.widget.RecyclerView;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import de.sebse.fuplanner.MainActivity;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.ui.Download;
-import de.sebse.fuplanner.services.KVV.types.Modules;
-import de.sebse.fuplanner.services.KVV.types.Resource;
+import de.sebse.fuplanner.services.kvv.ui.Download;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Resource;
 import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.logging.Logger;
 import de.sebse.fuplanner.tools.ui.treeview.DirectoryNodeBinder;
@@ -140,16 +140,17 @@ public class ModDetailResourceFragment extends Fragment {
     private void refresh(boolean forceRefresh) {
         if (mListener == null)
             return;
-        mListener.getKVV().modules().assignments().recv(mItemPos, success -> {
-            adapter.setModule(success);
-            swipeLayout.setRefreshing(false);
+        mListener.getKVV().modules().details().recv(mItemPos, pair -> {
+            adapter.setModule(pair.first);
+            if (pair.second)
+                swipeLayout.setRefreshing(false);
         }, error -> {
             swipeLayout.setRefreshing(false);
             log.e(error);
         }, forceRefresh);
     }
 
-    Download getDownload() {
+    private Download getDownload() {
         if (download == null)
             download = new Download(this::getContext, () -> (MainActivity) getActivity());
         return download;

app/src/main/java/de/sebse/fuplanner/services/GoogleAuth/ConnectedListener.java

@@ -1,9 +0,0 @@
-package de.sebse.fuplanner.services.GoogleAuth;
-
-/**
- * Created by sebastian on 07.11.17.
- */
-
-public interface ConnectedListener {
-    void connected();
-}

app/src/main/java/de/sebse/fuplanner/services/GoogleAuth/Credentials.java

@@ -1,23 +0,0 @@
-package de.sebse.fuplanner.services.GoogleAuth;
-
-/**
- * Created by Sebastian on 06.11.2017.
- */
-
-public class Credentials {
-    private final String username;
-    private final String password;
-
-    public Credentials(String username, String password) {
-        this.username = username;
-        this.password = password;
-    }
-
-    public String getUsername() {
-        return username;
-    }
-
-    public String getPassword() {
-        return password;
-    }
-}

app/src/main/java/de/sebse/fuplanner/services/GoogleAuth/CredentialsListener.java

@@ -1,9 +0,0 @@
-package de.sebse.fuplanner.services.GoogleAuth;
-
-/**
- * Created by Sebastian on 06.11.2017.
- */
-
-public interface CredentialsListener {
-    void onCredentials(Credentials credentials);
-}

app/src/main/java/de/sebse/fuplanner/services/GoogleAuth/GoogleAuth.java

@@ -1,224 +0,0 @@
-package de.sebse.fuplanner.services.GoogleAuth;
-
-import android.content.Intent;
-import android.content.IntentSender;
-import android.util.Log;
-import android.widget.Toast;
-
-import com.google.android.gms.auth.api.credentials.Credential;
-import com.google.android.gms.auth.api.credentials.CredentialRequest;
-import com.google.android.gms.auth.api.credentials.CredentialsClient;
-import com.google.android.gms.auth.api.credentials.CredentialsOptions;
-import com.google.android.gms.common.ConnectionResult;
-import com.google.android.gms.common.GoogleApiAvailability;
-import com.google.android.gms.common.api.ApiException;
-import com.google.android.gms.common.api.CommonStatusCodes;
-import com.google.android.gms.common.api.ResolvableApiException;
-
-import androidx.annotation.Nullable;
-import androidx.fragment.app.FragmentActivity;
-
-import static android.app.Activity.RESULT_OK;
-
-/**
- * Created by Sebastian on 06.11.2017.
- */
-
-public class GoogleAuth {
-    // https://developers.google.com/identity/smartlock-passwords/android/retrieve-credentials
-
-    private static final String TAG = "GoogleAuth";
-    private final FragmentActivity activity;
-    private static final String FU_PLANNER_PROVIDER = "FUPlanner";
-    private CredentialsClient mCredentialsClient;
-    private boolean mIsResolving;
-    @Nullable
-    private CredentialsListener mCredentialsListener;
-    private boolean isConnected = false;
-
-    public GoogleAuth(FragmentActivity activity) {
-        this.activity = activity;
-    }
-
-    private void connect() {
-        if (this.isUnavailable()) {
-            Log.d(TAG, "STATUS: Google auth not available!");
-            return;
-        }
-        this.mCredentialsClient = getClient();
-        this.isConnected = true;
-    }
-
-
-
-
-    public void getLoginState(final CredentialsListener credentialsListener) {
-        if (this.isUnavailable()) {
-            Log.d(TAG, "STATUS: Google auth not available!");
-            credentialsListener.onCredentials(null);
-            return;
-        }
-        if (!this.isConnected)
-            connect();
-        CredentialRequest request = new CredentialRequest.Builder()
-                .setPasswordLoginSupported(true)
-                .setAccountTypes(FU_PLANNER_PROVIDER)
-                .build();
-
-
-        mCredentialsClient.request(request).addOnCompleteListener(task -> {
-            if (task.isSuccessful()) {
-                // Successfully read the credential without any user interaction, this
-                // means there was only a single credential and the user has auto
-                // sign-in enabled.
-                Credential credential = task.getResult().getCredential();
-                credentialsListener.onCredentials(new Credentials(credential.getId(), credential.getPassword()));
-                return;
-            }
-
-            Exception e = task.getException();
-            if (e instanceof ResolvableApiException) {
-                // This is most likely the case where the user has multiple saved
-                // credentials and needs to pick one. This requires showing UI to
-                // resolve the read request.
-                GoogleAuth.this.mCredentialsListener = credentialsListener;
-                ResolvableApiException rae = (ResolvableApiException) e;
-                resolveResult(rae, RequestCode.RC_READ);
-                return;
-            }
-
-            if (e instanceof ApiException) {
-                ApiException ae = (ApiException) e;
-                if (ae.getStatusCode() == CommonStatusCodes.SIGN_IN_REQUIRED) {
-                    // This means only a hint is available, but we are handling that
-                    // elsewhere so no need to act here.
-                } else {
-                    credentialsListener.onCredentials(null);
-                    Log.w(TAG, "Unexpected status code: " + ae.getStatusCode());
-                }
-            }
-        });
-    }
-
-    public void setLoginState(String username, String password) {
-        if (this.isUnavailable()) {
-            Log.d(TAG, "STATUS: Google auth not available!");
-            Toast.makeText(activity, "Google auth not available!", Toast.LENGTH_SHORT).show();
-            return;
-        }
-        if (!this.isConnected)
-            connect();
-        Credential credential = new Credential.Builder(username)
-                .setPassword(password)
-                .build();
-        mCredentialsClient.save(credential).addOnCompleteListener(task -> {
-            if (task.isSuccessful()) {
-                showToast("Credential saved.");
-                return;
-            }
-
-            Exception e = task.getException();
-            if (e instanceof ResolvableApiException) {
-                // The first time a credential is saved, the user is shown UI
-                // to confirm the action. This requires resolution.
-                ResolvableApiException rae = (ResolvableApiException) e;
-                resolveResult(rae, RequestCode.RC_SAVE);
-            } else {
-                // Save failure cannot be resolved.
-                Log.w(TAG, "Save failed.", e);
-                showToast("Credential Save Failed");
-            }
-        });
-    }
-
-    public void deleteLoginState(String username, String password) {
-        if (this.isUnavailable()) {
-            Log.d(TAG, "STATUS: Google auth not available!");
-            return;
-        }
-        if (!this.isConnected)
-            connect();
-        Credential credential = new Credential.Builder(username)
-                .setPassword(password)
-                .build();
-        mCredentialsClient.delete(credential).addOnCompleteListener(task -> {
-            if (task.isSuccessful()) {
-                // Credential was deleted successfully
-            }
-        });
-    }
-
-
-    private boolean isUnavailable() {
-        return GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(this.activity) != ConnectionResult.SUCCESS;
-    }
-
-    private CredentialsClient getClient() {
-        CredentialsOptions options = new CredentialsOptions.Builder()
-                .forceEnableSaveDialog()
-                .build();
-        return com.google.android.gms.auth.api.credentials.Credentials.getClient(this.activity, options);
-    }
-
-    public void onActivityResult(int requestCode, int resultCode, Intent data) {
-        Log.d(TAG, "onActivityResult:" + requestCode + ":" + resultCode + ":" + data);
-
-        switch (requestCode) {
-            case RequestCode.RC_HINT:
-                // Drop into handling for RC_READ
-            case RequestCode.RC_READ:
-                if (resultCode == RESULT_OK) {
-                    boolean isHint = (requestCode == RequestCode.RC_HINT);
-                    Credential credential = data.getParcelableExtra(Credential.EXTRA_KEY);
-                    if (mCredentialsListener != null)
-                        this.mCredentialsListener.onCredentials(new Credentials(credential.getId(), credential.getPassword()));
-                    else
-                        Log.d(TAG, "No Credentials Listener");
-                } else {
-                    if (mCredentialsListener != null)
-                        this.mCredentialsListener.onCredentials(null);
-                    else
-                        Log.d(TAG, "No Credentials Listener");
-                    Log.e(TAG, "Credential Read: NOT OK");
-                    showToast("Credential Read Failed");
-                }
-
-                mIsResolving = false;
-                break;
-            case RequestCode.RC_SAVE:
-                if (resultCode == RESULT_OK) {
-                    Log.d(TAG, "Credential Save: OK");
-                    showToast("Credential Save Success");
-                } else {
-                    Log.e(TAG, "Credential Save: NOT OK");
-                    showToast("Credential Save Failed");
-                }
-
-                mIsResolving = false;
-                break;
-        }
-    }
-
-
-    private void resolveResult(ResolvableApiException rae, int requestCode) {
-        // We don't want to fire multiple resolutions at once since that can result
-        // in stacked dialogs after rotation or another similar event.
-        if (mIsResolving) {
-            Log.w(TAG, "resolveResult: already resolving.");
-            return;
-        }
-
-        Log.d(TAG, "Resolving: " + rae);
-        try {
-            rae.startResolutionForResult(this.activity, requestCode);
-            mIsResolving = true;
-        } catch (IntentSender.SendIntentException e) {
-            Log.e(TAG, "STATUS: Failed to send resolution.", e);
-        }
-    }
-
-    /** Display a short Toast message **/
-    private void showToast(String msg) {
-        Toast.makeText(this.activity, msg, Toast.LENGTH_SHORT).show();
-    }
-}

app/src/main/java/de/sebse/fuplanner/services/GoogleAuth/RequestCode.java

@@ -1,11 +0,0 @@
-package de.sebse.fuplanner.services.GoogleAuth;
-
-/**
- * Created by sebastian on 07.11.17.
- */
-
-class RequestCode {
-    public static final int RC_SAVE = 1;
-    public static final int RC_HINT = 2;
-    public static final int RC_READ = 3;
-}

app/src/main/java/de/sebse/fuplanner/services/KVV/KVVListener.java

@@ -1,20 +0,0 @@
-package de.sebse.fuplanner.services.KVV;
-
-import com.android.volley.NetworkResponse;
-
-import de.sebse.fuplanner.services.GoogleAuth.Credentials;
-import de.sebse.fuplanner.services.KVV.types.LoginToken;
-import de.sebse.fuplanner.tools.network.NetworkCallback;
-import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
-
-public interface KVVListener {
-    void getCredentials(NetworkCallback<Credentials> callback, NetworkErrorCallback error);
-
-    void onLogin(LoginToken token, boolean enteringOnlineMode);
-
-    void onLogout();
-
-    void onModuleListChange();
-
-    void onKVVNetworkResponse(NetworkResponse error);
-}

app/src/main/java/de/sebse/fuplanner/services/KVV/types/LoginToken.java

@@ -1,117 +0,0 @@
-package de.sebse.fuplanner.services.KVV.types;
-
-import android.content.Context;
-
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
-import java.io.Serializable;
-import java.util.HashMap;
-
-import androidx.annotation.Nullable;
-
-/**
- * Created by sebastian on 29.10.17.
- */
-
-public class LoginToken implements Serializable {
-    private static final String FILE_NAME = "LoginTokenSaving";
-
-    private final String username;
-    private final String shibsessionKey;
-    private final String shibsessionName;
-    private final String JSESSIONID;
-    @Nullable private String fullName;
-    @Nullable private String email;
-
-    public LoginToken(String username, String shibsessionKey, String shibsessionName, String JSESSIONID) {
-        this.username = username;
-        this.shibsessionKey = shibsessionKey;
-        this.shibsessionName = shibsessionName;
-        this.JSESSIONID = JSESSIONID;
-    }
-
-    @Nullable
-    public static LoginToken load(Context context) throws IOException, ClassNotFoundException {
-        FileInputStream fis;
-        try {
-            fis = context.openFileInput(FILE_NAME);
-        } catch (FileNotFoundException e) {
-            return null;
-        }
-        ObjectInputStream is = new ObjectInputStream(fis);
-        Object readObject = is.readObject();
-        if (!(readObject instanceof LoginToken))
-            return null;
-        LoginToken loginToken = (LoginToken) readObject;
-        is.close();
-        fis.close();
-        return loginToken;
-    }
-
-    public void save(Context context) throws IOException {
-        FileOutputStream fos = context.openFileOutput(FILE_NAME, Context.MODE_PRIVATE);
-        ObjectOutputStream os = new ObjectOutputStream(fos);
-        os.writeObject(this);
-        os.close();
-        fos.close();
-    }
-
-    public void delete(Context context) {
-        context.deleteFile(FILE_NAME);
-    }
-
-    public void setAdditionals(String fullName, String email) {
-        this.fullName = fullName;
-        this.email = email;
-    }
-
-    public String getUsername() {
-        return username;
-    }
-
-    private String getShibsessionKey() {
-        return shibsessionKey;
-    }
-
-    private String getShibsessionName() {
-        return shibsessionName;
-    }
-
-    private String getJSESSIONID() {
-        return JSESSIONID;
-    }
-
-    public String getFullName() {
-        return fullName;
-    }
-
-    public String getEmail() {
-        return email;
-    }
-
-    public HashMap<String, String> getCookies() {
-        HashMap<String, String> cookies = new HashMap<>();
-        cookies.put("JSESSIONID", getJSESSIONID());
-        cookies.put(getShibsessionKey(), getShibsessionName());
-        cookies.put("pasystem_timezone_ok", "true");
-        return cookies;
-    }
-
-    public boolean isSameUser(String username) {
-        return this.getUsername().equals(username);
-    }
-
-    @Override
-    public String toString() {
-        StringBuilder result = new StringBuilder();
-        HashMap<String, String> cookies = this.getCookies();
-        for (String header: cookies.keySet()) {
-            result.append(header).append("=").append(cookies.get(header)).append(";");
-        }
-        return result.substring(0, result.length()-1);
-    }
-}

