Refactor ConfigXml (#135)

Changelog:
- "Use default folder path given in config.xml" (#101)
- "IllegalStateException: Fragment already added" (#108)
- "Enhancement request for per-folder(device) sync conditions" (#110)
- "NPE crash after key and config regeneration" (#141)
- "Adjust the folder icon to show if it's send/receive or both" (#143)
- "CPU percentage is not shown on the status tab" (#144)
- "Always make individual sync conditions UI available" (#145)
- "IntroducedBy deviceID lost on config change through wrapper UI" (#146)
- "Wrapper doesn't use the same syntax as syncthing core's web UI for device addresses" (#147)
- "Syncthing wrapper "emergency" shutdown on native binary crash doesn't work" (#148)

Commits:

* WIP

* WIP

* Get folder list and paused setting when syncthing is not running

Preparation to solve #110

* Fix NPE in DeviceListFragment#DEVICES_COMPARATOR

* Remove blank line

* Add ConfigXml#getDevices and comparator

Make ConfigXml#saveChanges public

* SyncthingService evaluates per folder/device

sync conditions when syncthing is not running via ConfigXml

* Fix typos and add stubs

* Fix build errors

* DEBUG - Always run syncthing binary

* Fix NPE at RunConditionMonitor pointer

* Add setFolderPause, setDevicePause

to ConfigXml

* Improve logging

* Remove test mode

* Better log levels

* Make ConfigXml#updateIfNeeded private

* Remove SyncthingService#mStartupTask

AsyncTask no longer needed

* Update model/Options (fixes #101)

* Fix NPE after config regeneration (fixes #140)

* Refactor key and config generation

Refactor ConfigXml public functions to allow checking if a valid config exists and trigger key and config (re)genration if something is corrupted.

* Fix crash on export/import (fixes #142)

* ApiRequest - Disable verbose log in release builds

* ConfigXml#updateIfNeeded - Disable "startBrowser"

because it applies to desktop environments and cannot start a mobile browser app

* MainActivity - Always show all tabs

* Show folder/device tab contents from config.xml

if syncthing is not running

* Update ConfigXml#getDevices return model

- compression
- introducer

* Device tab - Hide in/out rate if syncthing is not running

 or if the device is paused

* Update device item layout

* MainActivity/Devices - Prevent showing outdated status

after syncthing core transitioned from "active" to "disabled"

* MainActivity/Folders - Prevent showing outdated status

after syncthing core transitioned from "active" to "disabled"

* Add ConfigRouter class

Provides a transparent access to the config if ...
a) Syncthing is running and REST API is available.
b) Syncthing is NOT running and config.xml is accessed.

* Add pref - Cache local device ID

* Allow excluding self in ConfigRouter#getDevices

* Allow excluding self in ConfigRouter#getDevices (2)

* Update Folder model default values

* Update Folder model defaults (2)

- copiers
- hashers

* WIP - ConfigXml - FolderActivity

Remove unused pref inject code
Cache local device ID in pref
Reduce verbose logging in release builds
Extend ConfigXml#getFolders
Extend ConfigXml#getDevices
Fix ConfigXml#setDevicePause

ToDo ConfigXml#getFolderIgnoreList needs to be implemented

* Implemented ConfigXml#getFolderIgnoreList

* Extend ConfigXml#getDevices

- device.addresses

* WIP - DeviceActivity

Make it available when syncthing is not running

* Fix unsuccessful API bumps while syncthing is starting

* Fix space

* Adjust the folder icon to show if it's send/receive or both (fixes #143)

* Fix lint - item_device_list

* Preserve active tab when syncthing core transitions between running and not running

* Add xmlns:android to item_folder_list

* Remove unused reference from item_folder_list

* Add device icon to device tab

* Fix CPU percentage not showing (fixes #144)

* SyncthingService - Polish iterator code

* Fix MainActivity#updateViewPager (fixes #108)

* Add ConfigXml#updateFolder, updateDevice (1)

* Add ConfigRouter#updateFolder, updateDevice

* Add missing "final" to ConfigXml#updateDevice

* WIP - FolderActivity - Update updateFolder via ConfigRouter

ToDo: Implement ConfigRouter here.

* ConfigRouter - Fix missing return

* DeviceActivity - Update device via ConfigRouter

* Always make individual sync conditions UI available (fixes #145)

regardless if syncthing core is running or not.
Remove SyncthingService dependency from SyncConditionsActivity

* Fix incorrect folder type icon shown

when syncthing core is not running

* Add "introducedBy" to folder and device model (fixes #146)

* Add Folder#getDevices to model

* ConfigXml#updateFolder - Writeback devices sharing the folder

Support preserving the "introducedBy" model field of Folder.java (fixes #146)

* Add ConfigXml#updateFolder - Versioning

* Remove SyncthingService dependency from FolderPickerActivity

because it is no longer required.

* Update ToDo remarks

* Add ConfigXml#updateDevice - Addresses

* Fix DeviceActivity#persistableAddresses to be more graceful (fixes #147)

and accept the same address syntax as syncthing core web UI does.

* Add ConfigXml#removeFolder, removeDevice

* Add ConfigXml#addDevice, addFolder

- Add ConfigXml#isDeviceIdValid
- Do not allow adding empty folder labels or empty device names.
- Update model Folder.java so ConfigXml can handle the ignorePerms XML attribute

* Fix Syncthing wrapper "emergency" shutdown on native binary crash (fixes #148)

* Update translation de

* Add ConfigXml#postFolderIgnoreList

* Update APK version to 0.14.54.3 / 4182

* Revert DEBUG - Always run syncthing binary

* Update whatsnew

app/build.gradle

@@ -37,8 +37,8 @@ android {
         applicationId "com.github.catfriend1.syncthingandroid"
         minSdkVersion 16
         targetSdkVersion 26
-        versionCode 4181
+        versionCode 4182
-        versionName "0.14.54.2"
+        versionName "0.14.54.3"
         testApplicationId 'com.github.catfriend1.syncthingandroid.test'
         testInstrumentationRunner 'android.support.test.runner.AndroidJUnitRunner'
         playAccountConfig = playAccountConfigs.defaultAccountConfig

app/src/main/java/com/nutomic/syncthingandroid/activities/DeviceActivity.java

@@ -34,6 +34,7 @@ import com.nutomic.syncthingandroid.service.RestApi;
 import com.nutomic.syncthingandroid.service.SyncthingService;
 import com.nutomic.syncthingandroid.SyncthingApp;
 import com.nutomic.syncthingandroid.util.Compression;
+import com.nutomic.syncthingandroid.util.ConfigRouter;
 import com.nutomic.syncthingandroid.util.TextWatcherAdapter;
 import com.nutomic.syncthingandroid.util.Util;
 
@@ -68,13 +69,15 @@ public class DeviceActivity extends SyncthingActivity
     public static final String EXTRA_IS_CREATE =
             "com.nutomic.syncthingandroid.activities.DeviceActivity.IS_CREATE";
 
-    private static final String TAG = "DeviceSettingsFragment";
+    private static final String TAG = "DeviceActivity";
     private static final String IS_SHOWING_DISCARD_DIALOG = "DISCARD_FOLDER_DIALOG_STATE";
     private static final String IS_SHOWING_COMPRESSION_DIALOG = "COMPRESSION_FOLDER_DIALOG_STATE";
     private static final String IS_SHOWING_DELETE_DIALOG = "DELETE_FOLDER_DIALOG_STATE";
 
     private static final List<String> DYNAMIC_ADDRESS = Collections.singletonList("dynamic");
 
+    private ConfigRouter mConfig;
+
     private Device mDevice;
 
     private View mIdContainer;
@@ -186,6 +189,8 @@ public class DeviceActivity extends SyncthingActivity
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
+        mConfig = new ConfigRouter(DeviceActivity.this);
+
         super.onCreate(savedInstanceState);
         ((SyncthingApp) getApplication()).component().inject(this);
         setContentView(R.layout.fragment_device);
@@ -338,14 +343,9 @@ public class DeviceActivity extends SyncthingActivity
 
     @Override
     public void onServiceStateChange(SyncthingService.State currentState) {
-        if (currentState != ACTIVE) {
-            finish();
-            return;
-        }
-
         if (!mIsCreateMode) {
-            RestApi restApi = getApi();     // restApi != null because of State.ACTIVE
+            RestApi restApi = getApi();
-            List<Device> devices = restApi.getDevices(false);
+            List<Device> devices = mConfig.getDevices(restApi, false);
             String passedId = getIntent().getStringExtra(EXTRA_DEVICE_ID);
             mDevice = null;
             for (Device currentDevice : devices) {
@@ -427,8 +427,16 @@ public class DeviceActivity extends SyncthingActivity
                             .show();
                     return true;
                 }
-                getApi().addDevice(mDevice, error ->
+                if (isEmpty(mDevice.name)) {
-                        Toast.makeText(this, error, Toast.LENGTH_LONG).show());
+                    Toast.makeText(this, R.string.device_name_required, Toast.LENGTH_LONG)
+                            .show();
+                    return true;
+                }
+                mConfig.addDevice(
+                    getApi(),
+                    mDevice,
+                    error -> Toast.makeText(this, error, Toast.LENGTH_LONG).show()
+                );
                 finish();
                 return true;
             case R.id.share_device_id:
@@ -455,7 +463,8 @@ public class DeviceActivity extends SyncthingActivity
         return new android.app.AlertDialog.Builder(this)
                 .setMessage(R.string.remove_device_confirm)
                 .setPositiveButton(android.R.string.yes, (dialogInterface, i) -> {
-                    getApi().removeDevice(mDevice.deviceID);
+                    mConfig.removeDevice(getApi(), mDevice.deviceID);
+                    mDeviceNeedsToUpdate = false;
                     finish();
                 })
                 .setNegativeButton(android.R.string.no, null)
@@ -474,6 +483,9 @@ public class DeviceActivity extends SyncthingActivity
         }
     }
 
+    /**
+     * Used in mIsCreateMode.
+     */
     private void initDevice() {
         mDevice = new Device();
         mDevice.name = getIntent().getStringExtra(EXTRA_DEVICE_NAME);
@@ -482,6 +494,7 @@ public class DeviceActivity extends SyncthingActivity
         mDevice.compression = METADATA.getValue(this);
         mDevice.introducer = false;
         mDevice.paused = false;
+        mDevice.introducedBy = "";
     }
 
     private void prepareEditMode() {
@@ -501,13 +514,14 @@ public class DeviceActivity extends SyncthingActivity
      */
     private void updateDevice() {
         if (mIsCreateMode) {
-            // If we are about to create this folder, we cannot update via restApi.
+            // If we are about to create this device, we cannot update via restApi.
             return;
         }
         if (mDevice == null) {
             Log.e(TAG, "updateDevice: mDevice == null");
             return;
         }
+        // Log.v(TAG, "deviceID=" + mDevice.deviceID + ", introducedBy=" + mDevice.introducedBy);
 
         // Save device specific preferences.
         Log.v(TAG, "updateDevice: mDevice.deviceID = \'" + mDevice.deviceID + "\'");
@@ -518,26 +532,42 @@ public class DeviceActivity extends SyncthingActivity
         );
         editor.apply();
 
-        // Update device via restApi and send the config to REST endpoint.
+        // Update device using RestApi or ConfigXml.
-        RestApi restApi = getApi();
+        mConfig.updateDevice(getApi(), mDevice);
-        if (restApi == null) {
-            Log.e(TAG, "updateDevice: restApi == null");
-            return;
-        }
-        restApi.updateDevice(mDevice);
     }
 
     private List<String> persistableAddresses(CharSequence userInput) {
-        return isEmpty(userInput)
+        if (isEmpty(userInput)) {
-                ? DYNAMIC_ADDRESS
+            return DYNAMIC_ADDRESS;
-                : Arrays.asList(userInput.toString().split(" "));
+        }
+
+        /**
+         * Be fault-tolerant here.
+         * The user can write like this:
+         * tcp4://192.168.1.67:2222, dynamic
+         * tcp4://192.168.1.67:2222; dynamic
+         * tcp4://192.168.1.67:2222,dynamic
+         * tcp4://192.168.1.67:2222;dynamic
+         * tcp4://192.168.1.67:2222 dynamic
+         */
+        String input = userInput.toString();
+        input = input.replace(",", " ");
+        input = input.replace(";", " ");
+        input = input.replaceAll("\\s+", ", ");
+        // Log.v(TAG, "persistableAddresses: Cleaned user input=" + input);
+
+        // Split and return the addresses as String[].
+        return Arrays.asList(input.split(", "));
     }
 
     private String displayableAddresses() {
+        if (mDevice.addresses == null) {
+            return "";
+        }
         List<String> list = DYNAMIC_ADDRESS.equals(mDevice.addresses)
                 ? DYNAMIC_ADDRESS
                 : mDevice.addresses;
-        return TextUtils.join(" ", list);
+        return TextUtils.join(", ", list);
     }
 
     @Override

app/src/main/java/com/nutomic/syncthingandroid/activities/FirstStartActivity.java

@@ -93,6 +93,21 @@ public class FirstStartActivity extends Activity {
         super.onCreate(savedInstanceState);
         ((SyncthingApp) getApplication()).component().inject(this);
 
+        /**
+         * Check if a valid config exists that can be read and parsed.
+         */
+        Boolean configParseable = false;
+        Boolean configExists = Constants.getConfigFile(this).exists();
+        if (configExists) {
+            ConfigXml configParseTest = new ConfigXml(this);
+            try {
+                configParseTest.loadConfig();
+                configParseable = true;
+            } catch (ConfigXml.OpenConfigException e) {
+                Log.d(TAG, "Failed to parse existing config. Will show key generation slide ...");
+            }
+        }
+
         /**
          * Check if prerequisites to run the app are still in place.
          * If anything mandatory is missing, the according welcome slide(s) will be shown.
@@ -100,7 +115,7 @@ public class FirstStartActivity extends Activity {
         Boolean showSlideStoragePermission = !haveStoragePermission();
         Boolean showSlideIgnoreDozePermission = !haveIgnoreDozePermission();
         Boolean showSlideLocationPermission = !haveLocationPermission();
-        Boolean showSlideKeyGeneration = !Constants.getConfigFile(this).exists();
+        Boolean showSlideKeyGeneration = !configExists || !configParseable;
 
