New feature: only sync in WiFi

* new setting: only sync in WiFi (or when sync is triggered manually)
* new setting: only sync in specific WiFI (by SSID)
* lower default sync interval when account is created to 4 hours (was 1 day)
* version bump to 1.0.6

app/build.gradle

@@ -17,8 +17,8 @@ android {
         minSdkVersion 14
         targetSdkVersion 22
 
-        versionCode 95
+        versionCode 96
-        versionName "1.0.5"
+        versionName "1.0.6"
 
         buildConfigField "long", "buildTime", System.currentTimeMillis() + "L"
     }

app/src/main/AndroidManifest.xml

@@ -12,6 +12,8 @@
           android:installLocation="internalOnly">
 
     <!-- normal permissions -->
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
+    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.GET_ACCOUNTS"/>
     <uses-permission android:name="android.permission.MANAGE_ACCOUNTS"/>

app/src/main/java/at/bitfire/davdroid/AccountSettings.java

@@ -24,6 +24,7 @@ import android.os.Bundle;
 import android.provider.CalendarContract;
 import android.provider.ContactsContract;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.v7.app.NotificationCompat;
 import android.text.TextUtils;
 
@@ -49,10 +50,13 @@ import okhttp3.HttpUrl;
 public class AccountSettings {
     private final static int CURRENT_VERSION = 3;
     private final static String
-        KEY_SETTINGS_VERSION = "version",
+            KEY_SETTINGS_VERSION = "version",
 
-        KEY_USERNAME = "user_name",
+            KEY_USERNAME = "user_name",
-        KEY_AUTH_PREEMPTIVE = "auth_preemptive";
+            KEY_AUTH_PREEMPTIVE = "auth_preemptive",
+
+            KEY_WIFI_ONLY = "wifi_only",            // sync on WiFi only (default: false)
+            KEY_WIFI_ONLY_SSID = "wifi_only_ssid";  // restrict sync to specific WiFi SSID
 
     /** Time range limitation to the past [in days]
         value = null            default value (DEFAULT_TIME_RANGE_PAST_DAYS)
@@ -159,6 +163,26 @@ public class AccountSettings {
         }
     }
 
+    public boolean getSyncWifiOnly() {
+        return accountManager.getUserData(account, KEY_WIFI_ONLY) != null;
+    }
+
+    public void setSyncWiFiOnly(boolean wiFiOnly) {
+        accountManager.setUserData(account, KEY_WIFI_ONLY, wiFiOnly ? "1" : null);
+    }
+
+    @Nullable
+    public String getSyncWifiOnlySSID() {
+        return accountManager.getUserData(account, KEY_WIFI_ONLY_SSID);
+    }
+
+    public void setSyncWifiOnlySSID(String ssid) {
+        accountManager.setUserData(account, KEY_WIFI_ONLY_SSID, ssid);
+    }
+
+
+    // CalDAV settings
+
     public Integer getTimeRangePastDays() {
         String strDays = accountManager.getUserData(account, KEY_TIME_RANGE_PAST_DAYS);
         if (strDays != null) {
@@ -173,8 +197,7 @@ public class AccountSettings {
     }
 
     public boolean getManageCalendarColors() {
-        String manage = accountManager.getUserData(account, KEY_MANAGE_CALENDAR_COLORS);
+        return accountManager.getUserData(account, KEY_MANAGE_CALENDAR_COLORS) == null;
-        return manage == null;
     }
 
     public void setManageCalendarColors(boolean manage) {

app/src/main/java/at/bitfire/davdroid/model/HomeSet.java

@@ -1,29 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model;
-
-import android.content.ContentValues;
-
-import lombok.ToString;
-
-@ToString
-public class HomeSet {
-
-    public long id, serviceID;
-    public String URL;
-
-    public static HomeSet fromDB(ContentValues values) {
-        HomeSet homeSet = new HomeSet();
-        homeSet.id = values.getAsLong(ServiceDB.HomeSets.ID);
-        homeSet.serviceID = values.getAsLong(ServiceDB.HomeSets.SERVICE_ID);
-        homeSet.URL = values.getAsString(ServiceDB.HomeSets.URL);
-        return homeSet;
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/model/Service.java