app/src/main/java/de/sebse/fuplanner/services/KVV/types/Modules.java

@@ -1,170 +0,0 @@
-package de.sebse.fuplanner.services.KVV.types;
-
-import android.content.Context;
-
-import org.jetbrains.annotations.NotNull;
-
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
-import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.LinkedHashSet;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
-/**
- * Created by sebastian on 29.10.17.
- */
-
-public class Modules implements Iterable<Modules.Module>, Serializable {
-    private SortedListModule list;
-    private final String mUsername;
-    //private transient Logger log = new Logger(this);
-    private static final String FILE_NAME = "ModuleListSaving";
-
-    public Modules(String username) {
-        this.mUsername = username;
-        this.list = new SortedListModule();
-    }
-
-    public void addModule(@Nullable Semester semester, HashSet<String> lvNumber, String title, LinkedHashSet<Lecturer> lecturer, String type, String description, String ID) {
-        Module m = new Module(semester, lvNumber, title, lecturer, type, description, ID);
-        this.list.add(m);
-    }
-
-    @NonNull
-    @Override
-    public String toString() {
-        return this.list.toString();
-    }
-
-    @NonNull
-    @Override
-    public Iterator<Module> iterator() {
-        return this.list.iterator();
-    }
-
-    public Iterator<Module> latestSemesterIterator() {
-        return this.list.filteredIterator(this.list.getLatestSemester());
-    }
-
-    public int size() {
-        return this.list.size();
-    }
-
-    public Module get(String id) {
-        return this.list.getById(id);
-    }
-
-    public Module getByIndex(int index) {
-        return this.list.get(index);
-    }
-
-    public static Modules load(Context context) throws IOException, ClassNotFoundException {
-        FileInputStream fis = context.openFileInput(FILE_NAME);
-        ObjectInputStream is = new ObjectInputStream(fis);
-        Object readObject = is.readObject();
-        if (!(readObject instanceof Modules))
-            return null;
-        Modules modules = (Modules) readObject;
-        is.close();
-        fis.close();
-        return modules;
-    }
-
-    public void save(Context context) throws IOException {
-        FileOutputStream fos = context.openFileOutput(FILE_NAME, Context.MODE_PRIVATE);
-        ObjectOutputStream os = new ObjectOutputStream(fos);
-        os.writeObject(this);
-        os.close();
-        fos.close();
-    }
-
-    public void delete(Context context) {
-        context.deleteFile(FILE_NAME);
-    }
-
-    public String getUsername() {
-        return mUsername;
-    }
-
-    public void updateList(Modules modules) {
-        SortedListModule old = this.list;
-        this.list = modules.list;
-        for (Module oldModule : old) {
-            Module newModule = this.list.getById(oldModule.getID());
-            if (newModule != null) {
-                newModule.announcements = oldModule.announcements;
-                newModule.assignments = oldModule.assignments;
-                newModule.events = oldModule.events;
-                newModule.gradebook = oldModule.gradebook;
-                newModule.resources = oldModule.resources;
-            }
-        }
-    }
-
-    public class Module implements Serializable {
-        @Nullable public final Semester semester;
-        @NotNull final HashSet<String> lvNumber;
-        @NotNull public final String title;
-        @NotNull
-        public final ArrayList<Lecturer> lecturer;
-        @Nullable public final String type;
-        @Nullable public final String description;
-        @NotNull private final String ID;
-        @Nullable public ArrayList<Announcement> announcements;
-        @Nullable public AssignmentList assignments;
-        @Nullable public EventList events;
-        @Nullable public ArrayList<Grade> gradebook;
-        @Nullable public ArrayList<Resource> resources;
-
-        public float getGradebookPercent(){
-            float maxPoint = 0;
-            float userPoint = 0;
-            if (gradebook != null) {
-                for (Grade g : gradebook){
-                    maxPoint += g.getMaxPoints();
-                    userPoint += g.getPoints();
-                }
-            }
-            if (maxPoint == 0)
-                return 0;
-            return userPoint/maxPoint;
-        }
-
-        private Module(@Nullable Semester semester, @NotNull HashSet<String> lvNumber, @NotNull String title, @NotNull LinkedHashSet<Lecturer> lecturer, @Nullable String type, @Nullable String description, @NotNull String ID) {
-
-            title = title.replaceAll("(.*?) (S[0-9]{2}|W[0-9/]{5})", "$1");
-
-            this.semester = semester;
-            this.lvNumber = lvNumber;
-            this.title = title;
-            this.lecturer = new ArrayList<>(lecturer);
-            this.type = type;
-            this.description = description;
-            this.ID = ID;
-        }
-
-        @NonNull
-        public String getID() {
-            return ID;
-        }
-
-        @NonNull
-        @Override
-        public String toString() {
-            return "Semester: "+semester+
-                    "\nlvNumber: "+lvNumber.toString()+
-                    "\ntitle: "+title+
-                    "\nlecturer: "+lecturer.toString()+
-                    "\ntype: "+type+
-                    "\nID: "+ID;
-        }
-    }
-}

app/src/main/java/de/sebse/fuplanner/services/canteen/CanteenBrowser.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.Canteen;
+package de.sebse.fuplanner.services.canteen;
 
 import android.content.Context;
 
@@ -8,12 +8,11 @@ import org.json.JSONObject;
 
 import java.io.IOException;
 
-import de.sebse.fuplanner.MainActivity;
-import de.sebse.fuplanner.services.Canteen.types.Canteen;
-import de.sebse.fuplanner.services.Canteen.types.Canteens;
-import de.sebse.fuplanner.services.Canteen.types.Day;
+import de.sebse.fuplanner.services.canteen.types.Canteen;
+import de.sebse.fuplanner.services.canteen.types.CanteenListener;
+import de.sebse.fuplanner.services.canteen.types.Canteens;
+import de.sebse.fuplanner.services.canteen.types.Day;
 import de.sebse.fuplanner.tools.AsyncQueue;
-import de.sebse.fuplanner.tools.MainActivityListener;
 import de.sebse.fuplanner.tools.network.HTTPService;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
@@ -23,15 +22,15 @@ public class CanteenBrowser extends HTTPService {
     private Canteens canteens;
     private final AsyncQueue queue = new AsyncQueue();
     private final Context context;
-    private MainActivityListener mListener;
+    private CanteenListener mListener;
 
     public CanteenBrowser(Context context) {
         super(context);
         this.context = context;
-        if (context instanceof MainActivityListener)
-            mListener = (MainActivity) context;
+        if (context instanceof CanteenListener)
+            mListener = (CanteenListener) context;
         else
-            throw new RuntimeException(context.toString() + " must implement MainActivityListener");
+            throw new RuntimeException(context.toString() + " must implement CanteenListener");
         try {
             this.canteens = Canteens.load(context);
         } catch (IOException e) {
@@ -206,7 +205,6 @@ public class CanteenBrowser extends HTTPService {
                 }
             } catch (JSONException e) {
                 e.printStackTrace();
-                log.d(body);
                 errorCallback.onError(new NetworkError(201302, 403, "Cannot parse meal list!"));
                 return;
             }
@@ -225,14 +223,14 @@ public class CanteenBrowser extends HTTPService {
     private<T> NetworkCallback<T> saveOnCallback(NetworkCallback<T> callback, boolean forceRefresh){
         return (success -> {
             if (forceRefresh)
-                mListener.onRefreshCompleted(false);
+                mListener.onCanteenRefreshCompleted(false);
             callback.onResponse(success);
         });
     }
 
     private NetworkErrorCallback errorOnCallback(NetworkErrorCallback errorCallback){
         return (error -> {
-            mListener.onRefreshCompleted(true);
+            mListener.onCanteenRefreshCompleted(true);
             errorCallback.onError(error);
         });
     }

app/src/main/java/de/sebse/fuplanner/services/canteen/types/Canteen.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.Canteen.types;
+package de.sebse.fuplanner.services.canteen.types;
 
 import androidx.annotation.NonNull;
 
@@ -121,6 +121,7 @@ public class Canteen implements Serializable, Iterable<Day> {
         return lng;
     }
 
+    @NonNull
     @Override
     public String toString() {
         return id+": "+name+"\n"+list.toString()+"\n";

app/src/main/java/de/sebse/fuplanner/services/canteen/types/CanteenListener.java

@@ -0,0 +1,5 @@
+package de.sebse.fuplanner.services.canteen.types;
+
+public interface CanteenListener {
+    void onCanteenRefreshCompleted(boolean b);
+}

app/src/main/java/de/sebse/fuplanner/services/canteen/types/Canteens.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.Canteen.types;
+package de.sebse.fuplanner.services.canteen.types;
 
 import android.content.Context;
 import androidx.annotation.NonNull;
@@ -94,6 +94,7 @@ public class Canteens implements Serializable, Iterable<Canteen> {
         context.deleteFile(FILE_NAME);
     }
 
+    @NonNull
     @Override
     public String toString() {
         return this.list.toString();

app/src/main/java/de/sebse/fuplanner/services/canteen/types/Day.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.Canteen.types;
+package de.sebse.fuplanner.services.canteen.types;
 
 import androidx.annotation.NonNull;
 
@@ -58,6 +58,7 @@ public class Day implements Serializable, Iterable<Meal> {
         return canteenId;
     }
 
+    @NonNull
     @Override
     public String toString() {
         return Canteen.calendarToKey(getCalendar())+"\n"+this.list+"\n";

app/src/main/java/de/sebse/fuplanner/services/canteen/types/Meal.java

@@ -1,10 +1,12 @@
-package de.sebse.fuplanner.services.Canteen.types;
+package de.sebse.fuplanner.services.canteen.types;
 
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
+import androidx.annotation.NonNull;
+
 public class Meal implements Serializable {
     private static final int LIGHT_NONE = 0;
     private static final int LIGHT_GREEN = 1;
@@ -112,6 +114,7 @@ public class Meal implements Serializable {
         return certificates;
     }
 
+    @NonNull
     @Override
     public String toString() {
         return name + " (" + category + ")";

app/src/main/java/de/sebse/fuplanner/services/canteen/types/SortedListCanteen.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.Canteen.types;
+package de.sebse.fuplanner.services.canteen.types;
 
 import de.sebse.fuplanner.tools.SortedList;
 

app/src/main/java/de/sebse/fuplanner/services/canteen/types/SortedListDay.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.Canteen.types;
+package de.sebse.fuplanner.services.canteen.types;
 
 import java.util.Calendar;
 

app/src/main/java/de/sebse/fuplanner/services/canteen/types/SortedListMeal.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.Canteen.types;
+package de.sebse.fuplanner.services.canteen.types;
 
 import de.sebse.fuplanner.tools.SortedList;
 

app/src/main/java/de/sebse/fuplanner/services/fulogin/AccountGeneral.java

@@ -0,0 +1,7 @@
+package de.sebse.fuplanner.services.fulogin;
+
+public class AccountGeneral {
+    public static final String ACCOUNT_TYPE = "de.sebse.fuplanner.fuauth";
+    public static final String AUTHTOKEN_TYPE_KVV = "KVV";
+    public static final String AUTHTOKEN_TYPE_BLACKBOARD = "Blackboard";
+}

app/src/main/java/de/sebse/fuplanner/services/fulogin/FUAuthenticator.java

@@ -0,0 +1,104 @@
+package de.sebse.fuplanner.services.fulogin;
+
+import android.accounts.AbstractAccountAuthenticator;
+import android.accounts.Account;
+import android.accounts.AccountAuthenticatorResponse;
+import android.accounts.AccountManager;
+import android.accounts.NetworkErrorException;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.text.TextUtils;
+
+import java.util.concurrent.ExecutionException;
+
+public class FUAuthenticator extends AbstractAccountAuthenticator {
+
+    private final Context mContext;
+
+    public FUAuthenticator(Context context) {
+        super(context);
+        this.mContext = context;
+    }
+
+    @Override
+    public Bundle editProperties(AccountAuthenticatorResponse accountAuthenticatorResponse, String s) {
+        return null;
+    }
+
+    @Override
+    public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType, String[] requiredFeatures, Bundle options) throws NetworkErrorException {
+        final Intent intent = new Intent(mContext, FUAuthenticatorActivity.class);
+        intent.putExtra(FUAuthenticatorActivity.ARG_ACCOUNT_TYPE, accountType);
+        intent.putExtra(FUAuthenticatorActivity.ARG_AUTH_TYPE, authTokenType);
+        intent.putExtra(FUAuthenticatorActivity.ARG_IS_ADDING_NEW_ACCOUNT, true);
+        intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);
+        final Bundle bundle = new Bundle();
+        bundle.putParcelable(AccountManager.KEY_INTENT, intent);
+        return bundle;
+    }
+
+    @Override
+    public Bundle confirmCredentials(AccountAuthenticatorResponse accountAuthenticatorResponse, Account account, Bundle bundle) throws NetworkErrorException {
+        return null;
+    }
+
+    @Override
+    public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
+
+        // Extract the username and password from the Account Manager, and ask
+        // the server for an appropriate AuthToken.
+        final AccountManager am = AccountManager.get(mContext);
+
+        String authToken = am.peekAuthToken(account, authTokenType);
+
+        // Lets give another try to authenticate the user
+        if (TextUtils.isEmpty(authToken)) {
+            final String password = am.getPassword(account);
+            if (password != null) {
+                try {
+                    authToken = new UserLoginTask(account.name, password, authTokenType, mContext).execute((Void) null).get();
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                } catch (ExecutionException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        // If we get an authToken - we return it
+        if (!TextUtils.isEmpty(authToken)) {
+            final Bundle result = new Bundle();
+            result.putString(AccountManager.KEY_ACCOUNT_NAME, account.name);
+            result.putString(AccountManager.KEY_ACCOUNT_TYPE, account.type);
+            result.putString(AccountManager.KEY_AUTHTOKEN, authToken);
+            return result;
+        }
+
+        // If we get here, then we couldn't access the user's password - so we
+        // need to re-prompt them for their credentials. We do that by creating
+        // an intent to display our AuthenticatorActivity.
+        final Intent intent = new Intent(mContext, FUAuthenticatorActivity.class);
+        intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);
+        intent.putExtra(FUAuthenticatorActivity.ARG_ACCOUNT_TYPE, account.type);
+        intent.putExtra(FUAuthenticatorActivity.ARG_AUTH_TYPE, authTokenType);
+        final Bundle bundle = new Bundle();
+        bundle.putParcelable(AccountManager.KEY_INTENT, intent);
+        return bundle;
+    }
+
+    @Override
+    public String getAuthTokenLabel(String s) {
+        return null;
+    }
+
+    @Override
+    public Bundle updateCredentials(AccountAuthenticatorResponse accountAuthenticatorResponse, Account account, String s, Bundle bundle) throws NetworkErrorException {
+        return null;
+    }
+
+    @Override
+    public Bundle hasFeatures(AccountAuthenticatorResponse accountAuthenticatorResponse, Account account, String[] strings) throws NetworkErrorException {
+        return null;
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/fulogin/FUAuthenticatorActivity.java