         /**
          * If we don't have to show slides for mandatory prerequisites,
@@ -480,8 +495,10 @@ public class FirstStartActivity extends Activity {
                 cancel(true);
                 return null;
             }
+            configXml = new ConfigXml(firstStartActivity);
             try {
-                configXml = new ConfigXml(firstStartActivity);
+                // Create new secure keys and config.
+                configXml.generateConfig();
             } catch (ExecutableNotFoundException e) {
                 publishProgress(firstStartActivity.getString(R.string.executable_not_found, e.getMessage()));
                 cancel(true);

app/src/main/java/com/nutomic/syncthingandroid/activities/FolderActivity.java

@@ -36,6 +36,7 @@ import com.nutomic.syncthingandroid.service.Constants;
 import com.nutomic.syncthingandroid.service.RestApi;
 import com.nutomic.syncthingandroid.service.SyncthingService;
 import com.nutomic.syncthingandroid.SyncthingApp;
+import com.nutomic.syncthingandroid.util.ConfigRouter;
 import com.nutomic.syncthingandroid.util.FileUtils;
 import com.nutomic.syncthingandroid.util.TextWatcherAdapter;
 import com.nutomic.syncthingandroid.util.Util;
@@ -85,6 +86,7 @@ public class FolderActivity extends SyncthingActivity
     private static final String FOLDER_MARKER_NAME = ".stfolder";
     // private static final String IGNORE_FILE_NAME = ".stignore";
 
+    private ConfigRouter mConfig;
     private Folder mFolder;
     // Contains SAF readwrite access URI on API level >= Build.VERSION_CODES.LOLLIPOP (21)
     private Uri mFolderUri = null;
@@ -154,7 +156,7 @@ public class FolderActivity extends SyncthingActivity
                 case R.id.device_toggle:
                     Device device = (Device) view.getTag();
                     if (isChecked) {
-                        mFolder.addDevice(device.deviceID);
+                        mFolder.addDevice(device);
                     } else {
                         mFolder.removeDevice(device.deviceID);
                     }
@@ -166,6 +168,8 @@ public class FolderActivity extends SyncthingActivity
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
+        mConfig = new ConfigRouter(FolderActivity.this);
+
         super.onCreate(savedInstanceState);
         ((SyncthingApp) getApplication()).component().inject(this);
         setContentView(R.layout.fragment_folder);
@@ -384,14 +388,9 @@ public class FolderActivity extends SyncthingActivity
 
     @Override
     public void onServiceStateChange(SyncthingService.State currentState) {
-        if (currentState != ACTIVE) {
-            finish();
-            return;
-        }
-
         if (!mIsCreateMode) {
-            RestApi restApi = getApi();     // restApi != null because of State.ACTIVE
+            RestApi restApi = getApi();
-            List<Folder> folders = restApi.getFolders();
+            List<Folder> folders = mConfig.getFolders(restApi);
             String passedId = getIntent().getStringExtra(EXTRA_FOLDER_ID);
             mFolder = null;
             for (Folder currentFolder : folders) {
@@ -405,11 +404,15 @@ public class FolderActivity extends SyncthingActivity
                 finish();
                 return;
             }
-            restApi.getFolderIgnoreList(mFolder.id, this::onReceiveFolderIgnoreList);
+            mConfig.getFolderIgnoreList(restApi, mFolder, this::onReceiveFolderIgnoreList);
             checkWriteAndUpdateUI();
         }
+
+        // If the extra is set, we should automatically share the current folder with the given device.
         if (getIntent().hasExtra(EXTRA_DEVICE_ID)) {
-            mFolder.addDevice(getIntent().getStringExtra(EXTRA_DEVICE_ID));
+            Device device = new Device();
+            device.deviceID = getIntent().getStringExtra(EXTRA_DEVICE_ID);
+            mFolder.addDevice(device);
             mFolderNeedsToUpdate = true;
         }
 
@@ -471,13 +474,14 @@ public class FolderActivity extends SyncthingActivity
         mCustomSyncConditionsDialog.setEnabled(mCustomSyncConditionsSwitch.isChecked());
 
         // Populate devicesList.
-        List<Device> devicesList = getApi().getDevices(false);
+        RestApi restApi = getApi();
+        List<Device> devicesList = mConfig.getDevices(restApi, false);
         mDevicesContainer.removeAllViews();
         if (devicesList.isEmpty()) {
             addEmptyDeviceListView();
         } else {
-            for (Device n : devicesList) {
+            for (Device device : devicesList) {
-                addDeviceViewAndSetListener(n, getLayoutInflater());
+                addDeviceViewAndSetListener(device, getLayoutInflater());
             }
         }
 
@@ -511,6 +515,11 @@ public class FolderActivity extends SyncthingActivity
                             .show();
                     return true;
                 }
+                if (TextUtils.isEmpty(mFolder.label)) {
+                    Toast.makeText(this, R.string.folder_label_required, Toast.LENGTH_LONG)
+                            .show();
+                    return true;
+                }
                 if (TextUtils.isEmpty(mFolder.path)) {
                     Toast.makeText(this, R.string.folder_path_required, Toast.LENGTH_LONG)
                             .show();
@@ -531,7 +540,7 @@ public class FolderActivity extends SyncthingActivity
                         dfFolder.createDirectory(FOLDER_MARKER_NAME);
                     }
                 }
-                getApi().createFolder(mFolder);
+                mConfig.addFolder(getApi(), mFolder);
                 finish();
                 return true;
             case R.id.remove:
@@ -554,10 +563,7 @@ public class FolderActivity extends SyncthingActivity
         return new AlertDialog.Builder(this)
                 .setMessage(R.string.remove_folder_confirm)
                 .setPositiveButton(android.R.string.yes, (dialogInterface, i) -> {
-                    RestApi restApi = getApi();
+                    mConfig.removeFolder(getApi(), mFolder.id);
-                    if (restApi != null) {
-                        restApi.removeFolder(mFolder.id);
-                    }
                     mFolderNeedsToUpdate = false;
                     finish();
                 })
@@ -731,17 +737,13 @@ public class FolderActivity extends SyncthingActivity
 
         // Update folder via restApi and send the config to REST endpoint.
         RestApi restApi = getApi();
-        if (restApi == null) {
-            Log.e(TAG, "updateFolder: restApi == null");
-            return;
-        }
 
         // Update ignore list.
         String[] ignore = mEditIgnoreListContent.getText().toString().split("\n");
-        restApi.postFolderIgnoreList(mFolder.id, ignore);
+        mConfig.postFolderIgnoreList(restApi, mFolder, ignore);
 
-        // Update model and send the config to REST endpoint.
+        // Update folder using RestApi or ConfigXml.
-        restApi.updateFolder(mFolder);
+        mConfig.updateFolder(restApi, mFolder);
     }
 
     @Override

app/src/main/java/com/nutomic/syncthingandroid/activities/FolderPickerActivity.java

@@ -9,7 +9,6 @@ import android.content.Intent;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
-import android.os.IBinder;
 import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -31,8 +30,6 @@ import com.google.common.collect.Sets;
 import com.nutomic.syncthingandroid.R;
 import com.nutomic.syncthingandroid.SyncthingApp;
 import com.nutomic.syncthingandroid.service.Constants;
-import com.nutomic.syncthingandroid.service.SyncthingService;
-import com.nutomic.syncthingandroid.service.SyncthingServiceBinder;
 import com.nutomic.syncthingandroid.util.Util;
 
 import java.io.File;
@@ -45,7 +42,7 @@ import java.util.Iterator;
  * Activity that allows selecting a directory in the local file system.
  */
 public class FolderPickerActivity extends SyncthingActivity
-        implements AdapterView.OnItemClickListener, SyncthingService.OnServiceStateChangeListener {
+        implements AdapterView.OnItemClickListener {
 
     private static final String EXTRA_INITIAL_DIRECTORY =
             "com.nutomic.syncthingandroid.activities.FolderPickerActivity.INITIAL_DIRECTORY";
@@ -151,22 +148,6 @@ public class FolderPickerActivity extends SyncthingActivity
         mRootsAdapter.addAll(Sets.newTreeSet(roots));
     }
 
-    @Override
-    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
-        super.onServiceConnected(componentName, iBinder);
-        SyncthingServiceBinder syncthingServiceBinder = (SyncthingServiceBinder) iBinder;
-        syncthingServiceBinder.getService().registerOnServiceStateChangeListener(this);
-    }
-
-    @Override
-    protected void onDestroy() {
-        super.onDestroy();
-        SyncthingService syncthingService = getService();
-        if (syncthingService != null) {
-            syncthingService.unregisterOnServiceStateChangeListener(this::onServiceStateChange);
-        }
-    }
-
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         if (mListView.getAdapter() == mRootsAdapter)
@@ -324,14 +305,6 @@ public class FolderPickerActivity extends SyncthingActivity
         }
     }
 
-    @Override
-    public void onServiceStateChange(SyncthingService.State currentState) {
-        if (!isFinishing() && currentState != SyncthingService.State.ACTIVE) {
-            setResult(Activity.RESULT_CANCELED);
-            finish();
-        }
-    }
-
     /**
      * Displays a list of all available roots, or if there is only one root, the
      * contents of that folder.

app/src/main/java/com/nutomic/syncthingandroid/activities/MainActivity.java

@@ -97,6 +97,9 @@ public class MainActivity extends SyncthingActivity
 
     private ActionBarDrawerToggle mDrawerToggle;
     private DrawerLayout          mDrawerLayout;
+
+    private Boolean oneTimeShot = true;
+
     @Inject SharedPreferences mPreferences;
 
     /**
@@ -104,9 +107,10 @@ public class MainActivity extends SyncthingActivity
      */
     @Override
     public void onServiceStateChange(SyncthingService.State currentState) {
-        if (currentState != mSyncthingServiceState) {
+        mSyncthingServiceState = currentState;
-            mSyncthingServiceState = currentState;
+        if (oneTimeShot) {
             updateViewPager();
+            oneTimeShot = false;
         }
 
         switch (currentState) {
@@ -178,15 +182,12 @@ public class MainActivity extends SyncthingActivity
         }
 
         if (savedInstanceState != null) {
-            mViewPager.setCurrentItem(savedInstanceState.getInt("currentTab"));
             if (savedInstanceState.getBoolean(IS_SHOWING_RESTART_DIALOG)){
                 showRestartDialog();
             }
-            if(savedInstanceState.getBoolean(IS_QRCODE_DIALOG_DISPLAYED)) {
+            if (savedInstanceState.getBoolean(IS_QRCODE_DIALOG_DISPLAYED)) {
                 showQrCodeDialog(savedInstanceState.getString(DEVICEID_KEY), savedInstanceState.getParcelable(QRCODE_BITMAP_KEY));
             }
-        } else {
-            updateViewPager();
         }
 
         fm.beginTransaction().replace(R.id.drawer, mDrawerFragment).commit();
@@ -211,31 +212,21 @@ public class MainActivity extends SyncthingActivity
      * Updates the ViewPager to show tabs depending on the service state.
      */
     private void updateViewPager() {
-        Boolean isServiceActive = mSyncthingServiceState == SyncthingService.State.ACTIVE;
+        final int numPages = 3;
-        final int numPages = (isServiceActive ? 3 : 1);
         FragmentStatePagerAdapter mSectionsPagerAdapter =
                 new FragmentStatePagerAdapter(getSupportFragmentManager()) {
 
             @Override
             public Fragment getItem(int position) {
-                if (isServiceActive) {
+                switch (position) {
-                    switch (position) {
+                    case 0:
-                        case 0:
+                        return mFolderListFragment;
-                            return mFolderListFragment;
+                    case 1:
-                        case 1:
+                        return mDeviceListFragment;
-                            return mDeviceListFragment;
+                    case 2:
-                        case 2:
+                        return mStatusFragment;
-                            return mStatusFragment;
+                    default:
-                        default:
+                        return null;
-                            return null;
-                    }
-                } else {
-                    switch (position) {
-                        case 0:
-                            return mStatusFragment;
-                        default:
-                            return null;
-                    }
                 }
             }
 
@@ -251,24 +242,15 @@ public class MainActivity extends SyncthingActivity
 
             @Override
             public CharSequence getPageTitle(int position) {
-                if (isServiceActive) {
+                switch (position) {
-                    switch (position) {
+                    case 0:
-                        case 0:
+                        return getResources().getString(R.string.folders_fragment_title);
-                            return getResources().getString(R.string.folders_fragment_title);
+                    case 1:
-                        case 1:
+                        return getResources().getString(R.string.devices_fragment_title);
-                            return getResources().getString(R.string.devices_fragment_title);
+                    case 2:
-                        case 2:
+                        return getResources().getString(R.string.status_fragment_title);
-                            return getResources().getString(R.string.status_fragment_title);
+                    default:
-                        default:
+                        return String.valueOf(position);
-                            return String.valueOf(position);
-                    }
-                } else {
-                    switch (position) {
-                        case 0:
-                            return getResources().getString(R.string.status_fragment_title);
-                        default:
-                            return String.valueOf(position);
-                        }
                 }
             }
         };
@@ -316,9 +298,9 @@ public class MainActivity extends SyncthingActivity
         SyncthingService mSyncthingService = getService();
         if (mSyncthingService != null) {
             mSyncthingService.unregisterOnServiceStateChangeListener(this);
+            mSyncthingService.unregisterOnServiceStateChangeListener(mDrawerFragment);
             mSyncthingService.unregisterOnServiceStateChangeListener(mFolderListFragment);
             mSyncthingService.unregisterOnServiceStateChangeListener(mDeviceListFragment);
-            mSyncthingService.unregisterOnServiceStateChangeListener(mDrawerFragment);
             mSyncthingService.unregisterOnServiceStateChangeListener(mStatusFragment);
         }
     }
@@ -329,9 +311,9 @@ public class MainActivity extends SyncthingActivity
         SyncthingServiceBinder syncthingServiceBinder = (SyncthingServiceBinder) iBinder;
         SyncthingService syncthingService = syncthingServiceBinder.getService();
         syncthingService.registerOnServiceStateChangeListener(this);
+        syncthingService.registerOnServiceStateChangeListener(mDrawerFragment);
         syncthingService.registerOnServiceStateChangeListener(mFolderListFragment);
         syncthingService.registerOnServiceStateChangeListener(mDeviceListFragment);
-        syncthingService.registerOnServiceStateChangeListener(mDrawerFragment);
         syncthingService.registerOnServiceStateChangeListener(mStatusFragment);
     }
 