@@ -1,29 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model;
-
-import android.content.ContentValues;
-
-public class Service {
-
-    public long id;
-    public String accountName, service, principal;
-    public long lastRefresh;
-
-
-    public static Service fromDB(ContentValues values) {
-        Service service = new Service();
-        service.id = values.getAsLong(ServiceDB.Services.ID);
-        service.accountName = values.getAsString(ServiceDB.Services.ACCOUNT_NAME);
-        service.service = values.getAsString(ServiceDB.Services.SERVICE);
-        service.principal = values.getAsString(ServiceDB.Services.PRINCIPAL);
-        return service;
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/CalendarSyncManager.java

@@ -9,12 +9,9 @@
 package at.bitfire.davdroid.syncadapter;
 
 import android.accounts.Account;
-import android.content.ContentValues;
 import android.content.Context;
 import android.content.SyncResult;
 import android.os.Bundle;
-import android.provider.CalendarContract.Calendars;
-import android.text.TextUtils;
 
 import org.apache.commons.codec.Charsets;
 import org.apache.commons.lang3.StringUtils;
@@ -34,12 +31,11 @@ import at.bitfire.dav4android.DavCalendar;
 import at.bitfire.dav4android.DavResource;
 import at.bitfire.dav4android.exception.DavException;
 import at.bitfire.dav4android.exception.HttpException;
-import at.bitfire.dav4android.property.CalendarColor;
 import at.bitfire.dav4android.property.CalendarData;
-import at.bitfire.dav4android.property.DisplayName;
 import at.bitfire.dav4android.property.GetCTag;
 import at.bitfire.dav4android.property.GetContentType;
 import at.bitfire.dav4android.property.GetETag;
+import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.ArrayUtils;
 import at.bitfire.davdroid.Constants;
@@ -63,8 +59,8 @@ public class CalendarSyncManager extends SyncManager {
     protected static final int MAX_MULTIGET = 20;
 
 
-    public CalendarSyncManager(Context context, Account account, Bundle extras, String authority, SyncResult result, LocalCalendar calendar) throws InvalidAccountException {
+    public CalendarSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult result, LocalCalendar calendar) throws InvalidAccountException {
-        super(context, account, extras, authority, result, "calendar/" + calendar.getId());
+        super(context, account, settings, extras, authority, result, "calendar/" + calendar.getId());
         localCollection = calendar;
     }
 

app/src/main/java/at/bitfire/davdroid/syncadapter/CalendarsSyncAdapterService.java

@@ -10,6 +10,7 @@ package at.bitfire.davdroid.syncadapter;
 import android.accounts.Account;
 import android.content.AbstractThreadedSyncAdapter;
 import android.content.ContentProviderClient;
+import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.SyncResult;
@@ -56,11 +57,15 @@ public class CalendarsSyncAdapterService extends SyncAdapterService {
             super.onPerformSync(account, extras, authority, provider, syncResult);
 
             try {
-                updateLocalCalendars(provider, account);
+                AccountSettings settings = new AccountSettings(getContext(), account);
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
+                    return;
+
+                updateLocalCalendars(provider, account, settings);
 
                 for (LocalCalendar calendar : (LocalCalendar[])LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, CalendarContract.Calendars.SYNC_EVENTS + "!=0", null)) {
                     App.log.info("Synchronizing calendar #"  + calendar.getId() + ", URL: " + calendar.getName());
-                    CalendarSyncManager syncManager = new CalendarSyncManager(getContext(), account, extras, authority, syncResult, calendar);
+                    CalendarSyncManager syncManager = new CalendarSyncManager(getContext(), account, settings, extras, authority, syncResult, calendar);
                     syncManager.performSync();
                 }
             } catch (CalendarStorageException e) {
@@ -73,7 +78,7 @@ public class CalendarsSyncAdapterService extends SyncAdapterService {
             App.log.info("Calendar sync complete");
         }
 
-        private void updateLocalCalendars(ContentProviderClient provider, Account account) throws CalendarStorageException, InvalidAccountException {
+        private void updateLocalCalendars(ContentProviderClient provider, Account account, AccountSettings settings) throws CalendarStorageException {
             SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
             try {
                 // enumerate remote and local calendars
@@ -83,7 +88,6 @@ public class CalendarsSyncAdapterService extends SyncAdapterService {
 
                 LocalCalendar[] local = (LocalCalendar[])LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, null, null);
 
-                AccountSettings settings = new AccountSettings(getContext(), account);
                 boolean updateColors = settings.getManageCalendarColors();
 
                 // delete obsolete local calendar

app/src/main/java/at/bitfire/davdroid/syncadapter/ContactsSyncAdapterService.java