@@ -0,0 +1,281 @@
+package de.sebse.fuplanner.services.fulogin;
+
+import android.accounts.Account;
+import android.accounts.AccountAuthenticatorActivity;
+import android.accounts.AccountManager;
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.annotation.TargetApi;
+import android.app.LoaderManager.LoaderCallbacks;
+import android.content.Context;
+import android.content.CursorLoader;
+import android.content.Intent;
+import android.content.Loader;
+import android.content.pm.PackageManager;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Bundle;
+import android.provider.ContactsContract;
+import android.text.TextUtils;
+import android.view.View;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputMethodManager;
+import android.widget.Button;
+import android.widget.EditText;
+
+import androidx.annotation.NonNull;
+import de.sebse.fuplanner.R;
+
+import static de.sebse.fuplanner.services.fulogin.UserLoginTask.PARAM_USER_PASS;
+
+/**
+ * A login screen that offers login via email/password.
+ */
+public class FUAuthenticatorActivity extends AccountAuthenticatorActivity implements LoaderCallbacks<Cursor> {
+
+    /**
+     * Id to identity READ_CONTACTS permission request.
+     */
+    private static final int REQUEST_READ_CONTACTS = 0;
+
+    /**
+     * Keep track of the login task to ensure we can cancel it if requested.
+     */
+    UserLoginTask mAuthTask = null;
+
+    // UI references.
+    private EditText mEmailView;
+    EditText mPasswordView;
+    private View mProgressView;
+    private View mLoginFormView;
+
+
+
+    public static final String ARG_ACCOUNT_TYPE = "ARG_ACCOUNT_TYPE";
+    public static final String ARG_AUTH_TYPE = "ARG_AUTH_TYPE";
+    public static final String ARG_IS_ADDING_NEW_ACCOUNT = "ARG_IS_ADDING_NEW_ACCOUNT";
+    private String mAccountType;
+    private String mAuthTokenType;
+    private boolean mIsAddingNewAccount;
+
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        mAccountType = getIntent().getStringExtra(ARG_ACCOUNT_TYPE);
+        mAuthTokenType = getIntent().getStringExtra(ARG_AUTH_TYPE);
+        mIsAddingNewAccount = getIntent().getBooleanExtra(ARG_IS_ADDING_NEW_ACCOUNT, false);
+
+        setContentView(R.layout.activity_fu_authenticator);
+        // Set up the login form.
+        mEmailView = findViewById(R.id.input_username);
+        populateAutoComplete();
+
+        mPasswordView = findViewById(R.id.input_password);
+        mPasswordView.setOnEditorActionListener((textView, id, keyEvent) -> {
+            if (id == EditorInfo.IME_ACTION_DONE || id == EditorInfo.IME_NULL) {
+                attemptLogin();
+                return true;
+            }
+            return false;
+        });
+
+        Button mEmailSignInButton = findViewById(R.id.btn_login);
+        mEmailSignInButton.setOnClickListener(view -> attemptLogin());
+
+        mLoginFormView = findViewById(R.id.login_form);
+        mProgressView = findViewById(R.id.login_progress);
+    }
+
+    private void populateAutoComplete() {
+        if (!mayRequestContacts()) {
+            return;
+        }
+
+        getLoaderManager().initLoader(0, null, this);
+    }
+
+    private boolean mayRequestContacts() {
+        /*if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+            return true;
+        }
+        if (checkSelfPermission(READ_CONTACTS) == PackageManager.PERMISSION_GRANTED) {
+            return true;
+        }
+        if (shouldShowRequestPermissionRationale(READ_CONTACTS)) {
+            Snackbar.make(mEmailView, R.string.permission_rationale, Snackbar.LENGTH_INDEFINITE)
+                    .setAction(android.R.string.ok, new View.OnClickListener() {
+                        @Override
+                        @TargetApi(Build.VERSION_CODES.M)
+                        public void onClick(View v) {
+                            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
+                        }
+                    });
+        } else {
+            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
+        }*/
+        return false;
+    }
+
+    /**
+     * Callback received when a permissions request has been completed.
+     */
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
+                                           @NonNull int[] grantResults) {
+        if (requestCode == REQUEST_READ_CONTACTS) {
+            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                populateAutoComplete();
+            }
+        }
+    }
+
+
+    /**
+     * Attempts to sign in or register the account specified by the login form.
+     * If there are form errors (invalid email, missing fields, etc.), the
+     * errors are presented and no actual login attempt is made.
+     */
+    private void attemptLogin() {
+        InputMethodManager inputManager = (InputMethodManager) this.getSystemService(Context.INPUT_METHOD_SERVICE);
+        if (inputManager != null && getCurrentFocus() != null)
+            inputManager.hideSoftInputFromWindow(this.getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
+        if (mAuthTask != null) {
+            return;
+        }
+
+        // Reset errors.
+        mEmailView.setError(null);
+        mPasswordView.setError(null);
+
+        // Store values at the time of the login attempt.
+        String email = mEmailView.getText().toString();
+        String password = mPasswordView.getText().toString();
+
+        boolean cancel = false;
+        View focusView = null;
+
+        // Check for a valid password, if the user entered one.
+        if (!TextUtils.isEmpty(password) && !isPasswordValid(password)) {
+            mPasswordView.setError(getString(R.string.error_invalid_password));
+            focusView = mPasswordView;
+            cancel = true;
+        }
+
+        // Check for a valid email address.
+        if (TextUtils.isEmpty(email)) {
+            mEmailView.setError(getString(R.string.error_field_required));
+            focusView = mEmailView;
+            cancel = true;
+        }
+
+        if (cancel) {
+            // There was an error; don't attempt login and focus the first
+            // form field with an error.
+            focusView.requestFocus();
+        } else {
+            // Show a progress spinner, and kick off a background task to
+            // perform the user login attempt.
+            showProgress(true);
+            mAuthTask = new UserLoginTask(email, password, mAuthTokenType, this);
+            mAuthTask.execute((Void) null);
+        }
+    }
+
+    private boolean isPasswordValid(String password) {
+        //TODO: Replace this with your own logic
+        return password.length() > 4;
+    }
+
+    /**
+     * Shows the progress UI and hides the login form.
+     */
+    @TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
+    void showProgress(final boolean show) {
+        // On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
+        // for very easy animations. If available, use these APIs to fade-in
+        // the progress spinner.
+        int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);
+
+        mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+        mLoginFormView.animate().setDuration(shortAnimTime).alpha(
+                show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+            }
+        });
+
+        mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+        mProgressView.animate().setDuration(shortAnimTime).alpha(
+                show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+            }
+        });
+    }
+
+    @Override
+    public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
+        return new CursorLoader(this,
+                // Retrieve data rows for the device user's 'profile' contact.
+                Uri.withAppendedPath(ContactsContract.Profile.CONTENT_URI,
+                        ContactsContract.Contacts.Data.CONTENT_DIRECTORY), ProfileQuery.PROJECTION,
+
+                // Select only email addresses.
+                ContactsContract.Contacts.Data.MIMETYPE +
+                        " = ?", new String[]{ContactsContract.CommonDataKinds.Email
+                .CONTENT_ITEM_TYPE},
+
+                // Show primary email addresses first. Note that there won't be
+                // a primary email address if the user hasn't specified one.
+                ContactsContract.Contacts.Data.IS_PRIMARY + " DESC");
+    }
+
+    @Override
+    public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
+    }
+
+    @Override
+    public void onLoaderReset(Loader<Cursor> cursorLoader) {
+
+    }
+
+
+    private interface ProfileQuery {
+        String[] PROJECTION = {
+                ContactsContract.CommonDataKinds.Email.ADDRESS,
+                ContactsContract.CommonDataKinds.Email.IS_PRIMARY,
+        };
+
+        int ADDRESS = 0;
+        int IS_PRIMARY = 1;
+    }
+
+    void finishLogin(Intent intent) {
+        String accountName = intent.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
+        String accountPassword = intent.getStringExtra(PARAM_USER_PASS);
+        final Account account = new Account(accountName, intent.getStringExtra(AccountManager.KEY_ACCOUNT_TYPE));
+        final AccountManager mAccountManager = AccountManager.get(this);
+
+        if (getIntent().getBooleanExtra(ARG_IS_ADDING_NEW_ACCOUNT, false)) {
+            String authtoken = intent.getStringExtra(AccountManager.KEY_AUTHTOKEN);
+            String authtokenType = mAuthTokenType;
+
+            // Creating the account on the device and setting the auth token we got
+            // (Not setting the auth token will cause another call to the server to authenticate the user)
+            mAccountManager.addAccountExplicitly(account, accountPassword, null);
+            mAccountManager.setAuthToken(account, authtokenType, authtoken);
+        } else {
+            mAccountManager.setPassword(account, accountPassword);
+        }
+
+        setAccountAuthenticatorResult(intent.getExtras());
+        setResult(RESULT_OK, intent);
+        finish();
+    }
+}
+

app/src/main/java/de/sebse/fuplanner/services/fulogin/FUAuthenticatorService.java

@@ -0,0 +1,13 @@
+package de.sebse.fuplanner.services.fulogin;
+
+import android.app.Service;
+import android.content.Intent;
+import android.os.IBinder;
+
+public class FUAuthenticatorService extends Service {
+    @Override
+    public IBinder onBind(Intent intent) {
+        FUAuthenticator authenticator = new FUAuthenticator(this);
+        return authenticator.getIBinder();
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/fulogin/UserLoginTask.java

@@ -0,0 +1,124 @@
+package de.sebse.fuplanner.services.fulogin;
+
+import android.accounts.AccountManager;
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.content.Intent;
+import android.os.AsyncTask;
+import android.os.Build;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicReference;
+
+import androidx.annotation.Nullable;
+import de.sebse.fuplanner.R;
+import de.sebse.fuplanner.services.kvv.types.LoginToken;
+import de.sebse.fuplanner.services.kvv.sync.Login;
+import de.sebse.fuplanner.tools.logging.Logger;
+
+
+/**
+ * Represents an asynchronous login/registration task used to authenticate
+ * the user.
+ */
+public class UserLoginTask extends AsyncTask<Void, Void, String> {
+
+    /**
+     * A dummy authentication store containing known user names and passwords.
+     * TODO: remove after connecting to a real authentication system.
+     */
+    /*private static final String[] DUMMY_CREDENTIALS = new String[]{
+            "foo@example.com:hello", "bar@example.com:world"
+    };*/
+    static final String PARAM_USER_PASS = "PARAM_USER_PASS";
+
+    private final String mEmail;
+    private final String mPassword;
+    private final Login mVolleyLogin;
+    private String mTokenType;
+    private Logger log = new Logger(this);
+    @SuppressLint("StaticFieldLeak")
+    @Nullable
+    private FUAuthenticatorActivity mActivity;
+
+    UserLoginTask(String email, String password, String tokenType, @NotNull Context context) {
+        mEmail = email;
+        mPassword = password;
+        mTokenType = tokenType;
+        mVolleyLogin = new Login(context);
+        if (context instanceof FUAuthenticatorActivity)
+            mActivity = (FUAuthenticatorActivity) context;
+    }
+
+    @Override
+    protected String doInBackground(Void... params) {
+        // TODO: attempt authentication against a network service.
+
+        CountDownLatch latch = new CountDownLatch(1);
+        AtomicReference<LoginToken> login = new AtomicReference<>();
+        mVolleyLogin.doLogin(mEmail, mPassword, success -> {
+            mVolleyLogin.testLoginToken(success, success1 -> {
+                login.set(success);
+                latch.countDown();
+            }, error -> latch.countDown());
+        }, error -> latch.countDown());
+        try {
+            latch.await();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+
+        log.d(login.get());
+
+        if (login.get() == null) {
+            return null;
+        } else {
+            return login.get().toJsonString();
+        }
+
+        /*for (String credential : DUMMY_CREDENTIALS) {
+            String[] pieces = credential.split(":");
+            if (pieces[0].equals(mEmail)) {
+                // Account exists, return true if the password matches.
+                return pieces[1].equals(mPassword) ? "auth token here" : null;
+            }
+        }
+
+        // TODO: register the new account here.
+        return null;*/
+    }
+
+    @Override
+    protected void onPostExecute(final String success) {
+        if (mActivity == null || mActivity.isFinishing())
+            return;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1 && mActivity.isDestroyed())
+            return;
+        mActivity.mAuthTask = null;
+        mActivity.showProgress(false);
+
+        if (success != null) {
+            final Intent res = new Intent();
+            res.putExtra(AccountManager.KEY_ACCOUNT_NAME, mEmail);
+            res.putExtra(AccountManager.KEY_ACCOUNT_TYPE, AccountGeneral.ACCOUNT_TYPE);
+            res.putExtra(AccountManager.KEY_AUTHTOKEN, success);
+            res.putExtra(PARAM_USER_PASS, mPassword);
+            mActivity.finishLogin(res);
+        } else {
+            mActivity.mPasswordView.setError(mActivity.getString(R.string.error_incorrect_password));
+            mActivity.mPasswordView.requestFocus();
+        }
+    }
+
+    @Override
+    protected void onCancelled() {
+        if (mActivity == null || mActivity.isFinishing())
+            return;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1 && mActivity.isDestroyed())
+            return;
+        mActivity.mAuthTask = null;
+        mActivity.showProgress(false);
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/kvv/KVV.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 

app/src/main/java/de/sebse/fuplanner/services/kvv/KVVListener.java

@@ -0,0 +1,18 @@
+package de.sebse.fuplanner.services.kvv;
+
+import com.android.volley.NetworkResponse;
+
+import de.sebse.fuplanner.services.kvv.types.LoginToken;
+import de.sebse.fuplanner.tools.CustomAccountManager;
+
+public interface KVVListener {
+    default void onLogin(LoginToken token) {}
+
+    default void onLogout() {}
+
+    default void onModuleListChange() {}
+
+    default void onKVVNetworkResponse(NetworkResponse error) {}
+
+    CustomAccountManager getAccountManager();
+}