@@ -351,11 +333,9 @@ public class MainActivity extends SyncthingActivity
         putFragment.accept(mFolderListFragment);
         putFragment.accept(mDeviceListFragment);
         putFragment.accept(mStatusFragment);
-        putFragment.accept(mDrawerFragment);
 
-        outState.putInt("currentTab", mViewPager.getCurrentItem());
         outState.putBoolean(IS_SHOWING_RESTART_DIALOG, mRestartDialog != null && mRestartDialog.isShowing());
-        if(mQrCodeDialog != null && mQrCodeDialog.isShowing()) {
+        if (mQrCodeDialog != null && mQrCodeDialog.isShowing()) {
             outState.putBoolean(IS_QRCODE_DIALOG_DISPLAYED, true);
             ImageView qrCode = mQrCodeDialog.findViewById(R.id.qrcode_image_view);
             TextView deviceID = mQrCodeDialog.findViewById(R.id.device_id);

app/src/main/java/com/nutomic/syncthingandroid/activities/SyncConditionsActivity.java

@@ -6,7 +6,6 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
-import android.os.IBinder;
 import android.support.v7.widget.SwitchCompat;
 import android.util.Log;
 import android.util.TypedValue;
@@ -23,8 +22,6 @@ import com.google.common.collect.Sets;
 import com.nutomic.syncthingandroid.R;
 import com.nutomic.syncthingandroid.SyncthingApp;
 import com.nutomic.syncthingandroid.service.Constants;
-import com.nutomic.syncthingandroid.service.SyncthingService;
-import com.nutomic.syncthingandroid.service.SyncthingServiceBinder;
 import com.nutomic.syncthingandroid.util.Util;
 
 import java.util.HashSet;
@@ -41,8 +38,7 @@ import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;
 /**
  * Activity that allows selecting a directory in the local file system.
  */
-public class SyncConditionsActivity extends SyncthingActivity
+public class SyncConditionsActivity extends SyncthingActivity {
-        implements SyncthingService.OnServiceStateChangeListener {
 
     private static final String TAG = "SyncConditionsActivity";
 
@@ -215,20 +211,9 @@ public class SyncConditionsActivity extends SyncthingActivity
         }
     };
 
-    @Override
-    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
-        super.onServiceConnected(componentName, iBinder);
-        SyncthingServiceBinder syncthingServiceBinder = (SyncthingServiceBinder) iBinder;
-        syncthingServiceBinder.getService().registerOnServiceStateChangeListener(this);
-    }
-
     @Override
     protected void onDestroy() {
         super.onDestroy();
-        SyncthingService syncthingService = getService();
-        if (syncthingService != null) {
-            syncthingService.unregisterOnServiceStateChangeListener(this::onServiceStateChange);
-        }
     }
 
     @Override
@@ -284,12 +269,4 @@ public class SyncConditionsActivity extends SyncthingActivity
         finish();
     }
 
-    @Override
-    public void onServiceStateChange(SyncthingService.State currentState) {
-        if (!isFinishing() && currentState != SyncthingService.State.ACTIVE) {
-            setResult(Activity.RESULT_CANCELED);
-            finish();
-        }
-    }
-
 }

app/src/main/java/com/nutomic/syncthingandroid/activities/WebGuiActivity.java

@@ -133,9 +133,10 @@ public class WebGuiActivity extends SyncthingActivity
         setContentView(R.layout.activity_web_gui);
 
         mLoadingView = findViewById(R.id.loading);
+        mConfig = new ConfigXml(this);
         try {
-            mConfig = new ConfigXml(this);
+            mConfig.loadConfig();
-        } catch (Exception e) {
+        } catch (ConfigXml.OpenConfigException e) {
             throw new RuntimeException(e.getMessage());
         }
         loadCaCert();

app/src/main/java/com/nutomic/syncthingandroid/fragments/DeviceListFragment.java

@@ -20,6 +20,7 @@ import com.nutomic.syncthingandroid.model.Device;
 import com.nutomic.syncthingandroid.service.Constants;
 import com.nutomic.syncthingandroid.service.RestApi;
 import com.nutomic.syncthingandroid.service.SyncthingService;
+import com.nutomic.syncthingandroid.util.ConfigXml;
 import com.nutomic.syncthingandroid.views.DevicesAdapter;
 
 import java.util.Collections;
@@ -34,7 +35,14 @@ public class DeviceListFragment extends ListFragment implements SyncthingService
 
     private final static String TAG = "DeviceListFragment";
 
-    private final static Comparator<Device> DEVICES_COMPARATOR = (lhs, rhs) -> lhs.name.compareTo(rhs.name);
+    /**
+     * Compares devices by name, uses the device ID as fallback if the name is empty
+     */
+    private final static Comparator<Device> DEVICES_COMPARATOR = (lhs, rhs) -> {
+        String lhsName = lhs.name != null && !lhs.name.isEmpty() ? lhs.name : lhs.deviceID;
+        String rhsName = rhs.name != null && !rhs.name.isEmpty() ? rhs.name : rhs.deviceID;
+        return lhsName.compareTo(rhsName);
+    };
 
     private Runnable mUpdateListRunnable = new Runnable() {
         @Override
@@ -107,9 +115,6 @@ public class DeviceListFragment extends ListFragment implements SyncthingService
      *  while the user is looking at the current tab.
      */
     private void onTimerEvent() {
-        if (mServiceState != SyncthingService.State.ACTIVE) {
-            return;
-        }
         MainActivity mainActivity = (MainActivity) getActivity();
         if (mainActivity == null) {
             return;
@@ -117,10 +122,6 @@ public class DeviceListFragment extends ListFragment implements SyncthingService
         if (mainActivity.isFinishing()) {
             return;
         }
-        RestApi restApi = mainActivity.getApi();
-        if (restApi == null) {
-            return;
-        }
         Log.v(TAG, "Invoking updateList on UI thread");
         mainActivity.runOnUiThread(DeviceListFragment.this::updateList);
     }
@@ -135,11 +136,19 @@ public class DeviceListFragment extends ListFragment implements SyncthingService
         if (activity == null || getView() == null || activity.isFinishing()) {
             return;
         }
+        List<Device> devices;
         RestApi restApi = activity.getApi();
-        if (restApi == null || !restApi.isConfigLoaded()) {
+        if (restApi == null ||
-            return;
+                !restApi.isConfigLoaded() ||
+                mServiceState != SyncthingService.State.ACTIVE) {
+            // Syncthing is not running or REST API is not available yet.
+            ConfigXml configXml = new ConfigXml(activity);
+            configXml.loadConfig();
+            devices = configXml.getDevices(false);
+        } else {
+            // Syncthing is running and REST API is available.
+            devices = restApi.getDevices(false);
         }
-        List<Device> devices = restApi.getDevices(false);
         if (devices == null) {
             return;
         }
@@ -153,7 +162,7 @@ public class DeviceListFragment extends ListFragment implements SyncthingService
         mAdapter.clear();
         Collections.sort(devices, DEVICES_COMPARATOR);
         mAdapter.addAll(devices);
-        mAdapter.updateConnections(restApi);
+        mAdapter.updateDeviceStatus(restApi);
         mAdapter.notifyDataSetChanged();
         setListShown(true);
     }

app/src/main/java/com/nutomic/syncthingandroid/fragments/FolderListFragment.java

@@ -19,6 +19,7 @@ import com.nutomic.syncthingandroid.model.Folder;
 import com.nutomic.syncthingandroid.service.Constants;
 import com.nutomic.syncthingandroid.service.RestApi;
 import com.nutomic.syncthingandroid.service.SyncthingService;
+import com.nutomic.syncthingandroid.util.ConfigXml;
 import com.nutomic.syncthingandroid.views.FoldersAdapter;
 
 import java.util.List;
@@ -102,9 +103,6 @@ public class FolderListFragment extends ListFragment implements SyncthingService
      *  while the user is looking at the current tab.
      */
     private void onTimerEvent() {
-        if (mServiceState != SyncthingService.State.ACTIVE) {
-            return;
-        }
         MainActivity mainActivity = (MainActivity) getActivity();
         if (mainActivity == null) {
             return;
@@ -112,10 +110,6 @@ public class FolderListFragment extends ListFragment implements SyncthingService
         if (mainActivity.isFinishing()) {
             return;
         }
-        RestApi restApi = mainActivity.getApi();
-        if (restApi == null) {
-            return;
-        }
         Log.v(TAG, "Invoking updateList on UI thread");
         mainActivity.runOnUiThread(FolderListFragment.this::updateList);
     }
@@ -130,11 +124,19 @@ public class FolderListFragment extends ListFragment implements SyncthingService
         if (activity == null || getView() == null || activity.isFinishing()) {
             return;
         }
+        List<Folder> folders;
         RestApi restApi = activity.getApi();
-        if (restApi == null || !restApi.isConfigLoaded()) {
+        if (restApi == null ||
-            return;
+                !restApi.isConfigLoaded() ||
+                mServiceState != SyncthingService.State.ACTIVE) {
+            // Syncthing is not running or REST API is not available yet.
+            ConfigXml configXml = new ConfigXml(activity);
+            configXml.loadConfig();
+            folders = configXml.getFolders();
+        } else {
+            // Syncthing is running and REST API is available.
+            folders = restApi.getFolders();
         }
-        List<Folder> folders = restApi.getFolders();
         if (folders == null) {
             return;
         }

app/src/main/java/com/nutomic/syncthingandroid/fragments/StatusFragment.java

@@ -260,7 +260,7 @@ public class StatusFragment extends ListFragment implements SyncthingService.OnS
         int announceConnected =
                 announceTotal - Optional.fromNullable(systemStatus.discoveryErrors).transform(Map::size).or(0);
         synchronized (mStatusHolderLock) {
-            mCpuUsage = (systemStatus.cpuPercent / 100 < 1) ? "" : percentFormat.format(systemStatus.cpuPercent / 100);
+            mCpuUsage = (systemStatus.cpuPercent < 5) ? "" : percentFormat.format(systemStatus.cpuPercent / 100);
             mRamUsage = Util.readableFileSize(mActivity, systemStatus.sys);
             mAnnounceServer = (announceTotal == 0) ?
                     "" :

app/src/main/java/com/nutomic/syncthingandroid/http/ApiRequest.java

@@ -38,6 +38,8 @@ public abstract class ApiRequest {
 
     private static final String TAG = "ApiRequest";
 
+    private static final Boolean ENABLE_VERBOSE_LOG = false;
+
     /**
      * The name of the HTTP header used for the syncthing API key.
      */
@@ -92,7 +94,9 @@ public abstract class ApiRequest {
      */
     void connect(int requestMethod, Uri uri, @Nullable String requestBody,
                  @Nullable OnSuccessListener listener, @Nullable OnErrorListener errorListener) {
-        Log.v(TAG, "Performing request to " + uri.toString());
+        if (ENABLE_VERBOSE_LOG) {
+            Log.v(TAG, "Performing request to " + uri.toString());
+        }
         StringRequest request = new StringRequest(requestMethod, uri.toString(), reply -> {
             if (listener != null) {
                 listener.onSuccess(reply);

app/src/main/java/com/nutomic/syncthingandroid/model/Device.java

@@ -10,17 +10,29 @@ public class Device {
     public List<String> addresses;
     public String compression;
     public String certName;
-    public boolean introducer;
+    public String introducedBy = "";
+    public boolean introducer = false;
     public boolean paused;
     public List<PendingFolder> pendingFolders;
     public List<IgnoredFolder> ignoredFolders;
 
+    /**
+     * Relevant fields for Folder.List<Device> "shared-with-device" model,
+     * handled by {@link ConfigRouter#updateFolder and ConfigXml#updateFolder}
+     *  deviceID
+     *  introducedBy
+     * Example Tag
+     *  <folder ...>
+     *      <device id="[DEVICE_SHARING_THAT_FOLDER_WITH_US]" introducedBy="[INTRODUCER_DEVICE_THAT_TOLD_US_ABOUT_THE_FOLDER_OR_EMPTY_STRING]"></device>
+     *  </folder>
+     */
+
     /**
      * Returns the device name, or the first characters of the ID if the name is empty.
      */
     public String getDisplayName() {
         return (TextUtils.isEmpty(name))
-                ? deviceID.substring(0, 7)
+                ? (TextUtils.isEmpty(deviceID) ? "" : deviceID.substring(0, 7))
                 : name;
     }
 }

app/src/main/java/com/nutomic/syncthingandroid/model/Folder.java

@@ -21,15 +21,15 @@ public class Folder {
     public boolean fsWatcherEnabled = true;
     public int fsWatcherDelayS = 10;
     private List<Device> devices = new ArrayList<>();
-    public int rescanIntervalS;
+    public int rescanIntervalS = 3600;
-    public final boolean ignorePerms = true;
+    public boolean ignorePerms = true;
     public boolean autoNormalize = true;
     public MinDiskFree minDiskFree;
     public Versioning versioning;
-    public int copiers;
+    public int copiers = 0;
     public int pullerMaxPendingKiB;
-    public int hashers;
+    public int hashers = 0;
-    public String order;
+    public String order = "random";
     public boolean ignoreDelete;
     public int scanProgressIntervalS;
     public int pullerPauseS;
@@ -52,12 +52,17 @@ public class Folder {
         public String unit;
     }
 
-    public void addDevice(String deviceId) {
+    public void addDevice(final Device device) {
         Device d = new Device();
-        d.deviceID = deviceId;
+        d.deviceID = device.deviceID;
+        d.introducedBy = device.introducedBy;
         devices.add(d);
     }
 