@@ -10,6 +10,7 @@ package at.bitfire.davdroid.syncadapter;
 import android.accounts.Account;
 import android.content.AbstractThreadedSyncAdapter;
 import android.content.ContentProviderClient;
+import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.SyncResult;
@@ -23,6 +24,7 @@ import android.support.annotation.Nullable;
 
 import java.util.logging.Level;
 
+import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.InvalidAccountException;
 import at.bitfire.davdroid.model.CollectionInfo;
@@ -50,13 +52,17 @@ public class ContactsSyncAdapterService extends SyncAdapterService {
 
             SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
             try {
+                AccountSettings settings = new AccountSettings(getContext(), account);
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
+                    return;
+
                 SQLiteDatabase db = dbHelper.getReadableDatabase();
                 Long service = getService(db, account);
                 if (service != null) {
                     CollectionInfo remote = remoteAddressBook(db, service);
                     if (remote != null)
                         try {
-                            ContactsSyncManager syncManager = new ContactsSyncManager(getContext(), account, extras, authority, provider, syncResult, remote);
+                            ContactsSyncManager syncManager = new ContactsSyncManager(getContext(), account, settings, extras, authority, provider, syncResult, remote);
                             syncManager.performSync();
                         } catch(InvalidAccountException e) {
                             App.log.log(Level.SEVERE, "Couldn't get account settings", e);
@@ -65,6 +71,8 @@ public class ContactsSyncAdapterService extends SyncAdapterService {
                         App.log.info("No address book collection selected for synchronization");
                 } else
                     App.log.info("No CardDAV service found in DB");
+            } catch (InvalidAccountException e) {
+                App.log.log(Level.SEVERE, "Couldn't get account settings", e);
             } finally {
                 dbHelper.close();
             }

app/src/main/java/at/bitfire/davdroid/syncadapter/ContactsSyncManager.java

@@ -37,6 +37,7 @@ import at.bitfire.dav4android.property.GetCTag;
 import at.bitfire.dav4android.property.GetContentType;
 import at.bitfire.dav4android.property.GetETag;
 import at.bitfire.dav4android.property.SupportedAddressData;
+import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.ArrayUtils;
 import at.bitfire.davdroid.Constants;
@@ -71,8 +72,8 @@ public class ContactsSyncManager extends SyncManager {
     private boolean hasVCard4;
 
 
-    public ContactsSyncManager(Context context, Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult result, CollectionInfo remote) throws InvalidAccountException {
+    public ContactsSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, ContentProviderClient provider, SyncResult result, CollectionInfo remote) throws InvalidAccountException {
-        super(context, account, extras, authority, result, "addressBook");
+        super(context, account, settings, extras, authority, result, "addressBook");
         this.provider = provider;
         this.remote = remote;
     }

app/src/main/java/at/bitfire/davdroid/syncadapter/SyncAdapterService.java

@@ -16,9 +16,19 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SyncResult;
 import android.database.sqlite.SQLiteDatabase;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+import android.net.wifi.WifiInfo;
+import android.net.wifi.WifiManager;
 import android.os.Bundle;
 import android.os.IBinder;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.support.v4.net.ConnectivityManagerCompat;
+import android.text.TextUtils;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.text.WordUtils;
 
 import java.util.logging.Level;
 
@@ -46,11 +56,39 @@ public abstract class SyncAdapterService extends Service {
 
         @Override
         public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
-            App.log.info("Starting " + authority + " sync");
+            App.log.info("Sync for " + authority + " has been initiated");
 
             // required for dav4android (ServiceLoader)
             Thread.currentThread().setContextClassLoader(getContext().getClassLoader());
         }
+
+        protected boolean checkSyncConditions(@NonNull AccountSettings settings) {
+            if (settings.getSyncWifiOnly()) {
+                ConnectivityManager cm = (ConnectivityManager)getContext().getSystemService(CONNECTIVITY_SERVICE);
+                NetworkInfo network = cm.getActiveNetworkInfo();
+                if (network == null) {
+                    App.log.info("No network available, stopping");
+                    return false;
+                }
+                if (network.getType() != ConnectivityManager.TYPE_WIFI || !network.isConnected()) {
+                    App.log.info("Not on connected WiFi, stopping");
+                    return false;
+                }
+
+                String onlySSID = settings.getSyncWifiOnlySSID();
+                if (onlySSID != null) {
+                    onlySSID = "\"" + onlySSID + "\"";
+                    WifiManager wifi = (WifiManager)getContext().getSystemService(WIFI_SERVICE);
+                    WifiInfo info = wifi.getConnectionInfo();
+                    if (info == null || !onlySSID.equals(info.getSSID())) {
+                        App.log.info("Connected to wrong WiFi network (" + info.getSSID() + ", required: " + onlySSID + "), ignoring");
+                        return false;
+                    }
+                }
+            }
+            return true;
+        }
+
     }
 