app/src/main/java/de/sebse/fuplanner/services/kvv/Login.java

@@ -0,0 +1,128 @@
+package de.sebse.fuplanner.services.kvv;
+
+import android.content.Context;
+
+import org.jetbrains.annotations.NotNull;
+
+import androidx.annotation.Nullable;
+import de.sebse.fuplanner.services.kvv.types.LoginToken;
+import de.sebse.fuplanner.services.fulogin.AccountGeneral;
+import de.sebse.fuplanner.tools.CustomAccountManager;
+import de.sebse.fuplanner.tools.NetworkCallbackCollector;
+import de.sebse.fuplanner.tools.network.HTTPService;
+import de.sebse.fuplanner.tools.network.NetworkCallback;
+import de.sebse.fuplanner.tools.network.NetworkError;
+import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
+
+public class Login extends HTTPService {
+    private final KVVListener mListener;
+    @Nullable private LoginToken mToken;
+    private boolean mLoginPending = false;
+    private final NetworkCallbackCollector<LoginToken> mRefreshCallbacks = new NetworkCallbackCollector<>();
+
+    Login(KVVListener listener, Context context) {
+        super(context);
+        this.mListener = listener;
+    }
+
+    public void restoreOnlineLogin(BooleanInterface callback) {
+        if (mLoginPending) {
+            callback.run(false);
+            return;
+        }
+        mLoginPending = true;
+        LoginToken.load(mListener.getAccountManager(), token -> {
+            boolean result = setToken(token);
+            mLoginPending = false;
+            log.d("loginToken", token != null ? token.toString() : null);
+            callback.run(result);
+        });
+    }
+
+    public void isOfflineStoredAvailable(BooleanInterface callback) {
+        LoginToken.load(mListener.getAccountManager(), token -> {
+            callback.run(token != null);
+        });
+    }
+
+    public boolean logout(boolean delete) {
+        if (mLoginPending)
+            return false;
+        if (mToken == null)
+            return true;
+        if (delete)
+            mToken.delete(mListener.getAccountManager());
+        mToken = null;
+        return handleCallbacks();
+    }
+
+    public boolean isLoginPending() {
+        return mLoginPending;
+    }
+
+    public boolean isLoggedIn() {
+        return mToken != null;
+    }
+
+    public boolean isInOnlineMode() {
+        return isLoggedIn();
+    }
+
+    void testLoginToken(@NotNull NetworkCallback<LoginToken> callback, @NotNull NetworkErrorCallback errorCallback) {
+        if (mToken == null) {
+            errorCallback.onError(new NetworkError(100173, -1, "Not logged in!"));
+            return;
+        }
+        testLoginToken(mToken, callback, errorCallback);
+    }
+
+    private void testLoginToken(@NotNull LoginToken token, @NotNull NetworkCallback<LoginToken> callback, @NotNull NetworkErrorCallback errorCallback) {
+        new de.sebse.fuplanner.services.kvv.sync.Login(getContext()).testLoginToken(token, callback, errorCallback);
+    }
+
+    @Nullable public LoginToken getLoginToken() {
+        return mToken;
+    }
+
+    void refreshLogin(NetworkCallback<LoginToken> success, NetworkErrorCallback error) {
+        boolean isFirst = mRefreshCallbacks.isEmpty();
+        mRefreshCallbacks.add(success, error);
+        if (!isFirst)
+            return;
+        CustomAccountManager manager = mListener.getAccountManager();
+        manager.doInvalidateToken(AccountGeneral.ACCOUNT_TYPE, AccountGeneral.AUTHTOKEN_TYPE_KVV, ignored -> {
+            restoreOnlineLogin(isRestored -> {
+                if (isRestored)
+                    testLoginToken(mRefreshCallbacks::responseResponse, mRefreshCallbacks::responseError);
+                else {
+                    logout(true);
+                    mRefreshCallbacks.responseError(new NetworkError(100180, 403, "Re-login failed!"));
+                }
+            });
+        });
+    }
+
+
+
+    private boolean handleCallbacks() {
+        if (mToken != null) {
+            mListener.onLogin(mToken);
+            return true;
+        } else {
+            mListener.onLogout();
+            return false;
+        }
+    }
+
+    private boolean setToken(@Nullable LoginToken token) {
+        if (token == null)
+            return false;
+        boolean isOnlyRefresh = mToken != null;
+        mToken = token;
+        return isOnlyRefresh || handleCallbacks();
+    }
+
+    public interface BooleanInterface {
+        void run(boolean bool);
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/kvv/Modules.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 
@@ -10,7 +10,7 @@ public class Modules {
     private final HashMap<String, Part> mAddons = new HashMap<>();
     private ModulesList mList = null;
     private final Login mLogin;
-    private KVVListener mListener;
+    private final KVVListener mListener;
     private final Context context;
 
     Modules(Login login, KVVListener listener, Context context) {

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesAnnouncements.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 
@@ -8,8 +8,8 @@ import org.json.JSONObject;
 
 import java.util.ArrayList;
 
-import de.sebse.fuplanner.services.KVV.types.Announcement;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Announcement;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesAssignments.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 
@@ -8,9 +8,9 @@ import org.json.JSONObject;
 
 import java.util.ArrayList;
 
-import de.sebse.fuplanner.services.KVV.types.Assignment;
-import de.sebse.fuplanner.services.KVV.types.AssignmentList;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Assignment;
+import de.sebse.fuplanner.services.kvv.types.AssignmentList;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesDetails.java

@@ -1,11 +1,11 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 import android.util.Pair;
 
 import java.util.concurrent.atomic.AtomicReference;
 
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesEvents.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 
@@ -6,9 +6,9 @@ import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import de.sebse.fuplanner.services.KVV.types.Event;
-import de.sebse.fuplanner.services.KVV.types.EventList;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Event;
+import de.sebse.fuplanner.services.kvv.types.EventList;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesGradebook.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 
@@ -8,8 +8,8 @@ import org.json.JSONObject;
 
 import java.util.ArrayList;
 
-import de.sebse.fuplanner.services.KVV.types.Grade;
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Grade;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesList.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 
@@ -13,9 +13,9 @@ import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.regex.MatchResult;
 
-import de.sebse.fuplanner.services.KVV.types.Lecturer;
-import de.sebse.fuplanner.services.KVV.types.Modules;
-import de.sebse.fuplanner.services.KVV.types.Semester;
+import de.sebse.fuplanner.services.kvv.types.Lecturer;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Semester;
 import de.sebse.fuplanner.tools.NewAsyncQueue;
 import de.sebse.fuplanner.tools.Regex;
 import de.sebse.fuplanner.tools.network.HTTPService;
@@ -23,13 +23,13 @@ import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
 
-import static de.sebse.fuplanner.services.KVV.PartModules.RETRY_COUNT;
+import static de.sebse.fuplanner.services.kvv.PartModules.RETRY_COUNT;
 
 public class ModulesList extends HTTPService {
     private final Login mLogin;
     private final KVVListener mListener;
     @Nullable private Modules mModules;
-    private NewAsyncQueue mQueue = new NewAsyncQueue();
+    private final NewAsyncQueue mQueue = new NewAsyncQueue();
 
     ModulesList(Login login, KVVListener listener, Context context) {
         super(context);
@@ -51,7 +51,7 @@ public class ModulesList extends HTTPService {
     }
 
     private void find(String moduleID, NetworkCallback<Modules.Module> moduleNetworkCallback, NetworkErrorCallback errorCallback, int retries) {
-        if (mModules != null && mLogin.getLoginToken() != null && !mLogin.getLoginToken().isSameUser(mModules.getUsername()))
+        if (mModules != null && mLogin.getLoginToken() != null && mLogin.getLoginToken().isOtherUser(mModules.getUsername()))
             delete();
         if (retries < 0) {
             errorCallback.onError(new NetworkError(101107, -1, "Too many retries!"));
@@ -104,7 +104,7 @@ public class ModulesList extends HTTPService {
     }
 
     private void recv(final NetworkCallback<Modules> callback, final NetworkErrorCallback errorCallback, boolean forceRefresh, final int retries) {
-        if (mModules != null && mLogin.getLoginToken() != null && !mLogin.getLoginToken().isSameUser(mModules.getUsername()))
+        if (mModules != null && mLogin.getLoginToken() != null && mLogin.getLoginToken().isOtherUser(mModules.getUsername()))
             delete();
         mQueue.add(() -> {
             if (this.mModules != null && !forceRefresh) {
@@ -115,10 +115,10 @@ public class ModulesList extends HTTPService {
             this.upgrade(success -> {
                 if (this.mModules == null)
                     this.mModules = success;
-                else
-                    this.mModules.updateList(success);
-                mListener.onModuleListChange();
-                store();
+                else if (this.mModules.updateList(success)) {
+                    mListener.onModuleListChange();
+                    store();
+                }
                 callback.onResponse(this.mModules);
                 mQueue.next();
             }, error -> {
@@ -139,6 +139,7 @@ public class ModulesList extends HTTPService {
     }
 
     private void upgrade(final NetworkCallback<Modules> callback, final NetworkErrorCallback errorCallback) {
+        log.d(mLogin.isInOnlineMode(), mLogin.getLoginToken());
         if (!mLogin.isInOnlineMode() || mLogin.getLoginToken() == null) {
             errorCallback.onError(new NetworkError(101105, 500, "Currently running in offline mode!"));
             return;
@@ -163,6 +164,8 @@ public class ModulesList extends HTTPService {
                 try {
                     JSONObject site = sites.getJSONObject(i);
                     String semester_string = site.getJSONObject("props").optString("term_eid", null);
+                    if (semester_string == null)
+                        continue;
                     Semester semester = new Semester(semester_string);
                     HashSet<String> lvNumbers = new HashSet<>();
                     String kvv_lvnumbers = site.getJSONObject("props").optString("kvv_lvnumbers", null);

app/src/main/java/de/sebse/fuplanner/services/kvv/ModulesResources.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 import android.os.Environment;
@@ -11,9 +11,10 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.util.ArrayList;
 
-import de.sebse.fuplanner.services.KVV.types.Modules;
-import de.sebse.fuplanner.services.KVV.types.Resource;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Resource;
 import de.sebse.fuplanner.tools.Regex;
+import de.sebse.fuplanner.tools.UtilsDate;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
@@ -64,7 +65,8 @@ public class ModulesResources extends PartModules<ArrayList<Resource>> {
                     JSONObject site = sites.getJSONObject(i);
                     String author = site.getString("author");
                     String title = site.getString("title");
-                    long modifiedDate = site.getLong("modifiedDate");
+                    //long modifiedDate = site.getLong("modifiedDate");"20181018155405439"
+                    long modifiedDate = UtilsDate.stringToMillis(site.getString("modifiedDate"), "yyyyMMddHHmmssSSS");
                     String url = site.getString("url");
                     boolean visible = site.getBoolean("visible");
                     String type = site.getString("type");
@@ -124,7 +126,7 @@ public class ModulesResources extends PartModules<ArrayList<Resource>> {
         file(filename, url, modulename, callback, errorCallback, forceRefresh, RETRY_COUNT);
     }
 
-    public void file(final String filename, final String url, final String modulename, final NetworkCallback<String> callback, final NetworkErrorCallback errorCallback, boolean forceRefresh, int retries) {
+    private void file(final String filename, final String url, final String modulename, final NetworkCallback<String> callback, final NetworkErrorCallback errorCallback, boolean forceRefresh, int retries) {
         if (isExternalStorageReadable()){
             File f = new File(Environment.getExternalStoragePublicDirectory(
                     Environment.DIRECTORY_DOWNLOADS)+"/"+modulename+"/"+filename);

app/src/main/java/de/sebse/fuplanner/services/kvv/Part.java

@@ -1,16 +1,16 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.network.HTTPService;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
 
 public abstract class Part<T> extends HTTPService {
     static final int RETRY_COUNT = 1;
-    protected final Login mLogin;
-    protected final ModulesList mList;
+    final Login mLogin;
+    final ModulesList mList;
 
     Part(Login login, ModulesList list, Context context) {
         super(context);

app/src/main/java/de/sebse/fuplanner/services/kvv/PartModules.java

@@ -1,17 +1,17 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv;
 
 import android.content.Context;
 import android.os.Build;
 import android.text.Html;
 import android.text.Spanned;
 
-import de.sebse.fuplanner.services.KVV.types.Modules;
+import de.sebse.fuplanner.services.kvv.types.Modules;
 import de.sebse.fuplanner.tools.NewAsyncQueue;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
 
 abstract class PartModules<T> extends Part<Modules.Module> {
-    private NewAsyncQueue mQueue = new NewAsyncQueue();
+    private final NewAsyncQueue mQueue = new NewAsyncQueue();
 
     PartModules(Login login, ModulesList list, Context context) {
         super(login, list, context);

app/src/main/java/de/sebse/fuplanner/services/kvv/sync/KVVContentProvider.java

@@ -0,0 +1,67 @@
+package de.sebse.fuplanner.services.kvv.sync;
+
+import android.content.ContentProvider;
+import android.content.ContentValues;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.net.Uri;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+public class KVVContentProvider extends ContentProvider {
+
+    private static final String PROVIDER_NAME = "de.sebse.fuplanner.contentprovider.kvv.modules";
+    private static final Uri CONTENT_URI = Uri.parse("content://" + PROVIDER_NAME + "/modules");
+    private static final int MODULE = 1;
+    private static final int MODULE_ID = 2;
+    private static final UriMatcher uriMatcher = getUriMatcher();
+
+    private static UriMatcher getUriMatcher() {
+        UriMatcher uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+        uriMatcher.addURI(PROVIDER_NAME, "modules", MODULE);
+        uriMatcher.addURI(PROVIDER_NAME, "modules/#", MODULE_ID);
+        return uriMatcher;
+    }
+
+
+    @Override
+    public boolean onCreate() {
+        return true;
+    }
+
+    @Nullable
+    @Override
+    public Cursor query(@NonNull Uri uri, @Nullable String[] strings, @Nullable String s, @Nullable String[] strings1, @Nullable String s1) {
+        return null;
+    }
+
+    @Nullable
+    @Override
+    public String getType(@NonNull Uri uri) {
+        switch (uriMatcher.match(uri)) {
+            case MODULE:
+                return "vnd.android.cursor.dir/vnd.com."+PROVIDER_NAME;
+            case MODULE_ID:
+                return "vnd.android.cursor.item/vnd.com."+PROVIDER_NAME;
+
+        }
+        return null;
+    }
+
+    @Nullable
+    @Override
+    public Uri insert(@NonNull Uri uri, @Nullable ContentValues contentValues) {
+        return null;
+    }
+
+    @Override
+    public int delete(@NonNull Uri uri, @Nullable String s, @Nullable String[] strings) {
+        return 0;
+    }
+
+    @Override
+    public int update(@NonNull Uri uri, @Nullable ContentValues contentValues, @Nullable String s, @Nullable String[] strings) {
+        return 0;
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/kvv/sync/KVVSyncAdapter.java