+    public List<Device> getDevices() {
+        return devices;
+    }
+
     public Device getDevice(String deviceId) {
         for (Device d : devices) {
             if (d.deviceID.equals(deviceId)) {
@@ -78,6 +83,8 @@ public class Folder {
 
     @Override
     public String toString() {
-        return !TextUtils.isEmpty(label) ? label : id;
+        return (TextUtils.isEmpty(label))
+                ? (TextUtils.isEmpty(id) ? "" : id)
+                : label;
     }
 }

app/src/main/java/com/nutomic/syncthingandroid/model/Options.java

@@ -34,6 +34,7 @@ public class Options {
     public String[] alwaysLocalNets;
     public boolean overwriteRemoteDeviceNamesOnConnect;
     public int tempIndexMinBlocks;
+    public String defaultFolderPath;
 
     public static final int USAGE_REPORTING_UNDECIDED = 0;
     public static final int USAGE_REPORTING_DENIED    = -1;

app/src/main/java/com/nutomic/syncthingandroid/service/Constants.java

@@ -68,6 +68,7 @@ public class Constants {
      * Cached information which is not available on SettingsActivity.
      */
     public static final String PREF_LAST_BINARY_VERSION         = "lastBinaryVersion";
+    public static final String PREF_LOCAL_DEVICE_ID             = "localDeviceID";
 
     /**
      * {@link EventProcessor}

app/src/main/java/com/nutomic/syncthingandroid/service/RestApi.java

@@ -71,7 +71,6 @@ public class RestApi {
     private final static Comparator<Folder> FOLDERS_COMPARATOR = (lhs, rhs) -> {
         String lhsLabel = lhs.label != null && !lhs.label.isEmpty() ? lhs.label : lhs.id;
         String rhsLabel = rhs.label != null && !rhs.label.isEmpty() ? rhs.label : rhs.id;
-
         return lhsLabel.compareTo(rhsLabel);
     };
 
@@ -453,7 +452,7 @@ public class RestApi {
     /**
      * This is only used for new folder creation, see {@link FolderActivity}.
      */
-    public void createFolder(Folder folder) {
+    public void addFolder(Folder folder) {
         synchronized (mConfigLock) {
             // Add the new folder to the model.
             mConfig.folders.add(folder);
@@ -500,7 +499,7 @@ public class RestApi {
      *
      * @param includeLocal True if the local device should be included in the result.
      */
-    public List<Device> getDevices(boolean includeLocal) {
+    public List<Device> getDevices(Boolean includeLocal) {
         List<Device> devices;
         synchronized (mConfigLock) {
             devices = deepCopy(mConfig.devices, new TypeToken<List<Device>>(){}.getType());
@@ -850,6 +849,7 @@ public class RestApi {
                         Log.v(TAG, "onSyncPreconditionChanged: syncFolder(" + folder.id + ")=" + (syncConditionsMet ? "1" : "0"));
                         if (folder.paused != !syncConditionsMet) {
                             folder.paused = !syncConditionsMet;
+                            Log.d(TAG, "onSyncPreconditionChanged: syncFolder(" + folder.id + ")=" + (syncConditionsMet ? ">1" : ">0"));
                             configChanged = true;
                         }
                     }
@@ -872,6 +872,7 @@ public class RestApi {
                         Log.v(TAG, "onSyncPreconditionChanged: syncDevice(" + device.deviceID + ")=" + (syncConditionsMet ? "1" : "0"));
                         if (device.paused != !syncConditionsMet) {
                             device.paused = !syncConditionsMet;
+                            Log.d(TAG, "onSyncPreconditionChanged: syncDevice(" + device.deviceID + ")=" + (syncConditionsMet ? ">1" : ">0"));
                             configChanged = true;
                         }
                     }

app/src/main/java/com/nutomic/syncthingandroid/service/RunConditionMonitor.java

@@ -58,7 +58,7 @@ public class RunConditionMonitor {
     }
 
     public interface OnSyncPreconditionChangedListener {
-        void onSyncPreconditionChanged();
+        void onSyncPreconditionChanged(RunConditionMonitor runConditionMonitor);
     }
 
     private class SyncConditionResult {
@@ -189,7 +189,7 @@ public class RunConditionMonitor {
 
         // Notify about changed preconditions.
         if (mOnSyncPreconditionChangedListener != null) {
-            mOnSyncPreconditionChangedListener.onSyncPreconditionChanged();
+            mOnSyncPreconditionChangedListener.onSyncPreconditionChanged(this);
         }
     }
 

app/src/main/java/com/nutomic/syncthingandroid/service/SyncthingRunnable.java

@@ -40,6 +40,8 @@ import javax.inject.Inject;
 
 import eu.chainfire.libsuperuser.Shell;
 
+import static com.nutomic.syncthingandroid.service.SyncthingService.EXTRA_STOP_AFTER_CRASHED_NATIVE;
+
 /**
  * Runs the syncthing binary from command line, and prints its output to logcat.
  *
@@ -258,8 +260,10 @@ public class SyncthingRunnable implements Runnable {
 
         // Notify {@link SyncthingService} that service state State.ACTIVE is no longer valid.
         if (!returnStdOut && sendStopToService) {
-            mContext.startService(new Intent(mContext, SyncthingService.class)
+            Intent intent = new Intent(mContext, SyncthingService.class);
-                    .setAction(SyncthingService.ACTION_STOP));
+            intent.setAction(SyncthingService.ACTION_STOP);
+            intent.putExtra(EXTRA_STOP_AFTER_CRASHED_NATIVE, true);
+            mContext.startService(intent);
         }
 
         // Return captured command line output.

app/src/main/java/com/nutomic/syncthingandroid/service/SyncthingService.java

@@ -8,6 +8,7 @@ import android.Manifest;
 import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Handler;
+import android.os.Looper;
 import android.os.SystemClock;
 import android.support.annotation.Nullable;
 import android.support.v4.content.ContextCompat;
@@ -20,6 +21,7 @@ import com.google.common.io.Files;
 import com.nutomic.syncthingandroid.R;
 import com.nutomic.syncthingandroid.SyncthingApp;
 import com.nutomic.syncthingandroid.http.PollWebGuiAvailableTask;
+import com.nutomic.syncthingandroid.model.Device;
 import com.nutomic.syncthingandroid.model.Folder;
 import com.nutomic.syncthingandroid.util.ConfigXml;
 import com.nutomic.syncthingandroid.util.FileUtils;
@@ -37,6 +39,7 @@ import java.nio.file.Paths;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -112,6 +115,13 @@ public class SyncthingService extends Service {
     public static final String EXTRA_FOLDER_ID =
             "com.nutomic.syncthingandroid.service.SyncthingService.EXTRA_FOLDER_ID";
 
+    /**
+     * Extra used together with ACTION_STOP.
+     */
+    public static final String EXTRA_STOP_AFTER_CRASHED_NATIVE =
+            "com.nutomic.syncthingandroid.service.SyncthingService.EXTRA_STOP_AFTER_CRASHED_NATIVE";
+
+
     public interface OnSyncthingKilled {
         void onKilled();
     }
@@ -155,7 +165,6 @@ public class SyncthingService extends Service {
      */
     private State mCurrentState = State.DISABLED;
     private ConfigXml mConfig;
-    private StartupTask mStartupTask = null;
     private Thread mSyncthingRunnableThread = null;
     private Handler mHandler;
 
@@ -276,9 +285,23 @@ public class SyncthingService extends Service {
 
         if (ACTION_RESTART.equals(intent.getAction()) && mCurrentState == State.ACTIVE) {
             shutdown(State.INIT, () -> launchStartupTask(SyncthingRunnable.Command.main));
-        } else if (ACTION_STOP.equals(intent.getAction()) && mCurrentState == State.ACTIVE) {
+        } else if (ACTION_STOP.equals(intent.getAction())) {
-            shutdown(State.DISABLED, () -> {
+            if (intent.getBooleanExtra(EXTRA_STOP_AFTER_CRASHED_NATIVE, false)) {
-            });
+                /**
+                 * We were requested to stop the service because the syncthing native binary crashed.
+                 * Changing mCurrentState prevents the "defer until syncthing is started" routine we normally
+                 * use for clean shutdown to take place. Instead, we will immediately shutdown the crashed
+                 * instance forcefully.
+                 */
+                mCurrentState = State.ERROR;
+                shutdown(State.DISABLED, () -> {});
+            } else {
+                // Graceful shutdown.
+                if (mCurrentState == State.STARTING ||
+                        mCurrentState == State.ACTIVE) {
+                    shutdown(State.DISABLED, () -> {});
+                }
+            }
         } else if (ACTION_RESET_DATABASE.equals(intent.getAction())) {
             Log.i(TAG, "Invoking reset of database");
             shutdown(State.INIT, () -> {
@@ -348,10 +371,84 @@ public class SyncthingService extends Service {
      * After sync preconditions changed, we need to inform {@link RestApi} to pause or
      * unpause devices and folders as defined in per-object sync preferences.
      */
-    private void onSyncPreconditionChanged() {
+    private void onSyncPreconditionChanged(RunConditionMonitor runConditionMonitor) {
-        if (mRestApi != null) {
+        synchronized (mStateLock) {
-            // Forward event.
+            if (mRestApi != null && mCurrentState == State.ACTIVE) {
-            mRestApi.onSyncPreconditionChanged(mRunConditionMonitor);
+                // Forward event because syncthing is running.
+                mRestApi.onSyncPreconditionChanged(runConditionMonitor);
+                return;
+            }
+        }
+
+        Log.v(TAG, "onSyncPreconditionChanged: Event fired while syncthing is not running.");
+        Boolean configChanged = false;
+        ConfigXml configXml;
+
+        // Read and parse the config from disk.
+        configXml = new ConfigXml(this);
+        try {
+            configXml.loadConfig();
+        } catch (ConfigXml.OpenConfigException e) {
+            mNotificationHandler.showCrashedNotification(R.string.config_read_failed, "onSyncPreconditionChanged:ConfigXml.OpenConfigException");
+            synchronized (mStateLock) {
+                onServiceStateChange(State.ERROR);
+            }
+            return;
+        }
+
+        // Check if the folders are available from config.
+        List<Folder> folders = configXml.getFolders();
+        if (folders != null) {
+            for (Folder folder : folders) {
+                // Log.v(TAG, "onSyncPreconditionChanged: Processing config of folder.id=" + folder.id);
+                Boolean folderCustomSyncConditionsEnabled = mPreferences.getBoolean(
+                    Constants.DYN_PREF_OBJECT_CUSTOM_SYNC_CONDITIONS(Constants.PREF_OBJECT_PREFIX_FOLDER + folder.id), false
+                );
+                if (folderCustomSyncConditionsEnabled) {
+                    Boolean syncConditionsMet = runConditionMonitor.checkObjectSyncConditions(
+                        Constants.PREF_OBJECT_PREFIX_FOLDER + folder.id
+                    );
+                    Log.v(TAG, "onSyncPreconditionChanged: syncFolder(" + folder.id + ")=" + (syncConditionsMet ? "1" : "0"));
+                    if (folder.paused != !syncConditionsMet) {
+                        configXml.setFolderPause(folder.id, !syncConditionsMet);
+                        Log.d(TAG, "onSyncPreconditionChanged: syncFolder(" + folder.id + ")=" + (syncConditionsMet ? ">1" : ">0"));
+                        configChanged = true;
+                    }
+                }
+            }
+        } else {
+            Log.d(TAG, "onSyncPreconditionChanged: folders == null");
+            return;
+        }
+
+        // Check if the devices are available from config.
+        List<Device> devices = configXml.getDevices(false);
+        if (devices != null) {
+            for (Device device : devices) {
+                // Log.v(TAG, "onSyncPreconditionChanged: Processing config of device.id=" + device.deviceID);
+                Boolean deviceCustomSyncConditionsEnabled = mPreferences.getBoolean(
+                    Constants.DYN_PREF_OBJECT_CUSTOM_SYNC_CONDITIONS(Constants.PREF_OBJECT_PREFIX_DEVICE + device.deviceID), false
+                );
+                if (deviceCustomSyncConditionsEnabled) {
+                    Boolean syncConditionsMet = runConditionMonitor.checkObjectSyncConditions(
+                        Constants.PREF_OBJECT_PREFIX_DEVICE + device.deviceID
+                    );
+                    Log.v(TAG, "onSyncPreconditionChanged: syncDevice(" + device.deviceID + ")=" + (syncConditionsMet ? "1" : "0"));
+                    if (device.paused != !syncConditionsMet) {
+                        configXml.setDevicePause(device.deviceID, !syncConditionsMet);
+                        Log.d(TAG, "onSyncPreconditionChanged: syncDevice(" + device.deviceID + ")=" + (syncConditionsMet ? ">1" : ">0"));
+                        configChanged = true;
+                    }
+                }
+            }
+        } else {
+            Log.d(TAG, "onSyncPreconditionChanged: devices == null");
+            return;
+        }
+
+        if (configChanged) {
+            Log.v(TAG, "onSyncPreconditionChanged: Saving changed config to disk ...");
+            configXml.saveChanges();
         }
     }
 
@@ -359,77 +456,25 @@ public class SyncthingService extends Service {
      * Prepares to launch the syncthing binary.
      */
     private void launchStartupTask(SyncthingRunnable.Command srCommand) {
-        Log.v(TAG, "Starting syncthing");
         synchronized (mStateLock) {
             if (mCurrentState != State.DISABLED && mCurrentState != State.INIT) {
                 Log.e(TAG, "launchStartupTask: Wrong state " + mCurrentState + " detected. Cancelling.");
                 return;
             }
         }
-
+        Log.v(TAG, "Starting syncthing");
-        // Safety check: Log warning if a previously launched startup task did not finish properly.
+        onServiceStateChange(State.STARTING);
-        if (mStartupTask != null && (mStartupTask.getStatus() == AsyncTask.Status.RUNNING)) {
+        mConfig = new ConfigXml(this);
-            Log.w(TAG, "launchStartupTask: StartupTask is still running. Skipped starting it twice.");
+        try {
+            mConfig.loadConfig();
+        } catch (ConfigXml.OpenConfigException e) {
+            mNotificationHandler.showCrashedNotification(R.string.config_read_failed, "ConfigXml.OpenConfigException");
+            synchronized (mStateLock) {
+                onServiceStateChange(State.ERROR);
+            }
             return;
         }
-        onServiceStateChange(State.STARTING);
-        mStartupTask = new StartupTask(this, srCommand);
-        mStartupTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
-    }
 
