Modernize the app and fix countless connection stability issues

.github/workflows/android.yml

@@ -14,26 +14,32 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v7
+
     - name: set up JDK 17
-      uses: actions/setup-java@v2
+      uses: actions/setup-java@v5
       with:
         java-version: '17'
-        distribution: 'adopt'
+        distribution: 'temurin'
 
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
-    - name: Build with Gradle
-      run: ./gradlew build
 
-    - name: Archive linter results
-      uses: actions/upload-artifact@v3
-      with:
-        name: lint-result.html
-        path: app/build/reports/lint-results-debug.html
+    - name: Assemble build artifact
+      run: ./gradlew assemble
 
     - name: Archive debug.apk
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v7
       with:
         name: asteroidossync-debug.apk
         path: app/build/outputs/apk/debug/app-debug.apk
+
+    - name: Run checks
+      run: ./gradlew build
+
+    - name: Archive linter results
+      uses: actions/upload-artifact@v7
+      if: always()
+      with:
+        name: lint-result.html
+        path: app/build/reports/lint-results-debug.html

app/build.gradle.kts

@@ -1,15 +1,14 @@
 plugins {
-    id("com.android.application")
+    alias(libs.plugins.android.application)
 }
 
 android {
-    compileSdk = 33
-    buildToolsVersion = "30.0.3"
+    compileSdk = 34
 
     defaultConfig {
         applicationId = "org.asteroidos.sync"
         minSdk = 24
-        targetSdk = 33
+        targetSdk = 34
         versionCode = 29
         versionName = "0.29"
     }
@@ -25,6 +24,7 @@ android {
                 srcDir("src/main/lib/android-ripple-background/library/src/main/java/")
                 srcDir("src/main/lib/material-intro-screen/material-intro-screen/src/main/java/")
                 srcDir("src/main/lib/powerampapi/poweramp_api_lib/src/")
+                srcDir("src/main/lib/easyweather/src/main/java/")
             }
             res {
                 srcDir("src/main/lib/android-ripple-background/library/src/main/res/")
@@ -45,22 +45,19 @@ android {
     namespace = "org.asteroidos.sync"
 }
 
-repositories {
-    mavenCentral()
-    maven("https://maven.google.com")
-    maven("https://jitpack.io")
-}
-
 dependencies {
     implementation(fileTree(mapOf("dir" to "libs", "include" to listOf("*.jar"))))
-    testImplementation("junit:junit:4.13.2")
-    implementation("androidx.appcompat:appcompat:1.6.1")
-    implementation("androidx.legacy:legacy-support-v4:1.0.0")
-    implementation("androidx.cardview:cardview:1.0.0")
-    implementation("com.google.android.material:material:1.9.0")
-    implementation("com.github.MagneFire:EasyWeather:1.3")
-    implementation("com.google.code.gson:gson:2.10.1")
-    implementation("org.osmdroid:osmdroid-android:6.1.16")
-    implementation("no.nordicsemi.android.support.v18:scanner:1.6.0")
-    implementation("no.nordicsemi.android:ble:2.7.2")
+    testImplementation(libs.junit)
+    implementation(libs.androidx.appcompat)
+    implementation(libs.androidx.cardview)
+    implementation(libs.material)
+    // EasyWeather is vendored under src/main/lib/easyweather (see its README);
+    // these are the runtime dependencies it needs, from Maven Central.
+    implementation(libs.retrofit)
+    implementation(libs.retrofit.converter.gson)
+    implementation(libs.okhttp.logging.interceptor)
+    implementation(libs.gson)
+    implementation(libs.osmdroid.android)
+    implementation(libs.nordic.scanner)
+    implementation(libs.nordic.ble)
 }

app/src/main/AndroidManifest.xml

@@ -11,14 +11,14 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
-    <uses-permission android:name="android.permission.ACCESS_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.NEARBY_WIFI_DEVICES" android:usesPermissionFlags="neverForLocation"/>
 
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_CONNECTED_DEVICE" />
     <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"/>
     <uses-permission android:name="android.permission.READ_PHONE_STATE"/>
     <uses-permission android:name="android.permission.READ_CALL_LOG"/>
@@ -87,6 +87,7 @@
             android:name=".services.SynchronizationService"
             android:enabled="true"
             android:exported="false"
+            android:foregroundServiceType="connectedDevice"
             android:label="SynchronizationService" />
 