@@ -0,0 +1,87 @@
+package de.sebse.fuplanner.services.kvv.sync;
+
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.content.AbstractThreadedSyncAdapter;
+import android.content.ContentProviderClient;
+import android.content.Context;
+import android.content.SyncResult;
+import android.os.Bundle;
+
+import com.android.volley.NetworkResponse;
+
+import java.util.Iterator;
+
+import de.sebse.fuplanner.services.kvv.KVV;
+import de.sebse.fuplanner.services.kvv.KVVListener;
+import de.sebse.fuplanner.services.kvv.types.LoginToken;
+import de.sebse.fuplanner.services.kvv.types.Modules;
+import de.sebse.fuplanner.tools.CustomAccountManager;
+import de.sebse.fuplanner.tools.logging.Logger;
+
+public class KVVSyncAdapter extends AbstractThreadedSyncAdapter {
+    private KVV mKVV;
+    private Logger log = new Logger(this);
+
+    /**
+     * Set up the sync adapter
+     */
+    public KVVSyncAdapter(Context context, boolean autoInitialize) {
+        super(context, autoInitialize);
+        init(context);
+    }
+    /**
+     * Set up the sync adapter. This form of the
+     * constructor maintains compatibility with Android 3.0
+     * and later platform versions
+     */
+    public KVVSyncAdapter(
+            Context context,
+            boolean autoInitialize,
+            boolean allowParallelSyncs) {
+        super(context, autoInitialize, allowParallelSyncs);
+        init(context);
+    }
+
+    private void init(Context context) {
+        mKVV = new KVV(new KVVListener() {
+            CustomAccountManager accountManager = null;
+            @Override
+            public CustomAccountManager getAccountManager() {
+                if (accountManager == null)
+                    accountManager = new CustomAccountManager(AccountManager.get(context), () -> null);
+                return accountManager;
+            }
+        }, context);
+        mKVV.account().restoreOnlineLogin(bool -> {});
+    }
+
+    /*
+     * Specify the code you want to run in the sync adapter. The entire
+     * sync adapter runs in a background thread, so you don't have to set
+     * up your own background processing.
+     */
+    @Override
+    public void onPerformSync(
+            Account account,
+            Bundle extras,
+            String authority,
+            ContentProviderClient provider,
+            SyncResult syncResult) {
+        log.d("start syncing");
+        /*
+         * Put the data transfer code here.
+         */
+        mKVV.modules().list().recv(success -> {
+            Iterator<Modules.Module> iterator = success.latestSemesterIterator();
+            while (iterator.hasNext()) {
+                Modules.Module module = iterator.next();
+                log.d("sync module", module.title);
+                mKVV.modules().details().recv(module, success1 -> {
+                    if (success1.second)
+                        log.d("Sync Successful for Module '"+module.title+"'!");
+                }, log::e, true);
+            }
+        }, log::e, true);
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/kvv/sync/KVVSyncService.java

@@ -0,0 +1,24 @@
+package de.sebse.fuplanner.services.kvv.sync;
+
+import android.app.Service;
+import android.content.Intent;
+import android.os.IBinder;
+
+public class KVVSyncService extends Service {
+
+    private static final Object sSyncAdapterLock = new Object();
+    private static KVVSyncAdapter sSyncAdapter = null;
+
+    @Override
+    public void onCreate() {
+        synchronized (sSyncAdapterLock) {
+            if (sSyncAdapter == null)
+                sSyncAdapter = new KVVSyncAdapter(getApplicationContext(), true);
+        }
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return sSyncAdapter.getSyncAdapterBinder();
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/kvv/sync/Login.java

@@ -1,130 +1,28 @@
-package de.sebse.fuplanner.services.KVV;
+package de.sebse.fuplanner.services.kvv.sync;
 
 import android.content.Context;
 
-
 import org.jetbrains.annotations.NotNull;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import java.io.FileNotFoundException;
-import java.io.IOException;
 import java.util.HashMap;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import androidx.annotation.Nullable;
-import de.sebse.fuplanner.services.KVV.types.LoginToken;
+import de.sebse.fuplanner.services.kvv.types.LoginToken;
 import de.sebse.fuplanner.tools.network.HTTPService;
 import de.sebse.fuplanner.tools.network.NetworkCallback;
 import de.sebse.fuplanner.tools.network.NetworkError;
 import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
 
 public class Login extends HTTPService {
-    private KVVListener mListener;
-    @Nullable private LoginToken mToken;
-    private boolean mLoginPending = false;
-    private boolean mOnlineMode = false;
-
-    Login(KVVListener listener, Context context) {
+    public Login(Context context) {
         super(context);
-        this.mListener = listener;
     }
 
-    public void doOnlineLogin(@NotNull String username, @NotNull String password, NetworkCallback<LoginToken> callback, NetworkErrorCallback errorCallback) {
-        if (mLoginPending) {
-            errorCallback.onError(new NetworkError(100160, -1, "Login already pending!"));
-        }
-        mLoginPending = true;
-        doLogin(username, password, token -> {
-            testLoginToken(token, token2 -> {
-                setToken(token2, true);
-                mLoginPending = false;
-                callback.onResponse(token2);
-            }, error -> {
-                mLoginPending = false;
-                errorCallback.onError(error);
-            });
-        }, error -> {
-            mLoginPending = false;
-            errorCallback.onError(error);
-        });
-    }
 
-    public boolean restoreOnlineLogin() {
-        return restoreLogin(true);
-    }
-
-    public boolean doOfflineLogin() {
-        return restoreLogin(false);
-    }
-
-    private boolean restoreLogin(boolean enteringOnlineMode) {
-        if (mLoginPending || mToken != null)
-            return false;
-        mLoginPending = true;
-        boolean result = false;
-        try {
-            result = setToken(LoginToken.load(getContext()), enteringOnlineMode);
-        } catch (FileNotFoundException ignored) {
-        } catch (IOException e) {
-            e.printStackTrace();
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        }
-        mLoginPending = false;
-        return result;
-    }
-
-    public boolean isOfflineStoredAvailable() {
-        try {
-            LoginToken load = LoginToken.load(getContext());
-            return load != null;
-        } catch (FileNotFoundException ignored) {
-        } catch (IOException e) {
-            e.printStackTrace();
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        }
-        return false;
-    }
-
-    public boolean logout(boolean delete) {
-        if (mLoginPending)
-            return false;
-        if (mToken == null)
-            return true;
-        if (delete)
-            mToken.delete(getContext());
-        mToken = null;
-        return handleCallbacks();
-    }
-
-    public boolean isLoginPending() {
-        return mLoginPending;
-    }
-
-    public boolean isLoggedIn() {
-        return mToken != null;
-    }
-
-    public boolean isInOfflineMode() {
-        return isLoggedIn() && !mOnlineMode;
-    }
-
-    public boolean isInOnlineMode() {
-        return isLoggedIn() && mOnlineMode;
-    }
-
-    void testLoginToken(@NotNull NetworkCallback<LoginToken> callback, @NotNull NetworkErrorCallback errorCallback) {
-        if (mToken == null) {
-            errorCallback.onError(new NetworkError(100173, -1, "Not logged in!"));
-            return;
-        }
-        testLoginToken(mToken, callback, errorCallback);
-    }
-
-    private void testLoginToken(@NotNull LoginToken token, @NotNull NetworkCallback<LoginToken> callback, @NotNull NetworkErrorCallback errorCallback) {
+    public void testLoginToken(@NotNull LoginToken token, @NotNull NetworkCallback<LoginToken> callback, @NotNull NetworkErrorCallback errorCallback) {
         get(String.format("https://kvv.imp.fu-berlin.de/direct/profile/%s.json", token.getUsername()), token.getCookies(), response -> {
             String body = response.getParsed();
             if (body == null) {
@@ -143,46 +41,6 @@ public class Login extends HTTPService {
         }, error -> errorCallback.onError(new NetworkError(100170, error.networkResponse.statusCode, "Testing login failed!")));
     }
 
-    @Nullable public LoginToken getLoginToken() {
-        return mToken;
-    }
-
-    void refreshLogin(NetworkCallback<LoginToken> success, NetworkErrorCallback error) {
-        mListener.getCredentials(credentials -> {
-            doOnlineLogin(credentials.getUsername(), credentials.getPassword(), success, error);
-        }, e -> {
-            logout(false);
-            error.onError(e);
-        });
-    }
-
-
-
-    private boolean handleCallbacks() {
-        if (mToken != null) {
-            mListener.onLogin(mToken, mOnlineMode);
-            return true;
-        } else {
-            mListener.onLogout();
-            return false;
-        }
-    }
-
-    private boolean setToken(@Nullable LoginToken token, boolean enteringOnlineMode) {
-        if (token == null)
-            return false;
-        boolean isOnlyRefresh = mToken != null;
-        mToken = token;
-        if (enteringOnlineMode) {
-            try {
-                mToken.save(getContext());
-            } catch (IOException e) {
-                e.printStackTrace();
-            }
-        }
-        mOnlineMode = enteringOnlineMode;
-        return isOnlyRefresh || handleCallbacks();
-    }
 
 
 
@@ -193,7 +51,11 @@ public class Login extends HTTPService {
 
 
 
-    private void doLogin(String username, String password, NetworkCallback<LoginToken> callback, NetworkErrorCallback error) {
+
+
+
+
+    public void doLogin(String username, String password, NetworkCallback<LoginToken> callback, NetworkErrorCallback error) {
         startKVVSession(success -> {
             String kvvJSESSIONID = success.get("JSESSIONID");
             getSAMLRequest(kvvJSESSIONID, success1 -> startIdentSession(success1.get("Location"), success11 -> {

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Announcement.java

@@ -1,11 +1,17 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
-import java.util.ArrayList;
+import org.json.JSONException;
+import org.json.JSONObject;
 
-public class Announcement implements Serializable {
+import java.util.ArrayList;
+import java.util.HashSet;
+
+import androidx.annotation.NonNull;
+import de.sebse.fuplanner.tools.UtilsJson;
+
+public class Announcement implements UtilsJson.JsonConvertible {
     private final String id;
     private final String title;
     private final String body;
@@ -14,7 +20,6 @@ public class Announcement implements Serializable {
     private final ArrayList<String> urls;
 
     public Announcement(String id, String title, String body, String createdBy, long createdOn, ArrayList<String> urls) {
-
         this.id = id;
         this.title = title;
         this.body = body;
@@ -23,6 +28,19 @@ public class Announcement implements Serializable {
         this.urls = urls;
     }
 
+    public Announcement(JSONObject json) throws JSONException {
+        this.id = json.getString("id");
+        this.title = json.getString("title");
+        this.body = json.getString("body");
+        this.createdBy = json.getString("createdBy");
+        this.createdOn = json.getLong("createdOn");
+        ArrayList<String> urls = new ArrayList<>();
+        for (String url: UtilsJson.jsonArrayToIterableString(json.getJSONArray("urls"))) {
+            urls.add(url);
+        }
+        this.urls = urls;
+    }
+
     public ArrayList<String> getUrls() {
         return urls;
     }
@@ -47,6 +65,7 @@ public class Announcement implements Serializable {
         return createdOn;
     }
 
+    @NonNull
     @Override
     public String toString() {
         return "ID: "+getId()+
@@ -61,4 +80,16 @@ public class Announcement implements Serializable {
     public int hashCode() {
         return Objects.hashCode(getId(), getBody(), getCreatedBy(), getCreatedOn(), getTitle(), getUrls());
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("id", id);
+        json.put("title", title);
+        json.put("body", body);
+        json.put("createdBy", createdBy);
+        json.put("createdOn", createdOn);
+        json.put("urls", UtilsJson.collectionToJson(urls));
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Assignment.java

@@ -1,11 +1,16 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.util.ArrayList;
 
-public class Assignment implements Serializable {
+import androidx.annotation.NonNull;
+import de.sebse.fuplanner.tools.UtilsJson;
+
+public class Assignment implements UtilsJson.JsonConvertible {
     private final String id;
     private final String title;
     private final long dueTime;
@@ -44,6 +49,7 @@ public class Assignment implements Serializable {
         return instructions;
     }
 
+    @NonNull
     @Override
     public String toString() {
         return "ID: "+getId()+
@@ -56,4 +62,15 @@ public class Assignment implements Serializable {
     public int hashCode() {
         return Objects.hashCode(getId(), getDueDate(), getInstructions(), getTitle(), getUrls());
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("id", id);
+        json.put("title", title);
+        json.put("dueTime", dueTime);
+        json.put("createdBy", UtilsJson.collectionToJson(urls));
+        json.put("instructions", instructions);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/AssignmentList.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
 import de.sebse.fuplanner.tools.DateSortedList;
 

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Event.java

@@ -1,15 +1,19 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
+import androidx.annotation.NonNull;
 import de.sebse.fuplanner.tools.ColorRGB;
+import de.sebse.fuplanner.tools.UtilsJson;
 
-public class Event implements Serializable {
+public class Event implements UtilsJson.JsonConvertible {
     private final String siteId;
     private final String id;
     private final String type;
@@ -106,6 +110,7 @@ public class Event implements Serializable {
         }
     }
 
+    @NonNull
     @Override
     public String toString() {
         return "ID: "+getId()+
@@ -118,4 +123,17 @@ public class Event implements Serializable {
     public int hashCode() {
         return Objects.hashCode(getId(), getType(), getStartDate(), getEndDate(), getTitle(), getLocation());
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("siteId", siteId);
+        json.put("id", id);
+        json.put("type", type);
+        json.put("title", title);
+        json.put("duration", duration);
+        json.put("firstTime", firstTime);
+        json.put("location", location);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/EventList.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
 import de.sebse.fuplanner.tools.DateSortedList;
 

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Grade.java

@@ -1,10 +1,14 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
 
-public class Grade implements Serializable {
+import androidx.annotation.NonNull;
+import de.sebse.fuplanner.tools.UtilsJson;
+
+public class Grade implements UtilsJson.JsonConvertible {
     private final String itemName;
     private final double grade;
     private final double maxPoints;
@@ -27,6 +31,7 @@ public class Grade implements Serializable {
         return itemName;
     }
 
+    @NonNull
     @Override
     public String toString() {
         return "Name: "+getItemName()+
@@ -38,4 +43,13 @@ public class Grade implements Serializable {
     public int hashCode() {
         return Objects.hashCode(getItemName(), getPoints(), getMaxPoints());
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("itemName", itemName);
+        json.put("grade", grade);
+        json.put("maxPoints", maxPoints);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/GroupedEvents.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
 
 import android.annotation.SuppressLint;
@@ -9,36 +9,41 @@ import java.util.Collections;
 import java.util.List;
 
 import androidx.annotation.NonNull;
-import de.sebse.fuplanner.tools.logging.Logger;
 
-public class GroupedEvents {
-    private ArrayList<Group> arrayList = new ArrayList<>();
-    private Logger log = new Logger(this);
+public class GroupedEvents extends EventList {
+    private final ArrayList<Group> arrayList = new ArrayList<>();
+    private int skippedDayCount = 0;
 
-    public void add(Event event) {
+    public boolean add(Event event) {
+        boolean result = super.add(event);
         Calendar calendar = Calendar.getInstance();
         calendar.setTimeInMillis(event.getStartDate());
         long dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK);
         for (Group group : arrayList) {
             if (group.add(event)) {
-                return;
+                return result;
             }
         }
         arrayList.add(new Group(event));
+        return result;
     }
 
     public List<Group> getGroups() {
         return Collections.unmodifiableList(arrayList);
     }
 
+    public int getSkippedDayCount() {
+        return skippedDayCount;
+    }
+
     public class Group {
         private long firstDate;
         private long lastDate;
-        private ArrayList<Long> skippedDates;
+        private final ArrayList<Long> skippedDates;
 
-        private int dayOfWeek;
-        private long startTime;
-        private long duration;
+        private final int dayOfWeek;
+        private final long startTime;
+        private final long duration;
 
         private Group(Event event) {
             Calendar calendar = Calendar.getInstance();
@@ -73,16 +78,19 @@ public class GroupedEvents {
                 firstDate = addDays(firstDate, -7);
                 while (firstDate > date) {
                     skippedDates.add(firstDate);
+                    skippedDayCount += 1;
                     firstDate = addDays(firstDate, -7);
                 }
             } else if (date > lastDate) {
                 lastDate = addDays(lastDate, 7);
                 while (lastDate < date) {
                     skippedDates.add(lastDate);
+                    skippedDayCount += 1;
                     lastDate = addDays(lastDate, 7);
                 }
             } else {
                 skippedDates.remove(date);
+                skippedDayCount -= 1;
             }
             return true;
         }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Lecturer.java