-    /**
-     * Sets up the initial configuration, and updates the config when coming from an old
-     * version.
-     */
-    private static class StartupTask extends AsyncTask<Void, Void, Void> {
-        private WeakReference<SyncthingService> refSyncthingService;
-        private SyncthingRunnable.Command srCommand;
-
-        StartupTask(SyncthingService context, SyncthingRunnable.Command srCommand) {
-            refSyncthingService = new WeakReference<>(context);
-            this.srCommand = srCommand;
-        }
-
-        @Override
-        protected Void doInBackground(Void... voids) {
-            SyncthingService syncthingService = refSyncthingService.get();
-            if (syncthingService == null) {
-                cancel(true);
-                return null;
-            }
-            try {
-                syncthingService.mConfig = new ConfigXml(syncthingService);
-                syncthingService.mConfig.updateIfNeeded();
-            } catch (SyncthingRunnable.ExecutableNotFoundException e) {
-                syncthingService.mNotificationHandler.showCrashedNotification(R.string.config_read_failed, "SycnthingRunnable.ExecutableNotFoundException");
-                synchronized (syncthingService.mStateLock) {
-                    syncthingService.onServiceStateChange(State.ERROR);
-                }
-                cancel(true);
-            } catch (ConfigXml.OpenConfigException e) {
-                syncthingService.mNotificationHandler.showCrashedNotification(R.string.config_read_failed, "ConfigXml.OpenConfigException");
-                synchronized (syncthingService.mStateLock) {
-                    syncthingService.onServiceStateChange(State.ERROR);
-                }
-                cancel(true);
-            }
-            return null;
-        }
-
-        @Override
-        protected void onPostExecute(Void aVoid) {
-            // Get a reference to the service if it is still there.
-            SyncthingService syncthingService = refSyncthingService.get();
-            if (syncthingService != null) {
-                syncthingService.onStartupTaskCompleteListener(srCommand);
-            }
-        }
-    }
-
-    /**
-     * Callback on {@link StartupTask#onPostExecute}.
-     */
-    private void onStartupTaskCompleteListener(SyncthingRunnable.Command srCommand) {
         if (mRestApi == null) {
             mRestApi = new RestApi(this, mConfig.getWebGuiUrl(), mConfig.getApiKey(),
                     this::onApiAvailable, () -> onServiceStateChange(mCurrentState));
@@ -652,13 +697,13 @@ public class SyncthingService extends Service {
         mCurrentState = newState;
         mHandler.post(() -> {
             mNotificationHandler.updatePersistentNotification(this);
-            for (Iterator<OnServiceStateChangeListener> i = mOnServiceStateChangeListeners.iterator();
+            Iterator<OnServiceStateChangeListener> it = mOnServiceStateChangeListeners.iterator();
-                 i.hasNext(); ) {
+            while (it.hasNext()) {
-                OnServiceStateChangeListener listener = i.next();
+                OnServiceStateChangeListener listener = it.next();
                 if (listener != null) {
                     listener.onServiceStateChange(mCurrentState);
                 } else {
-                    i.remove();
+                    it.remove();
                 }
             }
         });
@@ -773,7 +818,14 @@ public class SyncthingService extends Service {
 
         // Start syncthing after export if run conditions apply.
         if (mLastDeterminedShouldRun) {
-            launchStartupTask(SyncthingRunnable.Command.main);
+            Handler mainLooper = new Handler(Looper.getMainLooper());
+            Runnable launchStartupTaskRunnable = new Runnable() {
+                @Override
+                public void run() {
+                    launchStartupTask(SyncthingRunnable.Command.main);
+                }
+            };
+            mainLooper.post(launchStartupTaskRunnable);
         }
         return failSuccess;
     }
@@ -844,6 +896,7 @@ public class SyncthingService extends Service {
                         case Constants.PREF_DEBUG_FACILITIES_AVAILABLE:
                         case Constants.PREF_EVENT_PROCESSOR_LAST_SYNC_ID:
                         case Constants.PREF_LAST_BINARY_VERSION:
+                        case Constants.PREF_LOCAL_DEVICE_ID:
                             Log.v(TAG, "importConfig: Ignoring cache pref \"" + prefKey + "\".");
                             break;
                         default:
@@ -929,7 +982,14 @@ public class SyncthingService extends Service {
 
         // Start syncthing after import if run conditions apply.
         if (mLastDeterminedShouldRun) {
-            launchStartupTask(SyncthingRunnable.Command.main);
+            Handler mainLooper = new Handler(Looper.getMainLooper());
+            Runnable launchStartupTaskRunnable = new Runnable() {
+                @Override
+                public void run() {
+                    launchStartupTask(SyncthingRunnable.Command.main);
+                }
+            };
+            mainLooper.post(launchStartupTaskRunnable);
         }
         return failSuccess;
     }

app/src/main/java/com/nutomic/syncthingandroid/util/ConfigRouter.java

@@ -0,0 +1,166 @@
+package com.nutomic.syncthingandroid.util;
+
+import android.content.Context;
+// import android.util.Log;
+
+import com.nutomic.syncthingandroid.model.Device;
+import com.nutomic.syncthingandroid.model.Folder;
+import com.nutomic.syncthingandroid.model.FolderIgnoreList;
+import com.nutomic.syncthingandroid.service.RestApi;
+import com.nutomic.syncthingandroid.util.ConfigXml;
+
+import java.util.List;
+
+/**
+ * Provides a transparent access to the config if ...
+ * a) Syncthing is running and REST API is available.
+ * b) Syncthing is NOT running and config.xml is accessed.
+ */
+public class ConfigRouter {
+
+    private static final String TAG = "ConfigRouter";
+
+    public interface OnResultListener1<T> {
+        void onResult(T t);
+    }
+
+    private final Context mContext;
+
+    private ConfigXml configXml;
+
+    public ConfigRouter(Context context) {
+        mContext = context;
+        configXml = new ConfigXml(mContext);
+    }
+
+    public List<Folder> getFolders(RestApi restApi) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            return configXml.getFolders();
+        }
+
+        // Syncthing is running and REST API is available.
+        return restApi.getFolders();
+    }
+
+    public void addFolder(RestApi restApi, Folder folder) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            configXml.addFolder(folder);
+            configXml.saveChanges();
+            return;
+        }
+
+        // Syncthing is running and REST API is available.
+        restApi.addFolder(folder);       // This will send the config afterwards.
+    }
+
+    public void updateFolder(RestApi restApi, final Folder folder) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            configXml.updateFolder(folder);
+            configXml.saveChanges();
+            return;
+        }
+
+        // Syncthing is running and REST API is available.
+        restApi.updateFolder(folder);       // This will send the config afterwards.
+    }
+
+    public void removeFolder(RestApi restApi, final String folderId) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            configXml.removeFolder(folderId);
+            configXml.saveChanges();
+            return;
+        }
+
+        // Syncthing is running and REST API is available.
+        restApi.removeFolder(folderId);       // This will send the config afterwards.
+    }
+
+    /**
+     * Gets ignore list for given folder.
+     */
+    public void getFolderIgnoreList(RestApi restApi, Folder folder, OnResultListener1<FolderIgnoreList> listener) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            configXml.getFolderIgnoreList(folder, folderIgnoreList -> listener.onResult(folderIgnoreList));
+            return;
+        }
+
+        // Syncthing is running and REST API is available.
+        restApi.getFolderIgnoreList(folder.id, folderIgnoreList -> listener.onResult(folderIgnoreList));
+    }
+
+    /**
+     * Stores ignore list for given folder.
+     */
+    public void postFolderIgnoreList(RestApi restApi, Folder folder, String[] ignore) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            configXml.postFolderIgnoreList(folder, ignore);
+            return;
+        }
+
+        // Syncthing is running and REST API is available.
+        restApi.postFolderIgnoreList(folder.id, ignore);
+    }
+
+    public List<Device> getDevices(RestApi restApi, Boolean includeLocal) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            return configXml.getDevices(includeLocal);
+        }
+
+        // Syncthing is running and REST API is available.
+        return restApi.getDevices(includeLocal);
+    }
+
+    public void addDevice(RestApi restApi, Device device, OnResultListener1<String> errorListener) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            configXml.addDevice(device, error -> errorListener.onResult(error));
+            configXml.saveChanges();
+            return;
+        }
+
+        // Syncthing is running and REST API is available.
+        restApi.addDevice(device, error -> errorListener.onResult(error));       // This will send the config afterwards.
+    }
+
+    public void updateDevice(RestApi restApi, final Device device) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            configXml.updateDevice(device);
+            configXml.saveChanges();
+            return;
+        }
+
+        // Syncthing is running and REST API is available.
+        restApi.updateDevice(device);       // This will send the config afterwards.
+    }
+
+    public void removeDevice(RestApi restApi, final String deviceID) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running or REST API is not (yet) available.
+            configXml.loadConfig();
+            configXml.removeDevice(deviceID);
+            configXml.saveChanges();
+            return;
+        }
+
+        // Syncthing is running and REST API is available.
+        restApi.removeDevice(deviceID);       // This will send the config afterwards.
+    }
+
+}

app/src/main/java/com/nutomic/syncthingandroid/util/ConfigXml.java

@@ -1,13 +1,15 @@
 package com.nutomic.syncthingandroid.util;
 
 import android.content.Context;
-import android.content.SharedPreferences;
 import android.os.Build;
 import android.os.Environment;
 import android.preference.PreferenceManager;
 import android.text.TextUtils;
 import android.util.Log;
 
+import com.nutomic.syncthingandroid.model.Device;
+import com.nutomic.syncthingandroid.model.Folder;
+import com.nutomic.syncthingandroid.model.FolderIgnoreList;
 import com.nutomic.syncthingandroid.R;
 import com.nutomic.syncthingandroid.service.Constants;
 import com.nutomic.syncthingandroid.service.SyncthingRunnable;
@@ -23,12 +25,16 @@ import java.io.OutputStreamWriter;
 import java.io.UnsupportedEncodingException;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Random;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import javax.inject.Inject;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
@@ -53,53 +59,117 @@ import org.xml.sax.InputSource;
  */
 public class ConfigXml {
 
+    private static final String TAG = "ConfigXml";
+
+    private static final Boolean ENABLE_VERBOSE_LOG = false;
+
     public class OpenConfigException extends RuntimeException {
     }
 
-    private static final String TAG = "ConfigXml";
+    /**
+     * Compares devices by name, uses the device ID as fallback if the name is empty
+     */
+    private final static Comparator<Device> DEVICES_COMPARATOR = (lhs, rhs) -> {
+        String lhsName = lhs.name != null && !lhs.name.isEmpty() ? lhs.name : lhs.deviceID;
+        String rhsName = rhs.name != null && !rhs.name.isEmpty() ? rhs.name : rhs.deviceID;
+        return lhsName.compareTo(rhsName);
+    };
+
+    /**
+     * Compares folders by labels, uses the folder ID as fallback if the label is empty
+     */
+    private final static Comparator<Folder> FOLDERS_COMPARATOR = (lhs, rhs) -> {
+        String lhsLabel = lhs.label != null && !lhs.label.isEmpty() ? lhs.label : lhs.id;
+        String rhsLabel = rhs.label != null && !rhs.label.isEmpty() ? rhs.label : rhs.id;
+        return lhsLabel.compareTo(rhsLabel);
+    };
+
+    public interface OnResultListener1<T> {
+        void onResult(T t);
+    }
+
     private static final int FOLDER_ID_APPENDIX_LENGTH = 4;
 
     private final Context mContext;
 
-    @Inject
-    SharedPreferences mPreferences;
-
     private final File mConfigFile;
 
     private Document mConfig;
 
-    public ConfigXml(Context context) throws OpenConfigException, SyncthingRunnable.ExecutableNotFoundException {
+    public ConfigXml(Context context) {
         mContext = context;
         mConfigFile = Constants.getConfigFile(mContext);
-        boolean isFirstStart = !mConfigFile.exists();
+    }
-        if (isFirstStart) {
+
-            Log.i(TAG, "App started for the first time. Generating keys and config.");
+    public void loadConfig() throws OpenConfigException {
-            new SyncthingRunnable(context, SyncthingRunnable.Command.generate).run(true);
+        parseConfig();
+        updateIfNeeded();
+    }
+
+    /**
+     * This should run within an AsyncTask as it can cause a full CPU load
+     * for more than 30 seconds on older phone hardware.
+     */
+    public void generateConfig() throws OpenConfigException, SyncthingRunnable.ExecutableNotFoundException {
+        // Create new secret keys and config.
+        Log.i(TAG, "(Re)Generating keys and config.");
+        new SyncthingRunnable(mContext, SyncthingRunnable.Command.generate).run(true);
+        parseConfig();
+        Boolean changed = false;
+
+        // Set local device name.
+        Log.i(TAG, "Starting syncthing to retrieve local device id.");
+        String localDeviceID = getLocalDeviceIDandStoreToPref();
+        if (!TextUtils.isEmpty(localDeviceID)) {
+            changed = changeLocalDeviceName(localDeviceID) || changed;
         }
 
-        readConfig();
+        // Set default folder to the "camera" folder: path and name
+        changed = changeDefaultFolder() || changed;
 
-        if (isFirstStart) {
+        // Save changes if we made any.
-            boolean changed = false;
+        if (changed) {
-
+            saveChanges();
-            Log.i(TAG, "Starting syncthing to retrieve local device id.");
-            String logOutput = new SyncthingRunnable(context, SyncthingRunnable.Command.deviceid).run(true);
-            String localDeviceID = logOutput.replace("\n", "");
-            // Verify local device ID is correctly formatted.
-            if (localDeviceID.matches("^([A-Z0-9]{7}-){7}[A-Z0-9]{7}$")) {
-                changed = changeLocalDeviceName(localDeviceID) || changed;
-            }
-            changed = changeDefaultFolder() || changed;
-
-            // Save changes if we made any.
-            if (changed) {
-                saveChanges();
-            }
         }
     }
 