 }

app/src/main/java/at/bitfire/davdroid/syncadapter/SyncManager.java

@@ -98,16 +98,14 @@ abstract public class SyncManager {
 
 
 
-    public SyncManager(Context context, Account account, Bundle extras, String authority, SyncResult syncResult, String uniqueCollectionId) throws InvalidAccountException {
+    public SyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult syncResult, String uniqueCollectionId) throws InvalidAccountException {
         this.context = context;
         this.account = account;
+        this.settings = settings;
         this.extras = extras;
         this.authority = authority;
         this.syncResult = syncResult;
 
-        // get account settings (for sync interval etc.)
-        settings = new AccountSettings(context, account);
-
         // create HttpClient with given logger
         httpClient = HttpClient.create(context, account);
 

app/src/main/java/at/bitfire/davdroid/syncadapter/TasksSyncAdapterService.java

@@ -10,6 +10,7 @@ package at.bitfire.davdroid.syncadapter;
 import android.accounts.Account;
 import android.content.AbstractThreadedSyncAdapter;
 import android.content.ContentProviderClient;
+import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.SyncResult;
@@ -25,6 +26,7 @@ import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.logging.Level;
 
+import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.InvalidAccountException;
 import at.bitfire.davdroid.model.CollectionInfo;
@@ -59,11 +61,15 @@ public class TasksSyncAdapterService extends SyncAdapterService {
                 if (provider == null)
                     throw new CalendarStorageException("Couldn't access OpenTasks provider");
 
+                AccountSettings settings = new AccountSettings(getContext(), account);
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
+                    return;
+
                 updateLocalTaskLists(provider, account);
 
                 for (LocalTaskList taskList : (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, null, null)) {
                     App.log.info("Synchronizing task list #"  + taskList.getId() + ", URL: " + taskList.getSyncId());
-                    TasksSyncManager syncManager = new TasksSyncManager(getContext(), account, extras, authority, provider, syncResult, taskList);
+                    TasksSyncManager syncManager = new TasksSyncManager(getContext(), account, settings, extras, authority, provider, syncResult, taskList);
                     syncManager.performSync();
                 }
             } catch (CalendarStorageException e) {

app/src/main/java/at/bitfire/davdroid/syncadapter/TasksSyncManager.java

@@ -9,22 +9,17 @@
 package at.bitfire.davdroid.syncadapter;
 
 import android.accounts.Account;
-import android.content.ContentValues;
 import android.content.Context;
 import android.content.SyncResult;
 import android.os.Bundle;
-import android.text.TextUtils;
 
 import org.apache.commons.codec.Charsets;
 import org.apache.commons.lang3.StringUtils;
-import org.dmfs.provider.tasks.TaskContract.TaskLists;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.Charset;
-import java.util.Calendar;
-import java.util.Date;
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
@@ -34,12 +29,11 @@ import at.bitfire.dav4android.DavCalendar;
 import at.bitfire.dav4android.DavResource;
 import at.bitfire.dav4android.exception.DavException;
 import at.bitfire.dav4android.exception.HttpException;
-import at.bitfire.dav4android.property.CalendarColor;
 import at.bitfire.dav4android.property.CalendarData;
-import at.bitfire.dav4android.property.DisplayName;
 import at.bitfire.dav4android.property.GetCTag;
 import at.bitfire.dav4android.property.GetContentType;
 import at.bitfire.dav4android.property.GetETag;
+import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.ArrayUtils;
 import at.bitfire.davdroid.Constants;
@@ -65,8 +59,8 @@ public class TasksSyncManager extends SyncManager {
     final protected TaskProvider provider;
 