@@ -1,10 +1,17 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
+
+import com.google.android.gms.common.internal.Objects;
+
+import org.json.JSONException;
+import org.json.JSONObject;
 
-import java.io.Serializable;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-public class Lecturer implements Serializable {
+import androidx.annotation.NonNull;
+import de.sebse.fuplanner.tools.UtilsJson;
+
+public class Lecturer implements UtilsJson.JsonConvertible {
     private final String firstName;
     private final String surname;
     private final String mail;
@@ -22,6 +29,13 @@ public class Lecturer implements Serializable {
         this.isResponsible = matcher.group(4).equals("true");
     }
 
+    public Lecturer(JSONObject json) throws JSONException {
+        this.firstName = json.getString("firstName");
+        this.surname = json.getString("surname");
+        this.mail = json.getString("mail");
+        this.isResponsible = json.getBoolean("isResponsible");
+    }
+
     public String getFirstName() {
         return firstName;
     }
@@ -46,10 +60,26 @@ public class Lecturer implements Serializable {
         return getFirstName().substring(0, 1) + ". " + getSurname();
     }
 
+    @NonNull
     @Override
     public String toString() {
         return "First name: "+ getFirstName()+
                 "\nSurname: "+getSurname()+
                 "\nMail: "+getMail();
     }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(getFirstName(), getSurname(), getMail(), isResponsible());
+    }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("firstName", firstName);
+        json.put("surname", surname);
+        json.put("mail", mail);
+        json.put("isResponsible", isResponsible);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/LoginToken.java

@@ -0,0 +1,148 @@
+package de.sebse.fuplanner.services.kvv.types;
+
+import android.content.Context;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.util.HashMap;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import de.sebse.fuplanner.services.fulogin.AccountGeneral;
+import de.sebse.fuplanner.tools.CustomAccountManager;
+import de.sebse.fuplanner.tools.logging.Logger;
+
+/**
+ * Created by sebastian on 29.10.17.
+ */
+
+public class LoginToken {
+    private final String username;
+    private final String shibsessionKey;
+    private final String shibsessionName;
+    private final String JSESSIONID;
+    @Nullable private String fullName;
+    @Nullable private String email;
+
+    public LoginToken(String username, String shibsessionKey, String shibsessionName, String JSESSIONID) {
+        this.username = username;
+        this.shibsessionKey = shibsessionKey;
+        this.shibsessionName = shibsessionName;
+        this.JSESSIONID = JSESSIONID;
+    }
+
+    @Nullable
+    public static void load(CustomAccountManager manager, LoginTokenInterface callback) {
+        if (!manager.hasAccounts(AccountGeneral.ACCOUNT_TYPE)) {
+            callback.run(null);
+            return;
+        }
+        manager.getTokenByType(AccountGeneral.ACCOUNT_TYPE, AccountGeneral.AUTHTOKEN_TYPE_KVV, tokenString -> {
+            if (tokenString == null) {
+                callback.run(null);
+                return;
+            }
+            callback.run(LoginToken.fromJsonString(tokenString));
+        });
+    }
+
+    public void delete(CustomAccountManager manager) {
+        manager.deleteAccount(AccountGeneral.ACCOUNT_TYPE);
+    }
+
+    public void setAdditionals(String fullName, String email) {
+        this.fullName = fullName;
+        this.email = email;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    private String getShibsessionKey() {
+        return shibsessionKey;
+    }
+
+    private String getShibsessionName() {
+        return shibsessionName;
+    }
+
+    private String getJSESSIONID() {
+        return JSESSIONID;
+    }
+
+    @Nullable
+    public String getFullName() {
+        return fullName;
+    }
+
+    @Nullable
+    public String getEmail() {
+        return email;
+    }
+
+    public HashMap<String, String> getCookies() {
+        HashMap<String, String> cookies = new HashMap<>();
+        cookies.put("JSESSIONID", getJSESSIONID());
+        cookies.put(getShibsessionKey(), getShibsessionName());
+        cookies.put("pasystem_timezone_ok", "true");
+        return cookies;
+    }
+
+    public boolean isOtherUser(String username) {
+        return !this.getUsername().equals(username);
+    }
+
+    @NonNull
+    @Override
+    public String toString() {
+        StringBuilder result = new StringBuilder();
+        HashMap<String, String> cookies = this.getCookies();
+        for (String header: cookies.keySet()) {
+            result.append(header).append("=").append(cookies.get(header)).append(";");
+        }
+        return result.substring(0, result.length()-1);
+    }
+
+    public String toJsonString() {
+        JSONObject json = new JSONObject();
+        try {
+            json.put("username", username);
+            json.put("shibsessionKey", shibsessionKey);
+            json.put("shibsessionName", shibsessionName);
+            json.put("JSESSIONID", JSESSIONID);
+            json.put("fullName", fullName);
+            json.put("email", email);
+        } catch (JSONException e) {
+            return null;
+        }
+        return json.toString();
+    }
+
+    public static LoginToken fromJsonString(String tokenString) {
+        try {
+            JSONObject json = new JSONObject(tokenString);
+            LoginToken token = new LoginToken(
+                    json.getString("username"),
+                    json.getString("shibsessionName"),
+                    json.getString("shibsessionName"),
+                    json.getString("JSESSIONID"));
+            if (!json.isNull("fullName"))
+                token.setAdditionals(
+                        json.getString("fullName"),
+                        json.getString("email")
+                );
+            return token;
+        } catch (JSONException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    public interface LoginTokenInterface {
+        void run(LoginToken token);
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Modules.java

@@ -0,0 +1,317 @@
+package de.sebse.fuplanner.services.kvv.types;
+
+import android.content.Context;
+
+import com.google.android.gms.common.internal.Objects;
+
+import org.jetbrains.annotations.NotNull;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.BufferedReader;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.OutputStreamWriter;
+import java.lang.reflect.Array;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import de.sebse.fuplanner.tools.UtilsJson;
+
+import static de.sebse.fuplanner.tools.UtilsJson.collectionToJson;
+import static de.sebse.fuplanner.tools.UtilsJson.jsonArrayToIterableObject;
+
+/**
+ * Created by sebastian on 29.10.17.
+ */
+
+public class Modules implements Iterable<Modules.Module> {
+    private SortedListModule list;
+    private final String mUsername;
+    private long mLoadTime;
+    //private transient Logger log = new Logger(this);
+    private static final String FILE_NAME = "ModuleListSaving";
+    private static final String FILE_NAME_TIMESTAMP = "ModuleListSavingTimestamp";
+
+    public Modules(String username) {
+        this.mUsername = username;
+        this.list = new SortedListModule();
+    }
+
+    public void addModule(@Nullable Semester semester, HashSet<String> lvNumber, String title, LinkedHashSet<Lecturer> lecturer, String type, String description, String ID) {
+        Module m = new Module(semester, lvNumber, title, lecturer, type, description, ID);
+        this.list.add(m);
+    }
+
+    @NonNull
+    @Override
+    public String toString() {
+        return this.list.toString();
+    }
+
+    @NonNull
+    @Override
+    public Iterator<Module> iterator() {
+        return this.list.iterator();
+    }
+
+    public Iterator<Module> latestSemesterIterator() {
+        return this.list.filteredIterator(this.list.getLatestSemester());
+    }
+
+    public int size() {
+        return this.list.size();
+    }
+
+    public Module get(String id) {
+        return this.list.getById(id);
+    }
+
+    public Module getByIndex(int index) {
+        return this.list.get(index);
+    }
+
+    public static Modules load(Context context) throws IOException {
+        String ret = "";
+        InputStream inputStream = context.openFileInput(FILE_NAME);
+        if (inputStream != null) {
+            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
+            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
+            String receiveString;
+            StringBuilder stringBuilder = new StringBuilder();
+            while ((receiveString = bufferedReader.readLine()) != null) {
+                stringBuilder.append(receiveString);
+            }
+            inputStream.close();
+            ret = stringBuilder.toString();
+        }
+
+        try {
+            JSONObject json = new JSONObject(ret);
+            Modules mod = new Modules(json.getString("username"));
+            JSONArray arr = json.getJSONArray("modules");
+            for (JSONObject jsonObject: jsonArrayToIterableObject(arr)) {
+                mod.list.add(new Module(jsonObject));
+            }
+            FileInputStream ofi = context.openFileInput(FILE_NAME_TIMESTAMP);
+            ObjectInputStream inputStream1 = new ObjectInputStream(ofi);
+            mod.mLoadTime = inputStream1.readLong();
+            return mod;
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    public void save(Context context) throws IOException {
+        JSONObject json = new JSONObject();
+        try {
+            json.put("username", mUsername);
+            json.put("modules", UtilsJson.collectionToJson(list));
+            OutputStreamWriter osw = new OutputStreamWriter(context.openFileOutput(FILE_NAME, Context.MODE_PRIVATE));
+            osw.write(json.toString());
+            osw.close();
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+
+        mLoadTime = System.currentTimeMillis();
+        FileOutputStream ofo = context.openFileOutput(FILE_NAME_TIMESTAMP, Context.MODE_PRIVATE);
+        ObjectOutputStream outputStream = new ObjectOutputStream(ofo);
+        outputStream.writeLong(mLoadTime);
+    }
+
+    public void delete(Context context) {
+        context.deleteFile(FILE_NAME);
+    }
+
+    public String getUsername() {
+        return mUsername;
+    }
+
+    public boolean updateList(Modules modules) {
+        SortedListModule old = this.list;
+        this.list = modules.list;
+        boolean isChanged = false;
+        for (Module oldModule : old) {
+            Module newModule = this.list.getById(oldModule.getID());
+            if (newModule != null) {
+                if (!isChanged && !hashEquals(oldModule, newModule))
+                    isChanged = true;
+                newModule.announcements = oldModule.announcements;
+                newModule.assignments = oldModule.assignments;
+                newModule.events = oldModule.events;
+                newModule.gradebook = oldModule.gradebook;
+                newModule.resources = oldModule.resources;
+            } else {
+                isChanged = true;
+            }
+        }
+        return isChanged;
+    }
+
+    private boolean hashEquals(Module o1, Module o2) {
+        if (o1 == null && o2 == null)
+            return true;
+        else if (o1 == null || o2 == null)
+            return false;
+        else
+            return o1.hashCode() == o2.hashCode();
+    }
+
+    public static class Module implements UtilsJson.JsonConvertible {
+        @Nullable public final Semester semester;
+        @NotNull final HashSet<String> lvNumber;
+        @NotNull public final String title;
+        @NotNull public final ArrayList<Lecturer> lecturer;
+        @Nullable public final String type;
+        @Nullable public final String description;
+        @NotNull private final String ID;
+        @Nullable public ArrayList<Announcement> announcements;
+        @Nullable public AssignmentList assignments;
+        @Nullable public EventList events;
+        @Nullable public ArrayList<Grade> gradebook;
+        @Nullable public ArrayList<Resource> resources;
+
+        @Override
+        public int hashCode() {
+            return Objects.hashCode(semester, lvNumber, title, lecturer, type, description, ID);
+        }
+
+        @Override
+        public JSONObject toJSONObject() throws JSONException {
+            JSONObject json = new JSONObject();
+            json.put("semester", semester != null ? semester.toJSONObject() : null);
+            json.put("lvNumber", collectionToJson(lvNumber));
+            json.put("title", title);
+            json.put("lecturer", collectionToJson(lecturer));
+            json.put("type", type);
+            json.put("description", description);
+            json.put("ID", ID);
+            json.put("announcements", collectionToJson(announcements));
+            json.put("assignments", collectionToJson(assignments));
+            json.put("events", collectionToJson(events));
+            json.put("gradebook", collectionToJson(gradebook));
+            json.put("resources", collectionToJson(resources));
+            return json;
+        }
+
+        public float getGradebookPercent(){
+            float maxPoint = 0;
+            float userPoint = 0;
+            if (gradebook != null) {
+                for (Grade g : gradebook){
+                    maxPoint += g.getMaxPoints();
+                    userPoint += g.getPoints();
+                }
+            }
+            if (maxPoint == 0)
+                return 0;
+            return userPoint/maxPoint;
+        }
+
+        private Module(@Nullable Semester semester, @NotNull HashSet<String> lvNumber, @NotNull String title, @NotNull LinkedHashSet<Lecturer> lecturer, @Nullable String type, @Nullable String description, @NotNull String ID) {
+
+            title = title.replaceAll("(.*?) (S[0-9]{2}|W[0-9/]{5})", "$1");
+
+            this.semester = semester;
+            this.lvNumber = lvNumber;
+            this.title = title;
+            this.lecturer = new ArrayList<>(lecturer);
+            this.type = type;
+            this.description = description;
+            this.ID = ID;
+        }
+
+        private Module(@NotNull JSONObject json) throws JSONException {
+            HashSet<String> lv = new HashSet<>();
+            for (String number: UtilsJson.jsonArrayToIterableString(json.getJSONArray("lvNumber"))) {
+                lv.add(number);
+            }
+            LinkedHashSet<Lecturer> lecturer = new LinkedHashSet<>();
+            for (JSONObject l: UtilsJson.jsonArrayToIterableObject(json.getJSONArray("lecturer"))) {
+                lecturer.add(new Lecturer(l));
+            }
+            JSONObject obj = json.optJSONObject("semester");
+
+            this.semester = obj != null ? new Semester(obj) : null;
+            this.lvNumber = lv;
+            this.title = json.getString("title");
+            this.lecturer = new ArrayList<>(lecturer);
+            this.type = json.getString("type");
+            this.description = json.getString("description");
+            this.ID = json.getString("ID");
+
+            JSONArray arr = json.optJSONArray("announcements");
+            if (obj != null) {
+                ArrayList<Announcement> announce = new ArrayList<>();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    announce.add(new Announcement(l));
+                }
+                this.announcements = announce;
+            }
+            arr = json.optJSONArray("assignments");
+            if (obj != null) {
+                AssignmentList assign = new AssignmentList();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    assign.add(new Assignment(l));
+                }
+                this.assignments = assign;
+            }
+
+            arr = json.optJSONArray("events");
+            if (obj != null) {
+                EventList events = new EventList();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    events.add(new Event(l));
+                }
+                this.events = events;
+            }
+            arr = json.optJSONArray("gradebook");
+            if (obj != null) {
+                ArrayList<Grade> grades = new ArrayList<>();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    grades.add(new Grade(l));
+                }
+                this.gradebook = grades;
+            }
+            arr = json.optJSONArray("resources");
+            if (obj != null) {
+                ArrayList<Resource> res = new ArrayList<>();
+                for (JSONObject l: UtilsJson.jsonArrayToIterableObject(arr)) {
+                    if (l.getString("restype").equals("file"))
+                        res.add(new Resource.File(l));
+                    else
+                        res.add(new Resource.Folder(l));
+                }
+                this.resources = res;
+            }
+        }
+
+        @NonNull
+        public String getID() {
+            return ID;
+        }
+
+        @NonNull
+        @Override
+        public String toString() {
+            return "Semester: "+semester+
+                    "\nlvNumber: "+lvNumber.toString()+
+                    "\ntitle: "+title+
+                    "\nlecturer: "+lecturer.toString()+
+                    "\ntype: "+type+
+                    "\nID: "+ID;
+        }
+    }
+}