-    private void readConfig() {
+    private String getLocalDeviceIDfromPref() {
+        String localDeviceID = PreferenceManager.getDefaultSharedPreferences(mContext).getString(Constants.PREF_LOCAL_DEVICE_ID, "");
+        if (TextUtils.isEmpty(localDeviceID)) {
+            Log.d(TAG, "getLocalDeviceIDfromPref: Local device ID unavailable, trying to retrieve it from syncthing ...");
+            try {
+                localDeviceID = getLocalDeviceIDandStoreToPref();
+            } catch (SyncthingRunnable.ExecutableNotFoundException e) {
+                Log.e(TAG, "getLocalDeviceIDfromPref: Failed to execute syncthing core");
+            }
+            if (TextUtils.isEmpty(localDeviceID)) {
+                Log.e(TAG, "getLocalDeviceIDfromPref: Local device ID unavailable");
+            }
+        }
+        return localDeviceID;
+    }
+
+    private String getLocalDeviceIDandStoreToPref() throws SyncthingRunnable.ExecutableNotFoundException {
+        String logOutput = new SyncthingRunnable(mContext, SyncthingRunnable.Command.deviceid).run(true);
+        String localDeviceID = logOutput.replace("\n", "");
+
+        // Verify that local device ID is correctly formatted.
+        if (!isDeviceIdValid(localDeviceID)) {
+            Log.w(TAG, "getLocalDeviceIDandStoreToPref: Syncthing core returned a bad formatted device ID \"" + localDeviceID + "\"");
+            return "";
+        }
+
+        // Store local device ID to pref. This saves us expensive calls to the syncthing binary if we need it later.
+        PreferenceManager.getDefaultSharedPreferences(mContext).edit()
+            .putString(Constants.PREF_LOCAL_DEVICE_ID, localDeviceID)
+            .apply();
+        Log.v(TAG, "getLocalDeviceIDandStoreToPref: Cached local device ID \"" + localDeviceID + "\"");
+        return localDeviceID;
+    }
+
+    private void parseConfig() {
         if (!mConfigFile.canRead() && !Util.fixAppDataPermissions(mContext)) {
+            Log.w(TAG, "Failed to open config file '" + mConfigFile + "'");
             throw new OpenConfigException();
         }
         try {
@@ -107,11 +177,16 @@ public class ConfigXml {
             InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "UTF-8");
             InputSource inputSource = new InputSource(inputStreamReader);
             inputSource.setEncoding("UTF-8");
-            DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
+            DocumentBuilderFactory dbfactory = DocumentBuilderFactory.newInstance();
-            Log.d(TAG, "Parsing config file '" + mConfigFile + "'");
+            DocumentBuilder db = dbfactory.newDocumentBuilder();
+            if (ENABLE_VERBOSE_LOG) {
+                Log.v(TAG, "Parsing config file '" + mConfigFile + "'");
+            }
             mConfig = db.parse(inputSource);
             inputStream.close();
-            Log.i(TAG, "Successfully parsed config file");
+            if (ENABLE_VERBOSE_LOG) {
+                Log.v(TAG, "Successfully parsed config file");
+            }
         } catch (SAXException | ParserConfigurationException | IOException e) {
             Log.w(TAG, "Failed to parse config file '" + mConfigFile + "'", e);
             throw new OpenConfigException();
@@ -141,7 +216,7 @@ public class ConfigXml {
      * username/password, and disables weak hash checking.
      */
     @SuppressWarnings("SdCardPath")
-    public void updateIfNeeded() {
+    private void updateIfNeeded() {
         boolean changed = false;
 
         /* Perform one-time migration tasks on syncthing's config file when coming from an older config version. */
@@ -173,7 +248,7 @@ public class ConfigXml {
         Boolean forceHttps = Constants.osSupportsTLS12();
         if (!gui.hasAttribute("tls") ||
                 Boolean.parseBoolean(gui.getAttribute("tls")) != forceHttps) {
-            gui.setAttribute("tls", forceHttps ? "true" : "false");
+            gui.setAttribute("tls", Boolean.toString(forceHttps));
             changed = true;
         }
 
@@ -222,6 +297,9 @@ public class ConfigXml {
             }
         }
 
+        // Disable "startBrowser" because it applies to desktop environments and cannot start a mobile browser app.
+        changed = setConfigElement(options, "startBrowser", "false") || changed;
+
         // Save changes if we made any.
         if (changed) {
             saveChanges();
@@ -238,7 +316,9 @@ public class ConfigXml {
         /* Read existing config version */
         int iConfigVersion = Integer.parseInt(mConfig.getDocumentElement().getAttribute("version"));
         int iOldConfigVersion = iConfigVersion;
-        Log.i(TAG, "Found existing config version " + Integer.toString(iConfigVersion));
+        if (ENABLE_VERBOSE_LOG) {
+            Log.v(TAG, "Found existing config version " + Integer.toString(iConfigVersion));
+        }
 
         /* Check if we have to do manual migration from version X to Y */
         if (iConfigVersion == 27) {
@@ -273,6 +353,438 @@ public class ConfigXml {
         }
     }
 