 
-    public TasksSyncManager(Context context, Account account, Bundle extras, String authority, TaskProvider provider, SyncResult result, LocalTaskList taskList) throws InvalidAccountException {
+    public TasksSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, TaskProvider provider, SyncResult result, LocalTaskList taskList) throws InvalidAccountException {
-        super(context, account, extras, authority, result, "taskList/" + taskList.getId());
+        super(context, account, settings, extras, authority, result, "taskList/" + taskList.getId());
         this.provider = provider;
         localCollection = taskList;
     }

app/src/main/java/at/bitfire/davdroid/ui/AccountSettingsActivity.java

@@ -11,6 +11,9 @@ package at.bitfire.davdroid.ui;
 import android.accounts.Account;
 import android.content.DialogInterface;
 import android.content.Intent;
+import android.net.wifi.WifiConfiguration;
+import android.net.wifi.WifiInfo;
+import android.net.wifi.WifiManager;
 import android.os.Bundle;
 import android.provider.CalendarContract;
 import android.provider.ContactsContract;
@@ -22,8 +25,12 @@ import android.support.v7.preference.ListPreference;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceFragmentCompat;
 import android.support.v7.preference.SwitchPreferenceCompat;
+import android.text.TextUtils;
 import android.view.MenuItem;
 
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.logging.Level;
 
 import at.bitfire.davdroid.AccountSettings;
@@ -183,6 +190,34 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 prefSyncTasks.setSummary(R.string.settings_sync_summary_not_available);
             }
 
+            final SwitchPreferenceCompat prefWifiOnly = (SwitchPreferenceCompat)findPreference("sync_wifi_only");
+            prefWifiOnly.setChecked(settings.getSyncWifiOnly());
+            prefWifiOnly.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+                @Override
+                public boolean onPreferenceChange(Preference preference, Object wifiOnly) {
+                    settings.setSyncWiFiOnly((Boolean)wifiOnly);
+                    refresh();
+                    return false;
+                }
+            });
+
+            final EditTextPreference prefWifiOnlySSID = (EditTextPreference)findPreference("sync_wifi_only_ssid");
+            final String onlySSID = settings.getSyncWifiOnlySSID();
+            prefWifiOnlySSID.setText(onlySSID);
+            if (onlySSID != null)
+                prefWifiOnlySSID.setSummary(getString(R.string.settings_sync_wifi_only_ssid_on, onlySSID));
+            else
+                prefWifiOnlySSID.setSummary(R.string.settings_sync_wifi_only_ssid_off);
+            prefWifiOnlySSID.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+                @Override
+                public boolean onPreferenceChange(Preference preference, Object newValue) {
+                    String ssid = (String)newValue;
+                    settings.setSyncWifiOnlySSID(!TextUtils.isEmpty(ssid) ? ssid : null);
+                    refresh(); return false;
+                }
+            });
+
+            // category: CalDAV
             final EditTextPreference prefTimeRangePastDays = (EditTextPreference)findPreference("caldav_time_range_past_days");
             Integer pastDays =  settings.getTimeRangePastDays();
             if (pastDays != null) {
@@ -212,7 +247,8 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 @Override
                 public boolean onPreferenceChange(Preference preference, Object newValue) {
                     settings.setManageCalendarColors((Boolean)newValue);
-                    refresh(); return false;
+                    refresh();
+                    return false;
                 }
             });
 

app/src/main/java/at/bitfire/davdroid/ui/setup/AccountDetailsFragment.java

@@ -32,6 +32,7 @@ import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.Constants;
 import at.bitfire.davdroid.DavService;
+import at.bitfire.davdroid.InvalidAccountException;
 import at.bitfire.davdroid.R;
 import at.bitfire.davdroid.model.CollectionInfo;
 import at.bitfire.davdroid.model.ServiceDB.Collections;
@@ -45,6 +46,7 @@ import lombok.Cleanup;
 public class AccountDetailsFragment extends Fragment {
 
     private static final String KEY_CONFIG = "config";
+    private static final int DEFAULT_SYNC_INTERVAL = 4 * 3600;  // 4 hours
 
     public static AccountDetailsFragment newInstance(DavResourceFinder.Configuration config) {
         AccountDetailsFragment frag = new AccountDetailsFragment();
@@ -107,6 +109,8 @@ public class AccountDetailsFragment extends Fragment {
         SQLiteDatabase db = dbHelper.getWritableDatabase();
         db.beginTransactionNonExclusive();
         try {
+            AccountSettings settings = new AccountSettings(getContext(), account);
+
             Intent refreshIntent = new Intent(getActivity(), DavService.class);
             refreshIntent.setAction(DavService.ACTION_REFRESH_COLLECTIONS);
 