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Resource.java

@@ -1,17 +1,21 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
 import com.google.android.gms.common.internal.Objects;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.util.ArrayList;
 
 import androidx.annotation.LayoutRes;
+import androidx.annotation.NonNull;
 import de.sebse.fuplanner.R;
+import de.sebse.fuplanner.tools.UtilsJson;
 import de.sebse.fuplanner.tools.ui.treeview.LayoutItemType;
 import de.sebse.fuplanner.tools.ui.treeview.TreeNode;
 
 
-public abstract class Resource implements Serializable {
+public abstract class Resource implements UtilsJson.JsonConvertible {
 
     final String author;
     final long modifiedDate;
@@ -61,6 +65,19 @@ public abstract class Resource implements Serializable {
         return Objects.hashCode(getAuthor(), getContainer(), getModifiedDate(), getTitle(), getUrl());
     }
 
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("author", author);
+        json.put("modifiedDate", modifiedDate);
+        json.put("title", title);
+        json.put("url", url);
+        json.put("visible", visible);
+        json.put("container", container);
+        json.put("restype", "");
+        return json;
+    }
+
     public static class File extends Resource implements LayoutItemType {
         private final String type;
 
@@ -69,6 +86,7 @@ public abstract class Resource implements Serializable {
             this.type = type;
         }
 
+        @NonNull
         @Override
         public String toString() {
             return "Resource{" +
@@ -89,6 +107,14 @@ public abstract class Resource implements Serializable {
         public @LayoutRes int getLayoutId() {
             return R.layout.item_file;
         }
+
+        @Override
+        public JSONObject toJSONObject() throws JSONException {
+            JSONObject json = super.toJSONObject();
+            json.put("type", type);
+            json.put("restype", "file");
+            return json;
+        }
     }
 
     public static class Folder extends Resource implements LayoutItemType {
@@ -111,6 +137,7 @@ public abstract class Resource implements Serializable {
             return children.size();
         }
 
+        @NonNull
         @Override
         public String toString() {
             return "Resource{" +
@@ -135,6 +162,14 @@ public abstract class Resource implements Serializable {
         public @LayoutRes int getLayoutId() {
             return R.layout.item_dir;
         }
+
+        @Override
+        public JSONObject toJSONObject() throws JSONException {
+            JSONObject json = super.toJSONObject();
+            json.put("children", UtilsJson.collectionToJson(children));
+            json.put("restype", "dir");
+            return json;
+        }
     }
 }
 

app/src/main/java/de/sebse/fuplanner/services/kvv/types/Semester.java

@@ -1,11 +1,13 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
 
-import java.io.Serializable;
+import org.json.JSONException;
+import org.json.JSONObject;
 
 import androidx.annotation.Nullable;
 import de.sebse.fuplanner.tools.Regex;
+import de.sebse.fuplanner.tools.UtilsJson;
 
-public class Semester implements Serializable {
+public class Semester implements UtilsJson.JsonConvertible {
     public static final int SEM_WS = 1;
     public static final int SEM_SS = 2;
     private int type;
@@ -17,25 +19,17 @@ public class Semester implements Serializable {
     }
 
     public Semester(String semester_string) throws NoSuchFieldException {
-        /*Semester sem = null;
-            if (semester != null) {
-                sem = new Semester(semester)
-                semester = semester.replace("SS", "S");
-                semester = semester.replaceAll("[0-9]{2}([0-9]{2})", "$1");
-            }*/
-
-
-        /*String s1type = Regex.regex("^(S|WS) ", a);
-        int s1year = Integer.parseInt(Regex.regex("^(S|WS) ([0-9]{2})", a, 2));
-        String s2type = Regex.regex("^(S|WS) ", b);
-        int s2year = Integer.parseInt(Regex.regex("^(S|WS) ([0-9]{2})", b, 2));*/
-
         String type = Regex.regex("^(SS|WS) ", semester_string);
         String year = Regex.regex("^(SS|WS) ([0-9]{2})", semester_string, 2);
         this.type = type.equals("SS") ? SEM_SS : SEM_WS;
         this.year = Integer.parseInt(year);
     }
 
+    public Semester(JSONObject json) throws JSONException {
+        this.type = json.getInt("type");
+        this.year = json.getInt("year");
+    }
+
     public int getType() {
         return type;
     }
@@ -52,4 +46,12 @@ public class Semester implements Serializable {
         }
         return false;
     }
+
+    @Override
+    public JSONObject toJSONObject() throws JSONException {
+        JSONObject json = new JSONObject();
+        json.put("type", type);
+        json.put("year", year);
+        return json;
+    }
 }

app/src/main/java/de/sebse/fuplanner/services/kvv/types/SortedListModule.java

@@ -1,4 +1,7 @@
-package de.sebse.fuplanner.services.KVV.types;
+package de.sebse.fuplanner.services.kvv.types;
+
+import org.json.JSONException;
+import org.json.JSONObject;
 
 import androidx.annotation.Nullable;
 import de.sebse.fuplanner.tools.SortedList;

app/src/main/java/de/sebse/fuplanner/services/kvv/ui/Download.java

@@ -1,4 +1,4 @@
-package de.sebse.fuplanner.services.KVV.ui;
+package de.sebse.fuplanner.services.kvv.ui;
 
 import android.Manifest;
 import android.app.AlertDialog;
@@ -18,7 +18,7 @@ import androidx.core.app.ActivityCompat;
 import androidx.core.content.FileProvider;
 import de.sebse.fuplanner.MainActivity;
 import de.sebse.fuplanner.R;
-import de.sebse.fuplanner.services.KVV.types.Resource;
+import de.sebse.fuplanner.services.kvv.types.Resource;
 import de.sebse.fuplanner.tools.Regex;
 import de.sebse.fuplanner.tools.RequestPermissionsResultListener;
 import de.sebse.fuplanner.tools.UtilsDate;
@@ -31,7 +31,7 @@ public class Download {
     private final ContextInterface contextInterface;
     private final ActivityInterface activityInterface;
     private RequestedDownload requestedDownload;
-    private Logger log = new Logger(this);
+    private final Logger log = new Logger(this);
 
 
     public Download(ContextInterface contextInterface, ActivityInterface activityInterface) {
@@ -106,7 +106,7 @@ public class Download {
         }
         activity.getKVV().modules().resources().file(file.getTitle(), file.getUrl(), folderName, success -> {
             Context context = contextInterface.get();
-            if (success.equals("")) {
+            if (success.equals("") || context== null) {
                 showDownloadError();
             } else {
                 if (Regex.has("^http", success)){
@@ -116,7 +116,6 @@ public class Download {
                 else {
                     fileOpen(new File(success));
                 }
-
             }
         }, log::e, downloadNew);
     }
@@ -140,7 +139,7 @@ public class Download {
     public RequestPermissionsResultListener getRequestPermissionsResultListener() {
         return (requestCode, permissions, grantResults) -> {
             if (requestedDownload == null) {
-                log.d("No request");
+                log.e("No request");
                 return;
             }
             if (activityInterface.get() == null) {
@@ -152,13 +151,11 @@ public class Download {
             {
                 intList.add(i);
             }
-            log.d(requestCode, Arrays.asList(permissions), intList);
             int pos = Arrays.asList(permissions).indexOf("android.permission.WRITE_EXTERNAL_STORAGE");
             if (pos != -1) {
                 if (grantResults[pos] != -1) {
                     downloadOrOpen(requestedDownload.file, requestedDownload.folderName, requestedDownload.downloadNew);
                 } else {
-                    log.d(requestedDownload, pos, grantResults[pos]);
                     showDownloadError();
                 }
                 requestedDownload = null;
@@ -167,9 +164,9 @@ public class Download {
     }
 
     private class RequestedDownload {
-        Resource.File file;
-        String folderName;
-        boolean downloadNew;
+        final Resource.File file;
+        final String folderName;
+        final boolean downloadNew;
 
         RequestedDownload(Resource.File file, String folderName, boolean downloadNew) {
             this.file = file;
@@ -189,7 +186,10 @@ public class Download {
     }
 
     private void fileOpen(File url){
-        Uri uri = FileProvider.getUriForFile(contextInterface.get(), contextInterface.get().getApplicationContext().getPackageName() + ".my.provider", url);
+        Context context = contextInterface.get();
+        if (context == null)
+            return;
+        Uri uri = FileProvider.getUriForFile(context, context.getApplicationContext().getPackageName() + ".my.provider", url);
 
         Intent intent;
         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
@@ -244,7 +244,7 @@ public class Download {
             intent.setDataAndType(uri, "*/*");
         }
         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-        contextInterface.get().startActivity(intent);
+        context.startActivity(intent);
 
     }
 

app/src/main/java/de/sebse/fuplanner/services/news/NewsManager.java

@@ -0,0 +1,91 @@
+package de.sebse.fuplanner.services.news;
+
+import android.content.Context;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Locale;
+
+import de.sebse.fuplanner.R;
+import de.sebse.fuplanner.tools.UtilsDate;
+import de.sebse.fuplanner.tools.network.NetworkCallback;
+import de.sebse.fuplanner.tools.network.NetworkError;
+import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
+import de.sebse.fuplanner.tools.types.NewsList;
+
+public class NewsManager {
+    private NewsList mNewsList;
+    private Context mContext;
+
+    public NewsManager(Context context) {
+        this.mContext = context;
+    }
+
+    public void recv(final NetworkCallback<NewsList> callback, final NetworkErrorCallback errorCallback) {
+        recv(callback, errorCallback, false);
+    }
+
+    public void recv(final NetworkCallback<NewsList> callback, final NetworkErrorCallback errorCallback, final boolean forceRefresh) {
+        if (!forceRefresh && mNewsList != null) {
+            callback.onResponse(mNewsList);
+            return;
+        }
+        String fromAsset = loadJSONFromAsset();
+        if (fromAsset == null)
+            return;
+        String language = Locale.getDefault().getLanguage();
+        JSONArray news;
+        NewsList dates = new NewsList();
+        try {
+            JSONObject json = new JSONObject(fromAsset);
+            news = json.getJSONArray("news");
+        } catch (JSONException e) {
+            e.printStackTrace();
+            errorCallback.onError(new NetworkError(300100, 500, "Parsing news list failed!"));
+            return;
+        }
+
+        for (int i = news.length() - 1; i >= 0; i--) {
+            try {
+                String title = news.getJSONObject(i).optString("title_" + language, null);
+                if (title == null)
+                    title = news.getJSONObject(i).getString("title");
+                String categoryString = news.getJSONObject(i).getString("category");
+                int category;
+                if (categoryString.equals("CATEGORY_TRICKS"))
+                    category = de.sebse.fuplanner.tools.types.News.CATEGORY_TRICKS;
+                else
+                    category = de.sebse.fuplanner.tools.types.News.CATEGORY_UPDATE;
+                String dateString = news.getJSONObject(i).getString("date");
+                long date = UtilsDate.stringToMillis(dateString, "dd.MM.yyyy");
+                String text = news.getJSONObject(i).optString("text_" + language, null);
+                if (text == null)
+                    text = news.getJSONObject(i).getString("text");
+                de.sebse.fuplanner.tools.types.News event = new de.sebse.fuplanner.tools.types.News(title, category, date, text);
+                dates.add(event);
+            } catch (JSONException e) {
+                e.printStackTrace();
+            }
+        }
+        mNewsList = dates;
+        callback.onResponse(mNewsList);
+    }
+
+    private String loadJSONFromAsset() {
+        try {
+            InputStream is = mContext.getResources().openRawResource(R.raw.news);
+            int size = is.available();
+            byte[] buffer = new byte[size];
+            is.read(buffer);
+            is.close();
+            return new String(buffer, "UTF-8");
+        } catch (IOException ex) {
+            ex.printStackTrace();
+            return null;
+        }
+    }
+}

app/src/main/java/de/sebse/fuplanner/tools/CustomAccountManager.java

@@ -0,0 +1,134 @@
+package de.sebse.fuplanner.tools;
+
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.accounts.AccountManagerCallback;
+import android.accounts.AuthenticatorException;
+import android.accounts.OperationCanceledException;
+import android.app.Activity;
+import android.os.Build;
+import android.os.Bundle;
+
+import java.io.IOException;
+
+import androidx.annotation.Nullable;
+import de.sebse.fuplanner.services.kvv.Login;
+import de.sebse.fuplanner.tools.logging.Logger;
+
+public class CustomAccountManager {
+    private final AccountManager mAccountManager;
+    private final ActivityInterface mActivityInterface;
+    private Logger log = new Logger(this);
+
+    public CustomAccountManager(AccountManager manager, ActivityInterface activityInterface) {
+        mAccountManager = manager;
+        this.mActivityInterface = activityInterface;
+    }
+
+
+
+
+
+    public void doInvalidateTokenSync(String accountType, String authTokenType) {
+        Account account = mAccountManager.getAccountsByType(accountType)[0];
+        try {
+            String token = mAccountManager.blockingGetAuthToken(account, authTokenType, true);
+            mAccountManager.invalidateAuthToken(accountType, token);
+        } catch (AuthenticatorException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        } catch (OperationCanceledException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void doInvalidateToken(String accountType, String authTokenType, Login.BooleanInterface callback) {
+        Account account = mAccountManager.getAccountsByType(accountType)[0];
+        mAccountManager.getAuthToken(account, authTokenType, null, true, accountManagerFuture -> {
+            try {
+                Bundle bnd = accountManagerFuture.getResult();
+                String token = bnd.getString(AccountManager.KEY_AUTHTOKEN);
+                mAccountManager.invalidateAuthToken(accountType, token);
+                if (callback != null)
+                    callback.run(true);
+                return;
+            } catch (AuthenticatorException e) {
+                e.printStackTrace();
+            } catch (IOException e) {
+                e.printStackTrace();
+            } catch (OperationCanceledException e) {
+                e.printStackTrace();
+            }
+            if (callback != null)
+                callback.run(false);
+        }, null);
+    }
+
+    public void deleteAccount(String accountType) {
+        Account[] accounts = mAccountManager.getAccountsByType(accountType);
+        int[] count = {accounts.length};
+        for (Account account: accounts) {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1) {
+                mAccountManager.removeAccount(account, null, null, null);
+            } else {
+                mAccountManager.removeAccount(account, null, null);
+            }
+        }
+    }
+
+    public void getTokenByType(String accountType, String authTokenType, @Nullable StringInterface callback) {
+        Activity activity = mActivityInterface.get();
+        AccountManagerCallback<Bundle> cb = (accountManagerFuture -> {
+            try {
+                Bundle bnd = accountManagerFuture.getResult();
+                final String authtoken = bnd.getString(AccountManager.KEY_AUTHTOKEN);
+                if (callback != null)
+                    callback.run(authtoken);
+                return;
+            } catch (AuthenticatorException e) {
+                e.printStackTrace();
+            } catch (IOException e) {
+                e.printStackTrace();
+            } catch (OperationCanceledException e) {
+                e.printStackTrace();
+            }
+            if (callback != null)
+                callback.run(null);
+        });
+        if (activity != null) {
+            mAccountManager.getAuthTokenByFeatures(accountType, authTokenType, null, mActivityInterface.get(), null, null, cb, null);
+        } else {
+            Account account = mAccountManager.getAccountsByType(accountType)[0];
+            mAccountManager.getAuthToken(account, authTokenType, null, true, cb, null);
+        }
+    }
+
+    public String getTokenByTypeSync(String accountType, String authTokenType) {
+        Account account = mAccountManager.getAccountsByType(accountType)[0];
+        try {
+            return  mAccountManager.blockingGetAuthToken(account, authTokenType, true);
+        } catch (AuthenticatorException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        } catch (OperationCanceledException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    public boolean hasAccounts(String accountType) {
+        return mAccountManager.getAccountsByType(accountType).length != 0;
+    }
+
+    @FunctionalInterface
+    public interface ActivityInterface {
+        @Nullable
+        Activity get();
+    }
+
+    public interface StringInterface {
+        void run(@Nullable String string);
+    }
+}

app/src/main/java/de/sebse/fuplanner/tools/DateSortedList.java

@@ -7,6 +7,7 @@ import java.util.Iterator;
 
 public abstract class DateSortedList<T> extends ArrayList<T> {
     private int split = -1;
+    private boolean mSorting = false;
 
     public T getPast(int index) {
         if (split < 0)
@@ -30,6 +31,7 @@ public abstract class DateSortedList<T> extends ArrayList<T> {
 