+    private Boolean getAttributeOrDefault(final Element element, String attribute, Boolean defaultValue) {
+        return element.hasAttribute(attribute) ? Boolean.parseBoolean(element.getAttribute(attribute)) : defaultValue;
+    }
+
+    private Integer getAttributeOrDefault(final Element element, String attribute, Integer defaultValue) {
+        return element.hasAttribute(attribute) ? Integer.parseInt(element.getAttribute(attribute)) : defaultValue;
+    }
+
+    private String getAttributeOrDefault(final Element element, String attribute, String defaultValue) {
+        return element.hasAttribute(attribute) ? element.getAttribute(attribute) : defaultValue;
+    }
+
+    private Boolean getContentOrDefault(final Node node, Boolean defaultValue) {
+         return (node == null) ? defaultValue : Boolean.parseBoolean(node.getTextContent());
+    }
+
+    private Integer getContentOrDefault(final Node node, Integer defaultValue) {
+         return (node == null) ? defaultValue : Integer.parseInt(node.getTextContent());
+    }
+
+    private String getContentOrDefault(final Node node, String defaultValue) {
+         return (node == null) ? defaultValue : node.getTextContent();
+    }
+
+    public List<Folder> getFolders() {
+        String localDeviceID = getLocalDeviceIDfromPref();
+        List<Folder> folders = new ArrayList<>();
+        NodeList nodeFolders = mConfig.getDocumentElement().getElementsByTagName("folder");
+        for (int i = 0; i < nodeFolders.getLength(); i++) {
+            Element r = (Element) nodeFolders.item(i);
+            Folder folder = new Folder();
+            folder.id = getAttributeOrDefault(r, "id", "");
+            folder.label = getAttributeOrDefault(r, "label", "");
+            folder.path = getAttributeOrDefault(r, "path", "");
+            folder.type = getAttributeOrDefault(r, "type", Constants.FOLDER_TYPE_SEND_RECEIVE);
+            folder.autoNormalize = getAttributeOrDefault(r, "autoNormalize", true);
+            folder.fsWatcherDelayS =getAttributeOrDefault(r, "fsWatcherDelayS", 10);
+            folder.fsWatcherEnabled = getAttributeOrDefault(r, "fsWatcherEnabled", true);
+            folder.ignorePerms = getAttributeOrDefault(r, "ignorePerms", true);
+            folder.rescanIntervalS = getAttributeOrDefault(r, "rescanIntervalS", 3600);
+
+            folder.copiers = getContentOrDefault(r.getElementsByTagName("copiers").item(0), 0);
+            folder.hashers = getContentOrDefault(r.getElementsByTagName("hashers").item(0), 0);
+            folder.order = getContentOrDefault(r.getElementsByTagName("order").item(0), "random");
+            folder.paused = getContentOrDefault(r.getElementsByTagName("paused").item(0), false);
+
+            // Devices
+            /*
+            <device id="[DEVICE_ID]" introducedBy=""/>
+            */
+            NodeList nodeDevices = r.getElementsByTagName("device");
+            for (int j = 0; j < nodeDevices.getLength(); j++) {
+                Element elementDevice = (Element) nodeDevices.item(j);
+                Device device = new Device();
+                device.deviceID = getAttributeOrDefault(elementDevice, "id", "");
+
+                // Exclude self.
+                if (!TextUtils.isEmpty(device.deviceID) && !device.deviceID.equals(localDeviceID)) {
+                    device.introducedBy = getAttributeOrDefault(elementDevice, "introducedBy", "");
+                    // Log.v(TAG, "getFolders: deviceID=" + device.deviceID + ", introducedBy=" + device.introducedBy);
+                    folder.addDevice(device);
+                }
+            }
+
+            // Versioning
+            /*
+            <versioning></versioning>
+            <versioning type="trashcan">
+                <param key="cleanoutDays" val="90"></param>
+            </versioning>
+            */
+            folder.versioning = new Folder.Versioning();
+            Element elementVersioning = (Element) r.getElementsByTagName("versioning").item(0);
+            folder.versioning.type = getAttributeOrDefault(elementVersioning, "type", "");
+            NodeList nodeVersioningParam = elementVersioning.getElementsByTagName("param");
+            for (int j = 0; j < nodeVersioningParam.getLength(); j++) {
+                Element elementVersioningParam = (Element) nodeVersioningParam.item(j);
+                folder.versioning.params.put(
+                        getAttributeOrDefault(elementVersioningParam, "key", ""),
+                        getAttributeOrDefault(elementVersioningParam, "val", "")
+                );
+                /*
+                Log.v(TAG, "folder.versioning.type=" + folder.versioning.type +
+                        ", key=" + getAttributeOrDefault(elementVersioningParam, "key", "") +
+                        ", val=" + getAttributeOrDefault(elementVersioningParam, "val", "")
+                );
+                */
+            }
+
+            // For testing purposes only.
+            // Log.v(TAG, "folder.label=" + folder.label + "/" +"folder.type=" + folder.type + "/" + "folder.paused=" + folder.paused);
+            folders.add(folder);
+        }
+        Collections.sort(folders, FOLDERS_COMPARATOR);
+        return folders;
+    }
+
+    public void addFolder(final Folder folder) {
+        Log.v(TAG, "addFolder: folder.id=" + folder.id);
+        Node nodeConfig = mConfig.getDocumentElement();
+        Node nodeFolder = mConfig.createElement("folder");
+        nodeConfig.appendChild(nodeFolder);
+        Element elementFolder = (Element) nodeFolder;
+        elementFolder.setAttribute("id", folder.id);
+        updateFolder(folder);
+    }
+
+    public void updateFolder(final Folder folder) {
+        String localDeviceID = getLocalDeviceIDfromPref();
+        NodeList nodeFolders = mConfig.getDocumentElement().getElementsByTagName("folder");
+        for (int i = 0; i < nodeFolders.getLength(); i++) {
+            Element r = (Element) nodeFolders.item(i);
+            if (folder.id.equals(getAttributeOrDefault(r, "id", ""))) {
+                // Found folder node to update.
+                r.setAttribute("label", folder.label);
+                r.setAttribute("path", folder.path);
+                r.setAttribute("type", folder.type);
+                r.setAttribute("autoNormalize", Boolean.toString(folder.autoNormalize));
+                r.setAttribute("fsWatcherDelayS", Integer.toString(folder.fsWatcherDelayS));
+                r.setAttribute("fsWatcherEnabled", Boolean.toString(folder.fsWatcherEnabled));
+                r.setAttribute("ignorePerms", Boolean.toString(folder.ignorePerms));
+                r.setAttribute("rescanIntervalS", Integer.toString(folder.rescanIntervalS));
+
+                setConfigElement(r, "copiers", Integer.toString(folder.copiers));
+                setConfigElement(r, "hashers", Integer.toString(folder.hashers));
+                setConfigElement(r, "order", folder.order);
+                setConfigElement(r, "paused", Boolean.toString(folder.paused));
+
+                // Update devices that share this folder.
+                // Pass 1: Remove all devices below that folder in XML except the local device.
+                NodeList nodeDevices = r.getElementsByTagName("device");
+                for (int j = nodeDevices.getLength() - 1; j >= 0; j--) {
+                    Element elementDevice = (Element) nodeDevices.item(j);
+                    if (!getAttributeOrDefault(elementDevice, "id", "").equals(localDeviceID)) {
+                        Log.v(TAG, "updateFolder: nodeDevices: Removing deviceID=" + getAttributeOrDefault(elementDevice, "id", ""));
+                        removeChildElementFromTextNode(r, elementDevice);
+                    }
+                }
+
+                // Pass 2: Add devices below that folder from the POJO model.
+                final List<Device> devices = folder.getDevices();
+                for (Device device : devices) {
+                    Log.v(TAG, "updateFolder: nodeDevices: Adding deviceID=" + device.deviceID);
+                    Node nodeDevice = mConfig.createElement("device");
+                    r.appendChild(nodeDevice);
+                    Element elementDevice = (Element) nodeDevice;
+                    elementDevice.setAttribute("id", device.deviceID);
+                    elementDevice.setAttribute("introducedBy", device.introducedBy);
+                }
+
+                // Versioning
+                // Pass 1: Remove all versioning nodes in XML (usually one)
+                /*
+                NodeList nlVersioning = r.getElementsByTagName("versioning");
+                for (int j = nlVersioning.getLength() - 1; j >= 0; j--) {
+                    Log.v(TAG, "updateFolder: nodeVersioning: Removing versioning node");
+                    removeChildElementFromTextNode(r, (Element) nlVersioning.item(j));
+                }
+                */
+                Element elementVersioning = (Element) r.getElementsByTagName("versioning").item(0);
+                if (elementVersioning != null) {
+                    Log.v(TAG, "updateFolder: nodeVersioning: Removing versioning node");
+                    removeChildElementFromTextNode(r, elementVersioning);
+                }
+
+                // Pass 2: Add versioning node from the POJO model.
+                Node nodeVersioning = mConfig.createElement("versioning");
+                r.appendChild(nodeVersioning);
+                elementVersioning = (Element) nodeVersioning;
+                if (!TextUtils.isEmpty(folder.versioning.type)) {
+                    elementVersioning.setAttribute("type", folder.versioning.type);
+                    for (Map.Entry<String, String> param : folder.versioning.params.entrySet()) {
+                        Log.v(TAG, "updateFolder: nodeVersioning: Adding param key=" + param.getKey() + ", val=" + param.getValue());
+                        Node nodeParam = mConfig.createElement("param");
+                        elementVersioning.appendChild(nodeParam);
+                        Element elementParam = (Element) nodeParam;
+                        elementParam.setAttribute("key", param.getKey());
+                        elementParam.setAttribute("val", param.getValue());
+                    }
+                }
+
+                break;
+            }
+        }
+    }
+
+    public void removeFolder(String folderId) {
+        NodeList nodeFolders = mConfig.getDocumentElement().getElementsByTagName("folder");
+        for (int i = nodeFolders.getLength() - 1; i >= 0; i--) {
+            Element r = (Element) nodeFolders.item(i);
+            if (folderId.equals(getAttributeOrDefault(r, "id", ""))) {
+                // Found folder node to remove.
+                Log.v(TAG, "removeFolder: Removing folder node, folderId=" + folderId);
+                removeChildElementFromTextNode((Element) r.getParentNode(), r);
+                break;
+            }
+        }
+    }
+
+    public void setFolderPause(String folderId, Boolean paused) {
+        NodeList nodeFolders = mConfig.getDocumentElement().getElementsByTagName("folder");
+        for (int i = 0; i < nodeFolders.getLength(); i++) {
+            Element r = (Element) nodeFolders.item(i);
+            if (getAttributeOrDefault(r, "id", "").equals(folderId))
+            {
+                setConfigElement(r, "paused", Boolean.toString(paused));
+                break;
+            }
+        }
+    }
+
+    /**
+     * Gets ignore list for given folder.
+     */
+    public void getFolderIgnoreList(Folder folder, OnResultListener1<FolderIgnoreList> listener) {
+        FolderIgnoreList folderIgnoreList = new FolderIgnoreList();
+        File file;
+        FileInputStream fileInputStream = null;
+        try {
+            file = new File(folder.path, ".stignore");
+            if (file.exists()) {
+                fileInputStream = new FileInputStream(file);
+                InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream, "UTF-8");
+                byte[] data = new byte[(int) file.length()];
+                fileInputStream.read(data);
+                folderIgnoreList.ignore = new String(data, "UTF-8").split("\n");
+            } else {
+                // File not found.
+                Log.w(TAG, "getFolderIgnoreList: File missing " + file);
+                /**
+                 * Don't fail as the file might be expectedly missing when users didn't
+                 * set ignores in the past storyline of that folder.
+                 */
+            }
+        } catch (IOException e) {
+            Log.e(TAG, "getFolderIgnoreList: Failed to read '" + folder.path + "/.stignore' #1", e);
+        } finally {
+            try {
+                if (fileInputStream != null) {
+                    fileInputStream.close();
+                }
+            } catch (IOException e) {
+                Log.e(TAG, "getFolderIgnoreList: Failed to read '" + folder.path + "/.stignore' #2", e);
+            }
+        }
+        listener.onResult(folderIgnoreList);
+    }
+
+    /**
+     * Stores ignore list for given folder.
+     */
+    public void postFolderIgnoreList(Folder folder, String[] ignore) {
+        File file;
+        FileOutputStream fileOutputStream = null;
+        try {
+            file = new File(folder.path, ".stignore");
+            if (!file.exists()) {
+                file.createNewFile();
+            }
+            fileOutputStream = new FileOutputStream(file);
+            // Log.v(TAG, "postFolderIgnoreList: Writing .stignore content=" + TextUtils.join("\n", ignore));
+            fileOutputStream.write(TextUtils.join("\n", ignore).getBytes("UTF-8"));
+            fileOutputStream.flush();
+        } catch (IOException e) {
+            /**
+             * This will happen on external storage folders which exist outside the
+             * "/Android/data/[package_name]/files" folder on Android 5+.
+             */
+            Log.w(TAG, "postFolderIgnoreList: Failed to write '" + folder.path + "/.stignore' #1", e);
+        } finally {
+            try {
+                if (fileOutputStream != null) {
+                    fileOutputStream.close();
+                }
+            } catch (IOException e) {
+                Log.e(TAG, "postFolderIgnoreList: Failed to write '" + folder.path + "/.stignore' #2", e);
+            }
+        }
+    }
+
+    public List<Device> getDevices(Boolean includeLocal) {
+        String localDeviceID = getLocalDeviceIDfromPref();
+        List<Device> devices = new ArrayList<>();
+
+        // Prevent enumerating "<device>" tags below "<folder>" nodes by enumerating child nodes manually.
+        NodeList childNodes = mConfig.getDocumentElement().getChildNodes();
+        for (int i = 0; i < childNodes.getLength(); i++) {
+            Node node = childNodes.item(i);
+            if (node.getNodeName().equals("device")) {
+                Element r = (Element) node;
+                Device device = new Device();
+                device.compression = getAttributeOrDefault(r, "compression", "metadata");
+                device.deviceID = getAttributeOrDefault(r, "id", "");
+                device.introducedBy = getAttributeOrDefault(r, "introducedBy", "");
+                device.introducer =  getAttributeOrDefault(r, "introducer", false);
+                device.name = getAttributeOrDefault(r, "name", "");
+                device.paused = getContentOrDefault(r.getElementsByTagName("paused").item(0), false);
+
+                // Addresses
+                /*
+                <device ...>
+                    <address>dynamic</address>
+                    <address>tcp4://192.168.1.67:2222</address>
+                </device>
+                */
+                device.addresses = new ArrayList<>();
+                NodeList nodeAddresses = r.getElementsByTagName("address");
+                for (int j = 0; j < nodeAddresses.getLength(); j++) {
+                    String address = getContentOrDefault(nodeAddresses.item(j), "");
+                    device.addresses.add(address);
+                    // Log.v(TAG, "getDevices: address=" + address);
+                }
+
+                // For testing purposes only.
+                // Log.v(TAG, "getDevices: device.name=" + device.name + "/" +"device.id=" + device.deviceID + "/" + "device.paused=" + device.paused);
+
+                // Exclude self if requested.
+                Boolean isLocalDevice = !TextUtils.isEmpty(device.deviceID) && device.deviceID.equals(localDeviceID);
+                if (includeLocal || !isLocalDevice) {
+                    devices.add(device);
+                }
+            }
+        }
+        Collections.sort(devices, DEVICES_COMPARATOR);
+        return devices;
+    }
+
+    public void addDevice(final Device device, OnResultListener1<String> errorListener) {
+        if (!isDeviceIdValid(device.deviceID)) {
+            errorListener.onResult(mContext.getString(R.string.device_id_invalid));
+            return;
+        }
+
+        Log.v(TAG, "addDevice: deviceID=" + device.deviceID);
+        Node nodeConfig = mConfig.getDocumentElement();
+        Node nodeDevice = mConfig.createElement("device");
+        nodeConfig.appendChild(nodeDevice);
+        Element elementDevice = (Element) nodeDevice;
+        elementDevice.setAttribute("id", device.deviceID);
+        updateDevice(device);
+    }
+
+    public void updateDevice(final Device device) {
+        // Prevent enumerating "<device>" tags below "<folder>" nodes by enumerating child nodes manually.
+        NodeList childNodes = mConfig.getDocumentElement().getChildNodes();
+        for (int i = 0; i < childNodes.getLength(); i++) {
+            Node node = childNodes.item(i);
+            if (node.getNodeName().equals("device")) {
+                Element r = (Element) node;
+                if (device.deviceID.equals(getAttributeOrDefault(r, "id", ""))) {
+                    // Found device to update.
+                    r.setAttribute("compression", device.compression);
+                    r.setAttribute("introducedBy", device.introducedBy);
+                    r.setAttribute("introducer", Boolean.toString(device.introducer));
+                    r.setAttribute("name", device.name);
+
+                    setConfigElement(r, "paused", Boolean.toString(device.paused));
+
+                    // Addresses
+                    // Pass 1: Remove all addresses in XML.
+                    NodeList nodeAddresses = r.getElementsByTagName("address");
+                    for (int j = nodeAddresses.getLength() - 1; j >= 0; j--) {
+                        Element elementAddress = (Element) nodeAddresses.item(j);
+                        Log.v(TAG, "updateDevice: nodeAddresses: Removing address=" + getContentOrDefault(elementAddress, ""));
+                        removeChildElementFromTextNode(r, elementAddress);
+                    }
+
+                    // Pass 2: Add addresses from the POJO model.
+                    if (device.addresses != null) {
+                        for (String address : device.addresses) {
+                            Log.v(TAG, "updateDevice: nodeAddresses: Adding address=" + address);
+                            Node nodeAddress = mConfig.createElement("address");
+                            r.appendChild(nodeAddress);
+                            Element elementAddress = (Element) nodeAddress;
+                            elementAddress.setTextContent(address);
+                        }
+                    }
+
+                    break;
+                }
+            }
+        }
+    }
+
+    public void removeDevice(String deviceID) {
+        // Prevent enumerating "<device>" tags below "<folder>" nodes by enumerating child nodes manually.
+        NodeList childNodes = mConfig.getDocumentElement().getChildNodes();
+        for (int i = 0; i < childNodes.getLength(); i++) {
+            Node node = childNodes.item(i);
+            if (node.getNodeName().equals("device")) {
+                Element r = (Element) node;
+                if (deviceID.equals(getAttributeOrDefault(r, "id", ""))) {
+                    // Found device to remove.
+                    Log.v(TAG, "removeDevice: Removing device node, deviceID=" + deviceID);
+                    removeChildElementFromTextNode((Element) r.getParentNode(), r);
+                    break;
+                }
+            }
+        }
+    }
+
+    public void setDevicePause(String deviceId, Boolean paused) {
+        // Prevent enumerating "<device>" tags below "<folder>" nodes by enumerating child nodes manually.
+        NodeList childNodes = mConfig.getDocumentElement().getChildNodes();
+        for (int i = 0; i < childNodes.getLength(); i++) {
+            Node node = childNodes.item(i);
+            if (node.getNodeName().equals("device")) {
+                Element r = (Element) node;
+                if (getAttributeOrDefault(r, "id", "").equals(deviceId))
+                {
+                    setConfigElement(r, "paused", Boolean.toString(paused));
+                    break;
+                }
+            }
+        }
+    }
+
+    /**
+     * If an indented child element is removed, whitespace and line break will be left by
+     * Element.removeChild().
+     * See https://stackoverflow.com/questions/14255064/removechild-how-to-remove-indent-too
+     */
+    private void removeChildElementFromTextNode(Element parentElement, Element childElement) {
+        Node prev = childElement.getPreviousSibling();
+        if (prev != null &&
+                prev.getNodeType() == Node.TEXT_NODE &&
+                prev.getNodeValue().trim().length() == 0) {
+            parentElement.removeChild(prev);
+        }
+        parentElement.removeChild(childElement);
+    }
+
     private boolean setConfigElement(Element parent, String tagName, String textContent) {
         Node element = parent.getElementsByTagName(tagName).item(0);
         if (element == null) {
@@ -347,16 +859,23 @@ public class ConfigXml {
         return sb.toString();
     }
 
+    /**
+     * Returns if a syncthing device ID is correctly formatted.
+     */
+    private Boolean isDeviceIdValid(final String deviceID) {
+        return deviceID.matches("^([A-Z0-9]{7}-){7}[A-Z0-9]{7}$");
+    }
+
     /**
      * Writes updated mConfig back to file.
      */
-    private void saveChanges() {
+    public void saveChanges() {
         if (!mConfigFile.canWrite() && !Util.fixAppDataPermissions(mContext)) {
             Log.w(TAG, "Failed to save updated config. Cannot change the owner of the config file.");
             return;
         }
 
-        Log.i(TAG, "Writing updated config file");
+        Log.i(TAG, "Saving config file");
         File mConfigTempFile = Constants.getConfigTempFile(mContext);
         try {
             // Write XML header.

app/src/main/java/com/nutomic/syncthingandroid/views/DevicesAdapter.java

@@ -4,6 +4,7 @@ import android.content.Context;
 import android.content.res.Resources;
 import android.support.annotation.NonNull;
 import android.support.v4.content.ContextCompat;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -16,11 +17,16 @@ import com.nutomic.syncthingandroid.model.Device;
 import com.nutomic.syncthingandroid.service.RestApi;
 import com.nutomic.syncthingandroid.util.Util;
 
+import static android.view.View.GONE;
+import static android.view.View.VISIBLE;
+
 /**
  * Generates item views for device items.
  */
 public class DevicesAdapter extends ArrayAdapter<Device> {
 
+    private static final String TAG = "DevicesAdapter";
+
     private Connections mConnections;
 
     public DevicesAdapter(Context context) {
@@ -36,6 +42,7 @@ public class DevicesAdapter extends ArrayAdapter<Device> {
             convertView = inflater.inflate(R.layout.item_device_list, parent, false);
         }
 
+        View rateInOutView = convertView.findViewById(R.id.rateInOutContainer);
         TextView name = convertView.findViewById(R.id.name);
         TextView status = convertView.findViewById(R.id.status);
         TextView download = convertView.findViewById(R.id.download);
@@ -52,16 +59,17 @@ public class DevicesAdapter extends ArrayAdapter<Device> {
         }
 
         if (conn == null) {
-            download.setText(Util.readableTransferRate(getContext(), 0));
+            // Syncthing is not running.
-            upload.setText(Util.readableTransferRate(getContext(), 0));
+            rateInOutView.setVisibility(GONE);
+            status.setVisibility(GONE);
             status.setText(r.getString(R.string.device_state_unknown));
             status.setTextColor(ContextCompat.getColor(getContext(), R.color.text_red));
             return convertView;
         }
 
         if (conn.paused) {
-            download.setText(Util.readableTransferRate(getContext(), 0));
+            rateInOutView.setVisibility(GONE);
-            upload.setText(Util.readableTransferRate(getContext(), 0));
+            status.setVisibility(VISIBLE);
             status.setText(r.getString(R.string.device_paused));
             status.setTextColor(ContextCompat.getColor(getContext(), R.color.text_black));
             return convertView;
@@ -70,6 +78,8 @@ public class DevicesAdapter extends ArrayAdapter<Device> {
         if (conn.connected) {
             download.setText(Util.readableTransferRate(getContext(), conn.inBits));
             upload.setText(Util.readableTransferRate(getContext(), conn.outBits));
+            rateInOutView.setVisibility(VISIBLE);
+            status.setVisibility(VISIBLE);
             if (conn.completion == 100) {
                 status.setText(r.getString(R.string.device_up_to_date));
                 status.setTextColor(ContextCompat.getColor(getContext(), R.color.text_green));
@@ -81,8 +91,8 @@ public class DevicesAdapter extends ArrayAdapter<Device> {
         }
 