@@ -116,7 +120,7 @@ public class AccountDetailsFragment extends Fragment {
                 getActivity().startService(refreshIntent);
 
                 ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 1);
-                ContentResolver.setSyncAutomatically(account, ContactsContract.AUTHORITY, true);
+                settings.setSyncInterval(ContactsContract.AUTHORITY, DEFAULT_SYNC_INTERVAL);
             } else
                 ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 0);
 
@@ -126,12 +130,12 @@ public class AccountDetailsFragment extends Fragment {
                 getActivity().startService(refreshIntent);
 
                 ContentResolver.setIsSyncable(account, CalendarContract.AUTHORITY, 1);
-                ContentResolver.setSyncAutomatically(account, CalendarContract.AUTHORITY, true);
+                settings.setSyncInterval(CalendarContract.AUTHORITY, DEFAULT_SYNC_INTERVAL);
 
                 if (LocalTaskList.tasksProviderAvailable(getContext().getContentResolver())) {
                     // will only do something if OpenTasks is installed and accessible
                     ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 1);
-                    ContentResolver.setSyncAutomatically(account, TaskProvider.ProviderName.OpenTasks.authority, true);
+                    settings.setSyncInterval(TaskProvider.ProviderName.OpenTasks.authority, DEFAULT_SYNC_INTERVAL);
                 } else
                     // If OpenTasks is installed after DAVdroid, DAVdroid won't get task permissions and crash at every task sync
                     // unless we disable task sync here (before OpenTasks is available).
@@ -142,6 +146,8 @@ public class AccountDetailsFragment extends Fragment {
             }
 
             db.setTransactionSuccessful();
+        } catch(InvalidAccountException e) {
+            App.log.log(Level.SEVERE, "Couldn't access account settings", e);
         } finally {
             db.endTransaction();
         }

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

@@ -166,6 +166,13 @@
         <item quantity="other">Events more than %d days in the past will be ignored</item>
     </plurals>
     <string name="settings_sync_time_range_past_message">Events which are more than this number of days in the past will be ignored (may be 0). Leave blank to synchronize all events.</string>
+    <string name="settings_sync_wifi_only">Sync over WiFi only</string>
+    <string name="settings_sync_wifi_only_on">Synchronization is restricted to WiFi connections</string>
+    <string name="settings_sync_wifi_only_off">Connection type is not taken into consideration</string>
+    <string name="settings_sync_wifi_only_ssid">WiFi SSID restriction</string>
+    <string name="settings_sync_wifi_only_ssid_on">Will only synchronize over %s</string>
+    <string name="settings_sync_wifi_only_ssid_off">All WiFi connections may be used</string>
+    <string name="settings_sync_wifi_only_ssid_message">Enter the name of a WiFi network (SSID) to restrict synchronization to this network, or leave blank for all WiFi connections.</string>
     <string name="settings_manage_calendar_colors">Manage calendar colors</string>
     <string name="settings_manage_calendar_colors_on">Calendar colors are managed by DAVdroid</string>
     <string name="settings_manage_calendar_colors_off">Calendar colors are not set by DAVdroid</string>

app/src/main/res/xml/settings_account.xml

@@ -57,6 +57,25 @@
             android:entries="@array/settings_sync_interval_names"
             android:entryValues="@array/settings_sync_interval_seconds" />
 
+        <SwitchPreferenceCompat
+            android:key="sync_wifi_only"
+            android:persistent="false"
+            android:title="@string/settings_sync_wifi_only"
+            android:summaryOn="@string/settings_sync_wifi_only_on"
+            android:summaryOff="@string/settings_sync_wifi_only_off"
+            />
+
+        <EditTextPreference
+            android:key="sync_wifi_only_ssid"
+            android:dependency="sync_wifi_only"
+            android:persistent="false"
+            android:title="@string/settings_sync_wifi_only_ssid"
+            android:dialogMessage="@string/settings_sync_wifi_only_ssid_message"/>
+
+    </PreferenceCategory>
+
+    <PreferenceCategory android:title="CalDAV">
+
         <EditTextPreference
             android:key="caldav_time_range_past_days"
             android:persistent="false"
@@ -71,6 +90,6 @@
             android:summaryOn="@string/settings_manage_calendar_colors_on"
             android:summaryOff="@string/settings_manage_calendar_colors_off"/>
 
-    </PreferenceCategory>
+</PreferenceCategory>
 
 </PreferenceScreen>