         <receiver android:name=".services.AutostartService"

app/src/main/java/org/asteroidos/sync/MainActivity.java

@@ -22,6 +22,7 @@
 import android.app.AlertDialog;
 import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
+import android.bluetooth.BluetoothManager;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
@@ -43,6 +44,7 @@
 import android.util.Log;
 import android.view.MenuItem;
 
+import androidx.activity.OnBackPressedCallback;
 import androidx.activity.result.ActivityResultLauncher;
 import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.NonNull;
@@ -89,6 +91,7 @@ public class MainActivity extends AppCompatActivity implements DeviceListFragmen
     public final ParcelUuid asteroidUUID = fromString(AsteroidUUIDS.SERVICE_UUID.toString());
     Messenger mSyncServiceMessenger;
     ActivityResultLauncher<Intent> mLocationEnableActivityLauncher;
+    ActivityResultLauncher<Intent> mBtEnableLauncher;
     LocationManager mLocationManager;
     /* Synchronization service events handling */
     private final ServiceConnection mConnection = new ServiceConnection() {
@@ -116,7 +119,7 @@ public void onScanResult(int callbackType, @NonNull ScanResult result) {
             mListFragment.deviceDiscovered(result.getDevice());
             if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-                    ActivityCompat.requestPermissions(getParent(), new String[]{Manifest.permission.BLUETOOTH_CONNECT}, 225);
+                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.BLUETOOTH_CONNECT}, 225);
                 }
                 return;
             }
@@ -128,6 +131,7 @@ public void onScanResult(int callbackType, @NonNull ScanResult result) {
     private Fragment mPreviousFragment;
     private BluetoothLeScannerCompat mScanner;
     private SharedPreferences mPrefs;
+    private OnBackPressedCallback mBackCallback;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -153,6 +157,17 @@ protected void onCreate(Bundle savedInstanceState) {
                 new ActivityResultContracts.StartActivityForResult(),
                 result -> btEnableAndScan()
         );
+        mBtEnableLauncher = registerForActivityResult(
+                new ActivityResultContracts.StartActivityForResult(),
+                result -> btEnableAndScan()
+        );
+        mBackCallback = new OnBackPressedCallback(true) {
+            @Override
+            public void handleOnBackPressed() {
+                handleBack();
+            }
+        };
+        getOnBackPressedDispatcher().addCallback(this, mBackCallback);
         btEnable();
 
         /* Start and/or attach to the Synchronization Service */
@@ -271,29 +286,32 @@ public void onDisconnectRequested() {
     @Override
     public boolean onOptionsItemSelected(MenuItem menuItem) {
         if (menuItem.getItemId() == android.R.id.home)
-            onBackPressed();
+            getOnBackPressedDispatcher().onBackPressed();
 
         return (super.onOptionsItemSelected(menuItem));
     }
 
-    @Override
-    public void onBackPressed() {
+    private void handleBack() {
         FragmentManager fm = getSupportFragmentManager();
         if (fm.getBackStackEntryCount() > 0) {
             fm.popBackStack();
             setTitle(mPrefs.getString(PREFS_DEFAULT_LOC_NAME, ""));
             ActionBar ab = getSupportActionBar();
             if (ab != null)
                 ab.setDisplayHomeAsUpEnabled(false);
-        } else
-            finish();
-        try {
-            mDetailFragment = (DeviceDetailFragment) mPreviousFragment;
-        } catch (ClassCastException ignored1) {
             try {
-                mListFragment = (DeviceListFragment) mPreviousFragment;
-            } catch (ClassCastException ignored2) {
+                mDetailFragment = (DeviceDetailFragment) mPreviousFragment;
+            } catch (ClassCastException ignored1) {
+                try {
+                    mListFragment = (DeviceListFragment) mPreviousFragment;
+                } catch (ClassCastException ignored2) {
+                }
             }
+        } else {
+            // Nothing left on the back stack: hand control back to the platform
+            // default (finishing the activity) via the dispatcher.
+            mBackCallback.setEnabled(false);
+            getOnBackPressedDispatcher().onBackPressed();
         }
     }
 