         // !conn.connected
-        download.setText(Util.readableTransferRate(getContext(), 0));
+        rateInOutView.setVisibility(GONE);
-        upload.setText(Util.readableTransferRate(getContext(), 0));
+        status.setVisibility(VISIBLE);
         status.setText(r.getString(R.string.device_disconnected));
         status.setTextColor(ContextCompat.getColor(getContext(), R.color.text_red));
         return convertView;
@@ -91,14 +101,20 @@ public class DevicesAdapter extends ArrayAdapter<Device> {
     /**
      * Requests new connection info for all devices visible in listView.
      */
-    public void updateConnections(RestApi api) {
+    public void updateDeviceStatus(RestApi restApi) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
+            // Syncthing is not running. Clear last state.
+            mConnections = null;
+            return;
+        }
         for (int i = 0; i < getCount(); i++) {
-            api.getConnections(this::onReceiveConnections);
+            restApi.getConnections(this::onReceiveConnections);
         }
     }
 
     private void onReceiveConnections(Connections connections) {
         mConnections = connections;
+        // This will invoke "getView" for all elements.
         notifyDataSetChanged();
     }
 }

app/src/main/java/com/nutomic/syncthingandroid/views/FoldersAdapter.java

@@ -62,6 +62,20 @@ public class FoldersAdapter extends ArrayAdapter<Folder> {
             mContext.startService(intent);
         });
         binding.openFolder.setOnClickListener(view -> { FileUtils.openFolder(mContext, folder.path); } );
+
+        // Update folder icon.
+        int drawableId = R.drawable.ic_folder_black_24dp_active;
+        switch (folder.type) {
+            case Constants.FOLDER_TYPE_RECEIVE_ONLY:
+                drawableId = R.drawable.ic_folder_receive_only;
+                break;
+            case Constants.FOLDER_TYPE_SEND_ONLY:
+                drawableId = R.drawable.ic_folder_send_only;
+                break;
+            default:
+        }
+        binding.openFolder.setImageResource(drawableId);
+
         updateFolderStatusView(binding, folder);
         return binding.getRoot();
     }
@@ -72,6 +86,7 @@ public class FoldersAdapter extends ArrayAdapter<Folder> {
             binding.items.setVisibility(GONE);
             binding.override.setVisibility(GONE);
             binding.size.setVisibility(GONE);
+            binding.state.setVisibility(GONE);
             setTextOrHide(binding.invalid, folder.invalid);
             return;
         }
@@ -80,6 +95,7 @@ public class FoldersAdapter extends ArrayAdapter<Folder> {
         boolean outOfSync = folderStatus.state.equals("idle") && neededItems > 0;
         boolean overrideButtonVisible = folder.type.equals(Constants.FOLDER_TYPE_SEND_ONLY) && outOfSync;
         binding.override.setVisibility(overrideButtonVisible ? VISIBLE : GONE);
+        binding.state.setVisibility(VISIBLE);
         if (outOfSync) {
             binding.state.setText(mContext.getString(R.string.status_outofsync));
             binding.state.setTextColor(ContextCompat.getColor(mContext, R.color.text_red));
@@ -143,8 +159,9 @@ public class FoldersAdapter extends ArrayAdapter<Folder> {
      * Requests updated folder status from the api for all visible items.
      */
     public void updateFolderStatus(RestApi restApi) {
-        if (restApi == null) {
+        if (restApi == null || !restApi.isConfigLoaded()) {
-            Log.e(TAG, "updateFolderStatus: restApi == null");
+            // Syncthing is not running. Clear last state.
+            mLocalFolderStatuses.clear();
             return;
         }
 
@@ -158,6 +175,7 @@ public class FoldersAdapter extends ArrayAdapter<Folder> {
 
     private void onReceiveFolderStatus(String folderId, FolderStatus folderStatus) {
         mLocalFolderStatuses.put(folderId, folderStatus);
+        // This will invoke "getView" for all elements.
         notifyDataSetChanged();
     }
 

app/src/main/play/en-GB/whatsnew

@@ -2,10 +2,10 @@ Maintenance
 * Updated syncthing core to v0.14.54
 * Fallback to http if https tls 1.2 is unavailable on Android 4.x
 Enhancements
+* UI can be used to configure even when syncthing is not running [NEW]
 * Added "Recent changes" UI, click files to open [NEW]
 * Specify sync conditions differently for each folder, device [NEW]
 * Added offline 'tips & tricks' content [NEW]
-* UI explains why syncthing is running (or not)
 Fixes
 * Fixed the "battery eater"
 * Android 8 and 9 support

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

@@ -1,66 +1,107 @@
 <?xml version="1.0" encoding="utf-8"?>
 
-<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<layout xmlns:android="http://schemas.android.com/apk/res/android">
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content"
-    android:paddingBottom="8dp"
-    android:paddingLeft="@dimen/abc_action_bar_content_inset_material"
-    android:paddingRight="@dimen/abc_action_bar_content_inset_material"
-    android:paddingTop="8dp">
 
-    <TextView
+    <RelativeLayout
-        android:id="@+id/name"
+        xmlns:tools="http://schemas.android.com/tools"
-        android:layout_width="wrap_content"
+        android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_alignParentLeft="true"
+        android:descendantFocusability="blocksDescendants">
-        android:layout_alignParentStart="true"
-        android:layout_toLeftOf="@+id/status"
-        android:layout_toStartOf="@+id/status"
-        android:ellipsize="end"
-        android:lines="1"
-        android:textAppearance="?textAppearanceListItemPrimary" />
 
-    <TextView
+        <RelativeLayout
-        android:id="@+id/status"
+            android:id="@+id/inner"
-        android:layout_width="wrap_content"
+            android:layout_width="match_parent"
-        android:layout_height="wrap_content"
+            android:layout_height="wrap_content"
-        android:layout_alignBottom="@+id/name"
+            android:paddingBottom="8dp"
-        android:layout_alignParentEnd="true"
+            android:paddingLeft="@dimen/abc_action_bar_content_inset_material"
-        android:layout_alignParentRight="true"
+            android:paddingRight="@dimen/abc_action_bar_content_inset_material"
-        android:textAppearance="?textAppearanceListItemSmall" />
+            android:paddingTop="8dp">
 
-    <TextView
+            <TextView
-        android:id="@+id/download_title"
+                android:id="@+id/name"
-        android:layout_width="wrap_content"
+                android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
+                android:layout_height="wrap_content"
-        android:layout_below="@id/name"
+                android:layout_alignParentStart="true"
-        android:text="@string/download_title_colon"
+                android:layout_alignParentLeft="true"
-        android:textAppearance="?textAppearanceListItemSecondary" />
+                android:ellipsize="end"
+                android:lines="1"
+                android:textAppearance="?textAppearanceListItemPrimary" />
 
-    <TextView
+            <RelativeLayout
-        android:id="@+id/download"
+                android:id="@+id/rateInOutContainer"
-        android:layout_width="wrap_content"
+                android:layout_width="match_parent"
-        android:layout_height="wrap_content"
+                android:layout_height="match_parent"
-        android:layout_alignBaseline="@id/download_title"
+                android:layout_below="@+id/name">
-        android:layout_toEndOf="@id/download_title"
-        android:layout_toRightOf="@id/download_title"
-        android:textAppearance="?textAppearanceListItemSecondary" />
 
-    <TextView
+                <TextView
-        android:id="@+id/upload_title"
+                    android:id="@+id/download_title"
-        android:layout_width="wrap_content"
+                    android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
+                    android:layout_height="wrap_content"
-        android:layout_below="@id/download_title"
+                    android:text="@string/download_title_colon"
-        android:text="@string/upload_title_colon"
+                    android:textAppearance="?textAppearanceListItemSecondary" />
-        android:textAppearance="?textAppearanceListItemSecondary" />
 
-    <TextView
+                <TextView
-        android:id="@+id/upload"
+                    android:id="@+id/download"
-        android:layout_width="wrap_content"
+                    android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
+                    android:layout_height="wrap_content"
-        android:layout_alignBaseline="@id/upload_title"
+                    android:layout_alignBaseline="@id/download_title"
-        android:layout_toEndOf="@id/upload_title"
+                    android:layout_toEndOf="@id/download_title"
-        android:layout_toRightOf="@id/upload_title"
+                    android:layout_toRightOf="@id/download_title"
-        android:textAppearance="?textAppearanceListItemSecondary" />
+                    android:textAppearance="?textAppearanceListItemSecondary" />
 
-</RelativeLayout>
+                <TextView
+                    android:id="@+id/upload_title"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_below="@id/download_title"
+                    android:text="@string/upload_title_colon"
+                    android:textAppearance="?textAppearanceListItemSecondary" />
+
+                <TextView
+                    android:id="@+id/upload"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_alignBaseline="@id/upload_title"
+                    android:layout_toEndOf="@id/upload_title"
+                    android:layout_toRightOf="@id/upload_title"
+                    android:textAppearance="?textAppearanceListItemSecondary" />
+
+            </RelativeLayout>
+
+        </RelativeLayout>
+
+        <TextView
+            android:id="@+id/status"
+            android:ellipsize="end"
+            android:gravity="center_vertical"
+            android:layout_alignBottom="@+id/inner"
+            android:layout_alignTop="@+id/inner"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_toStartOf="@+id/open_device"
+            android:layout_toLeftOf="@+id/open_device"
+            android:lines="1"
+            android:textAppearance="?textAppearanceListItemSmall"
+            tools:ignore="RelativeOverlap" />
+
+        <ImageButton
+            android:id="@+id/open_device"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_alignBottom="@+id/inner"
+            android:layout_alignParentEnd="true"
+            android:layout_alignParentRight="true"
+            android:layout_alignTop="@+id/inner"
+            android:background="@null"
+            android:contentDescription="@null"
+            android:paddingBottom="5dp"
+            android:paddingEnd="20dp"
+            android:paddingLeft="25dp"
+            android:paddingRight="20dp"
+            android:paddingStart="30dp"
+            android:paddingTop="5dp"
+            android:src="@drawable/ic_phonelink_black_24dp_active" />
+
+    </RelativeLayout>
+
+</layout>

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

@@ -32,7 +32,6 @@
                 android:id="@+id/state"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-                android:layout_alignBottom="@id/id"
                 android:layout_alignParentEnd="true"
                 android:layout_alignParentRight="true"
                 android:textAppearance="?textAppearanceListItemSmall" />
@@ -41,7 +40,7 @@
                 android:id="@+id/directory"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-                android:layout_below="@id/state"
+                android:layout_below="@id/label"
                 android:ellipsize="end"
                 android:textAppearance="?textAppearanceListItemSecondary" />
 

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

@@ -220,6 +220,9 @@ Bitte melden Sie auftretende Probleme via GitHub.</string>
     <!-- Toast shown when trying to create a folder with an empty ID -->
     <string name="folder_id_required">Die Verzeichnis ID darf nicht leer sein</string>
 
+    <!-- Toast shown when trying to create a folder with an empty label -->
+    <string name="folder_label_required">Die Verzeichnisbezeichnung darf nicht leer sein</string>
+
     <!-- Toast shown when trying to create a folder with an empty path -->
     <string name="folder_path_required">Der Verzeichnispfad darf nicht leer sein</string>
 
@@ -283,6 +286,12 @@ Bitte melden Sie auftretende Probleme via GitHub.</string>
     <!-- Toast shown when trying to create a device with an empty ID -->
     <string name="device_id_required">Die Geräte-ID darf nicht leer sein</string>
 
+    <!-- Toast shown when trying to create a device with an empty ID -->
+    <string name="device_id_invalid">Die Geräte-ID ist nicht im richtigen Format. Bitte versuche es erneut und gebe die richtige ID ein.</string>
+
+    <!-- Toast shown when trying to create a device with an empty name -->
+    <string name="device_name_required">Der Gerätename darf nicht leer sein</string>
+
     <!-- Content description for device ID qr code icon -->
     <string name="scan_qr_code_description">QR Code scannen</string>
 
@@ -416,7 +425,7 @@ Bitte melden Sie auftretende Probleme via GitHub.</string>
         <item>Keine</item>
         <item>Papierkorb</item>
         <item>Einfach</item>
-        <item>Stufenweis</item>
+        <item>Gestaffelt</item>
         <item>Extern</item>
     </string-array>
 

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

@@ -220,6 +220,9 @@ Please report any problems you encounter via Github.</string>
     <!-- Toast shown when trying to create a folder with an empty ID -->
     <string name="folder_id_required">The folder ID must not be empty</string>
 
+    <!-- Toast shown when trying to create a folder with an empty label -->
+    <string name="folder_label_required">The folder label must not be empty</string>
+
     <!-- Toast shown when trying to create a folder with an empty path -->
     <string name="folder_path_required">The folder path must not be empty</string>
 
@@ -283,6 +286,12 @@ Please report any problems you encounter via Github.</string>
     <!-- Toast shown when trying to create a device with an empty ID -->
     <string name="device_id_required">The device ID must not be empty</string>
 
+    <!-- Toast shown when trying to create a device with an empty ID -->
+    <string name="device_id_invalid">The device ID is not formatted correctly. Please retry and enter the correct ID.</string>
+
+    <!-- Toast shown when trying to create a device with an empty name -->
+    <string name="device_name_required">The device name must not be empty</string>
+
     <!-- Content description for device ID qr code icon -->
     <string name="scan_qr_code_description">Scan QR Code</string>