     @Override
     public T get(int index) {
+        if (mSorting) return super.get(index);
         if (split < 0)
             sort();
         if (reversed())
@@ -55,6 +57,7 @@ public abstract class DateSortedList<T> extends ArrayList<T> {
     }
 
     public void sort() {
+        mSorting = true;
         Collections.sort(this, ((e1, e2) -> Long.compare(getDateByItem(e1), getDateByItem(e2))));
         long now = System.currentTimeMillis();
         split = 0;
@@ -64,6 +67,7 @@ public abstract class DateSortedList<T> extends ArrayList<T> {
             else
                 break;
         }
+        mSorting = false;
     }
 
     public Iterator<T> getEventsOfMonth(int year, int month) {

app/src/main/java/de/sebse/fuplanner/tools/EventListener.java

@@ -3,7 +3,7 @@ package de.sebse.fuplanner.tools;
 import java.util.HashMap;
 
 public class EventListener<T> {
-    private HashMap<String, EventFunction<T>> list = new HashMap<>();
+    private final HashMap<String, EventFunction<T>> list = new HashMap<>();
 
     public void add(String id,EventFunction<T> listener) {
         list.put(id, listener);

app/src/main/java/de/sebse/fuplanner/tools/MainActivityListener.java

@@ -2,9 +2,9 @@ package de.sebse.fuplanner.tools;
 
 import androidx.annotation.StringRes;
 
-import de.sebse.fuplanner.services.Canteen.CanteenBrowser;
-import de.sebse.fuplanner.services.GoogleAuth.GoogleAuth;
-import de.sebse.fuplanner.services.KVV.KVV;
+import de.sebse.fuplanner.services.canteen.CanteenBrowser;
+import de.sebse.fuplanner.services.kvv.KVV;
+import de.sebse.fuplanner.services.news.NewsManager;
 
 public interface MainActivityListener {
     void onTitleTextChange(String newTitle);
@@ -17,12 +17,9 @@ public interface MainActivityListener {
 
     KVV getKVV();
 
-    GoogleAuth getGoogleAuth();
-
     CanteenBrowser getCanteenBrowser();
 
-    @Deprecated
-    void onRefreshCompleted(boolean isFailed);
+    NewsManager getNewsManager();
 
     void addRequestPermissionsResultListener(RequestPermissionsResultListener listener, String id);
 

app/src/main/java/de/sebse/fuplanner/tools/NetworkCallbackCollector.java

@@ -0,0 +1,34 @@
+package de.sebse.fuplanner.tools;
+
+import android.util.Pair;
+
+import java.util.HashSet;
+import java.util.Iterator;
+
+import de.sebse.fuplanner.tools.network.NetworkCallback;
+import de.sebse.fuplanner.tools.network.NetworkError;
+import de.sebse.fuplanner.tools.network.NetworkErrorCallback;
+
+public class NetworkCallbackCollector<T> extends HashSet<Pair<NetworkCallback<T>, NetworkErrorCallback>> {
+    public void add(NetworkCallback<T> success, NetworkErrorCallback error) {
+        add(new Pair<>(success, error));
+    }
+
+    public void responseError(NetworkError error) {
+        Iterator<Pair<NetworkCallback<T>, NetworkErrorCallback>> i;
+        for (i = this.iterator(); i.hasNext();) {
+            Pair<NetworkCallback<T>, NetworkErrorCallback> pair = i.next();
+            pair.second.onError(error);
+            i.remove();
+        }
+    }
+
+    public void responseResponse(T success) {
+        Iterator<Pair<NetworkCallback<T>, NetworkErrorCallback>> i;
+        for (i = this.iterator(); i.hasNext();) {
+            Pair<NetworkCallback<T>, NetworkErrorCallback> pair = i.next();
+            pair.first.onResponse(success);
+            i.remove();
+        }
+    }
+}

app/src/main/java/de/sebse/fuplanner/tools/Preferences.java

@@ -2,6 +2,7 @@ package de.sebse.fuplanner.tools;
 
 import android.content.Context;
 import androidx.annotation.ArrayRes;
+import androidx.annotation.StringRes;
 import androidx.preference.PreferenceManager;
 
 public class Preferences {
@@ -9,4 +10,14 @@ public class Preferences {
         String[] strings = context.getResources().getStringArray(key);
         return PreferenceManager.getDefaultSharedPreferences(context).getString(strings[0], strings[1]);
     }
+
+    public static long getLong(Context context, @StringRes int key) {
+        String string = context.getResources().getString(key);
+        return PreferenceManager.getDefaultSharedPreferences(context).getLong(string, 0);
+    }
+
+    public static void setLong(Context context, @StringRes int key, long value) {
+        String string = context.getResources().getString(key);
+        PreferenceManager.getDefaultSharedPreferences(context).edit().putLong(string, value).apply();
+    }
 }

app/src/main/java/de/sebse/fuplanner/tools/SortedList.java

@@ -3,12 +3,11 @@ package de.sebse.fuplanner.tools;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
 
-public abstract class SortedList<T, I, F> implements Iterable<T>, Serializable {
+public abstract class SortedList<T, I, F> implements Iterable<T> {
 
     private final ArrayList<T> internalList = new ArrayList<>();
 
@@ -120,6 +119,7 @@ public abstract class SortedList<T, I, F> implements Iterable<T>, Serializable {
         };
     }
 
+    @NonNull
     @Override
     public String toString() {
         return this.internalList.toString();

app/src/main/java/de/sebse/fuplanner/tools/Triplet.java

@@ -1,14 +0,0 @@
-package de.sebse.fuplanner.tools;
-
-public class Triplet<T, U, V> {
-
-    public final T first;
-    public final U second;
-    public final V third;
-
-    public Triplet(T first, U second, V third) {
-        this.first = first;
-        this.second = second;
-        this.third = third;
-    }
-}

app/src/main/java/de/sebse/fuplanner/tools/UtilsDate.java

@@ -7,6 +7,7 @@ import android.os.Build;
 import androidx.annotation.Nullable;
 import android.text.format.DateFormat;
 
+import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Locale;
@@ -65,4 +66,17 @@ public class UtilsDate {
     public static boolean dateEquals(long a, long b) {
         return a / 86400000 == b / 86400000;
     }
+
+    public static long stringToMillis(String dateString, String format) {
+        try {
+            @SuppressLint("SimpleDateFormat") SimpleDateFormat sdf = new SimpleDateFormat(format);
+            Date date = sdf.parse(dateString);
+
+            return date.getTime();
+
+        } catch (ParseException e) {
+            e.printStackTrace();
+            return 0;
+        }
+    }
 }

app/src/main/java/de/sebse/fuplanner/tools/UtilsJson.java

@@ -0,0 +1,109 @@
+package de.sebse.fuplanner.tools;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Iterator;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+public class UtilsJson {
+    public static JSONArray collectionToJson(@Nullable HashSet<String> coll) {
+        if (coll == null)
+            return null;
+        JSONArray arr = new JSONArray();
+        for (String e: coll) {
+            arr.put(e);
+        }
+        return arr;
+    }
+
+    public static <E extends JsonConvertible> JSONArray collectionToJson(@Nullable Collection<E> coll) throws JSONException {
+        if (coll == null)
+            return null;
+        JSONArray arr = new JSONArray();
+        for (E e: coll) {
+            arr.put(e.toJSONObject());
+        }
+        return arr;
+    }
+
+    public static JSONArray collectionToJson(@Nullable ArrayList<String> coll) throws JSONException {
+        if (coll == null)
+            return null;
+        JSONArray arr = new JSONArray();
+        for (String e: coll) {
+            arr.put(e);
+        }
+        return arr;
+    }
+
+    public static <A extends JsonConvertible> JSONArray collectionToJson(@Nullable SortedList<A, ?, ?> coll) throws JSONException {
+        if (coll == null)
+            return null;
+        JSONArray arr = new JSONArray();
+        for (A e: coll) {
+            arr.put(e.toJSONObject());
+        }
+        return arr;
+    }
+
+    public static <T> Iterator<T> jsonArrayToIterator(JSONArray array, GetInterface<T> func) {
+        return new Iterator<T>() {
+            int size = array == null ? 0 : array.length();
+            int pos = 0;
+            @Override
+            public boolean hasNext() {
+                return pos < size;
+            }
+
+            @Override
+            public T next() {
+                try {
+                    return func.get(array, pos++);
+                } catch (JSONException e) {
+                    e.printStackTrace();
+                    return null;
+                }
+            }
+        };
+    }
+
+    @FunctionalInterface
+    private interface GetInterface<T> {
+        T get(JSONArray array, int index) throws JSONException;
+    }
+
+    public static JsonIterable<JSONObject> jsonArrayToIterableObject(JSONArray array) {
+        return new JsonIterable<>(array, JSONArray::getJSONObject);
+    }
+
+    public static JsonIterable<String> jsonArrayToIterableString(JSONArray array) {
+        return new JsonIterable<>(array, JSONArray::getString);
+    }
+
+    public static class JsonIterable<T> implements Iterable<T> {
+        private JSONArray array;
+        private GetInterface<T> getInterface;
+
+        JsonIterable(JSONArray array, GetInterface<T> getInterface) {
+            this.array = array;
+            this.getInterface = getInterface;
+        }
+        @NonNull
+        @Override
+        public Iterator<T> iterator() {
+            return UtilsJson.jsonArrayToIterator(array, getInterface);
+        }
+    }
+
+    public interface JsonConvertible {
+        JSONObject toJSONObject() throws JSONException;
+    }
+
+}

app/src/main/java/de/sebse/fuplanner/tools/logging/Logger.java

@@ -32,6 +32,11 @@ public class Logger {
         longLog(concat(msg), Log::e);
     }
 
+    public void t(Object... msg) {
+        longLog(concat(msg), Log::e);
+        new Error().printStackTrace();
+    }
+
     private void longLog(String content, LogInterface logInterface) {
         if (content.length() > 4000) {
             logInterface.run(tag, content.substring(0, 4000));

app/src/main/java/de/sebse/fuplanner/tools/network/HTTPService.java

@@ -27,11 +27,11 @@ import de.sebse.fuplanner.tools.logging.Logger;
 public class HTTPService {
     private final RequestQueue requestQueue;
     private final Context mContext;
-    protected Logger log = new Logger(this);
-    private EventListener<VolleyError> errorResponseListener = new EventListener<>();
-    private EventListener<Result> successResponseListener = new EventListener<>();
+    protected final Logger log = new Logger(this);
+    private final EventListener<VolleyError> errorResponseListener = new EventListener<>();
+    private final EventListener<Result> successResponseListener = new EventListener<>();
 
-    protected HTTPService(Context context) {
+    public HTTPService(Context context) {
         this.mContext = context;
         requestQueue = Volley.newRequestQueue(context, new BetterHurlStack(false));
     }

app/src/main/java/de/sebse/fuplanner/tools/network/NetworkError.java

@@ -1,5 +1,7 @@
 package de.sebse.fuplanner.tools.network;
 
+import androidx.annotation.NonNull;
+
 /**
  * Created by sebastian on 24.10.17.
  */
@@ -27,6 +29,7 @@ public class NetworkError {
         return message;
     }
 
+    @NonNull
     public String toString() {
         return String.valueOf(getCode()) + " - " + getHttpStatus() + " - " + getMessage();
     }

app/src/main/java/de/sebse/fuplanner/tools/types/News.java

@@ -0,0 +1,46 @@
+package de.sebse.fuplanner.tools.types;
+
+public class News {
+    public static final int CATEGORY_TRICKS = 0;
+    public static final int CATEGORY_UPDATE = 1;
+
+    private String title;
+    private int category;
+    private long date;
+    private String text;
+
+    public News(String title, int category, long date, String text) {
+        this.title = title;
+        this.category = category;
+        this.date = date;
+        this.text = text;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public int getCategory() {
+        return category;
+    }
+
+    public long getDate() {
+        return date;
+    }
+
+    public String getText() {
+        return text;
+    }
+
+    @Override
+    public String toString() {
+        return "News{" +
+                "title='" + title + '\'' +
+                ", category=" + category +
+                ", date=" + date +
+                ", text='" + text + '\'' +
+                '}';
+    }
+
+
+}

app/src/main/java/de/sebse/fuplanner/tools/types/NewsList.java

@@ -0,0 +1,15 @@
+package de.sebse.fuplanner.tools.types;
+
+import de.sebse.fuplanner.tools.DateSortedList;
+
+public class NewsList extends DateSortedList<News> {
+    @Override
+    protected long getDateByItem(News item) {
+        return item.getDate();
+    }
+
+    @Override
+    protected boolean reversed() {
+        return true;
+    }
+}

app/src/main/java/de/sebse/fuplanner/tools/ui/AnnouncementViewHolder.java

@@ -5,6 +5,7 @@ import android.widget.TextView;
 
 import com.cunoraz.tagview.TagView;
 
+import androidx.annotation.NonNull;
 import de.sebse.fuplanner.R;
 
 public class AnnouncementViewHolder extends ExpandableCardViewHolder {
@@ -25,6 +26,7 @@ public class AnnouncementViewHolder extends ExpandableCardViewHolder {
 
     }
 
+    @NonNull
     @Override
     public String toString() {
         return super.toString() + " '" + mTitle.getText() + "' '" + mSubTitle.getText() + "'";