@@ -378,16 +396,19 @@ public void onScanRequested() {
     }
 
     private void btEnable() {
-        BluetoothAdapter mBtAdapter;
-        mBtAdapter = BluetoothAdapter.getDefaultAdapter();
-        if (!mBtAdapter.isEnabled()) {
-            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
-                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-                    ActivityCompat.requestPermissions(getParent(), new String[]{Manifest.permission.BLUETOOTH_CONNECT}, 225);
-                }
+        BluetoothManager btManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
+        BluetoothAdapter btAdapter = btManager != null ? btManager.getAdapter() : null;
+        if (btAdapter == null) return; // device has no Bluetooth
+        if (!btAdapter.isEnabled()) {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S
+                    && ActivityCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
+                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH_CONNECT}, 225);
                 return;
             }
-            mBtAdapter.enable();
+            // BluetoothAdapter.enable() is deprecated and a no-op since Android
+            // 13 (apps can no longer silently toggle Bluetooth), so ask the user
+            // to enable it instead.
+            mBtEnableLauncher.launch(new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE));
         }
     }
 
@@ -445,9 +466,10 @@ public void onConfigurationChanged(@NonNull Configuration newConfig) {
                 break;
         }
 
-        finish();
-        overridePendingTransition(0, 0);
-        startActivity(getIntent());
+        // Recreate the activity to apply the new theme. This is the modern
+        // equivalent of the previous finish()/startActivity() restart and keeps
+        // the task and back stack intact instead of tearing them down.
+        recreate();
     }
 
     static private class SynchronizationHandler extends Handler {

app/src/main/java/org/asteroidos/sync/asteroid/AsteroidBleManager.java

@@ -53,6 +53,14 @@ public class AsteroidBleManager extends BleManager {
     // a smaller chunk size has no effect other than splitting into more writes.
     private static final int MAX_ATTRIBUTE_LENGTH = 512;
 
+    // Request the largest ATT_MTU the BLE spec allows (517 bytes) at connection
+    // time. A bigger MTU means fewer, larger GATT writes and notifications, so
+    // syncs (notifications, screenshots, weather) transfer faster. This is only
+    // safe because CAPPED_SPLITTER above clamps every write to the 512-byte
+    // attribute limit no matter what MTU the system negotiates; the peer always
+    // falls back to a smaller MTU if it can't support the maximum.
+    private static final int GATT_MAX_MTU = 517;
+
     private static final DataSplitter CAPPED_SPLITTER = (message, index, maxLength) -> {
         final int size = Math.min(maxLength, MAX_ATTRIBUTE_LENGTH);
         final int offset = index * size;
@@ -80,8 +88,14 @@ public AsteroidBleManager(@NonNull final Context context, SynchronizationService
     }
 
     public final void send(UUID characteristic, byte[] data) {
-        writeCharacteristic(sendingCharacteristics.get(characteristic), data,
-                Objects.requireNonNull(sendingCharacteristics.get(characteristic)).getWriteType()).split(CAPPED_SPLITTER).enqueue();
+        if (sendingCharacteristics == null)
+            return;
+        BluetoothGattCharacteristic gattCharacteristic = sendingCharacteristics.get(characteristic);
+        if (gattCharacteristic == null) {
+            Log.w(TAG, "No writable characteristic for " + characteristic + "; dropping write");
+            return;
+        }
+        writeCharacteristic(gattCharacteristic, data, gattCharacteristic.getWriteType()).split(CAPPED_SPLITTER).enqueue();
     }
 
     @NonNull
@@ -138,6 +152,13 @@ public final boolean isRequiredServiceSupported(@NonNull final BluetoothGatt gat
 
             for (IConnectivityService service : mSynchronizationService.getServices().values()) {
                 BluetoothGattService bluetoothGattService = gatt.getService(service.getServiceUUID());
+                // A flaky reconnect can return a partial GATT table. Skipping a
+                // missing service avoids a NullPointerException here that would
+                // abort the whole connection and trap us in a retry loop.
+                if (bluetoothGattService == null) {
+                    Log.w(TAG, "Service not exposed by watch, skipping: " + service.getServiceUUID());
+                    continue;
+                }
                 List<UUID> sendUuids = new ArrayList<>();
                 service.getCharacteristicUUIDs().forEach((uuid, direction) -> {
                     if (direction == IConnectivityService.Direction.TO_WATCH)
@@ -147,11 +168,13 @@ public final boolean isRequiredServiceSupported(@NonNull final BluetoothGatt gat
 
                 for (UUID uuid : sendUuids) {
                     BluetoothGattCharacteristic characteristic = bluetoothGattService.getCharacteristic(uuid);
-                    sendingCharacteristics.put(uuid, characteristic);
-                    bluetoothGattService.addCharacteristic(characteristic);
+                    if (characteristic != null)
+                        sendingCharacteristics.put(uuid, characteristic);
                 }
                 recvCallbacks.forEach((characteristic, callback) -> {
                     BluetoothGattCharacteristic characteristic1 = bluetoothGattService.getCharacteristic(characteristic);
+                    if (characteristic1 == null)
+                        return;
                     removeNotificationCallback(characteristic1);
                     setNotificationCallback(characteristic1).with((device, data) -> callback.call(data.getValue()));
                     enableNotifications(characteristic1).enqueue();
@@ -164,7 +187,7 @@ public final boolean isRequiredServiceSupported(@NonNull final BluetoothGatt gat
         @Override
         protected final void initialize() {
             beginAtomicRequestQueue()
-                    .add(requestMtu(256) // Remember, GATT needs 3 bytes extra. This will allow packet size of 244 bytes.
+                    .add(requestMtu(GATT_MAX_MTU)
                             .with((device, mtu) -> log(Log.INFO, "MTU set to " + mtu))
                             .fail((device, status) -> log(Log.WARN, "Requested MTU not supported: " + status)))
                     .done(device -> log(Log.INFO, "Target initialized"))

app/src/main/java/org/asteroidos/sync/connectivity/MediaService.java

@@ -76,7 +76,7 @@ public MediaService(Context ctx, IAsteroidDevice device) {
         mDevice = device;
         mCtx = ctx;
         device.registerCallback(AsteroidUUIDS.MEDIA_COMMANDS_CHAR, (data) -> {
-            if (data == null) return;
+            if (data == null || data.length < 1) return;
             if (mMediaController != null) {
                 boolean isPoweramp = mSettings.getString(PREFS_MEDIA_CONTROLLER_PACKAGE, PREFS_MEDIA_CONTROLLER_PACKAGE_DEFAULT)
                         .equals(PowerampAPI.PACKAGE_NAME);
@@ -115,7 +115,7 @@ public MediaService(Context ctx, IAsteroidDevice device) {
                         }
                         break;
                     case MEDIA_COMMAND_VOLUME:
-                        if (mMediaController.getPlaybackInfo() != null) {
+                        if (data.length >= 2 && mMediaController.getPlaybackInfo() != null) {
                             if (data[1] != mVolume) {
                                 int delta = Math.abs(mVolume - data[1]);
                                 int deviceDelta = 100 / mMediaController.getPlaybackInfo().getMaxVolume();
@@ -200,15 +200,16 @@ private void sendVolume(int volume) {
         mDevice.send(AsteroidUUIDS.MEDIA_VOLUME_CHAR, data, MediaService.this);
     }
 
-    private final ContentObserver mVolumeChangeObserver = new ContentObserver(new Handler()) {
+    private final ContentObserver mVolumeChangeObserver = new ContentObserver(new Handler(Looper.getMainLooper())) {
         // The last value of volume send to the watch.
         private int reportedVolume;
 
         @Override
         public void onChange(boolean selfChange) {
             super.onChange(selfChange);
-            if (mMediaController != null && mMediaController.getPlaybackInfo() != null) {
-                int vol = (100 * mMediaController.getPlaybackInfo().getCurrentVolume()) / mMediaController.getPlaybackInfo().getMaxVolume();
+            MediaController.PlaybackInfo info = mMediaController != null ? mMediaController.getPlaybackInfo() : null;
+            if (info != null && info.getMaxVolume() > 0) {
+                int vol = (100 * info.getCurrentVolume()) / info.getMaxVolume();
 
                 if (reportedVolume != vol) {
                     reportedVolume = vol;
@@ -269,8 +270,12 @@ public void onMetadataChanged(MediaMetadata metadata) {
                         getTextAsBytes(metadata, MediaMetadata.METADATA_KEY_TITLE),
                         MediaService.this);
 
-                mVolume = (100 * mMediaController.getPlaybackInfo().getCurrentVolume()) / mMediaController.getPlaybackInfo().getMaxVolume();
-                sendVolume(mVolume);
+                MediaController controller = mMediaController;
+                MediaController.PlaybackInfo info = controller != null ? controller.getPlaybackInfo() : null;
+                if (info != null && info.getMaxVolume() > 0) {
+                    mVolume = (100 * info.getCurrentVolume()) / info.getMaxVolume();
+                    sendVolume(mVolume);
+                }
             }
         }