Instead of crashing, display a notification that the service couldn't be started

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBApplication.java

@@ -43,6 +43,7 @@ import android.provider.ContactsContract.PhoneLookup;
 import android.util.Log;
 import android.util.TypedValue;
 
+import androidx.core.app.NotificationCompat;
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 
 import java.io.File;
@@ -86,8 +87,9 @@ import static nodomain.freeyourgadget.gadgetbridge.model.DeviceType.MIBAND;
 import static nodomain.freeyourgadget.gadgetbridge.model.DeviceType.MIBAND2;
 import static nodomain.freeyourgadget.gadgetbridge.model.DeviceType.MIBAND3;
 import static nodomain.freeyourgadget.gadgetbridge.model.DeviceType.fromKey;
-import static nodomain.freeyourgadget.gadgetbridge.util.GB.NOTIFICATION_CHANNEL_ID;
 import static nodomain.freeyourgadget.gadgetbridge.util.GB.NOTIFICATION_CHANNEL_HIGH_PRIORITY_ID;
+import static nodomain.freeyourgadget.gadgetbridge.util.GB.NOTIFICATION_CHANNEL_ID;
+
 /**
  * Main Application class that initializes and provides access to certain things like
  * logging and DB access.
@@ -104,6 +106,9 @@ public class GBApplication extends Application {
     private static final String PREFS_VERSION = "shared_preferences_version";
     //if preferences have to be migrated, increment the following and add the migration logic in migratePrefs below; see http://stackoverflow.com/questions/16397848/how-can-i-migrate-android-preferences-with-a-new-version
     private static final int CURRENT_PREFS_VERSION = 7;
+
+    private static final int ERROR_IN_GADGETBRIDGE_NOTIFICATION = 42;
+
     private static LimitedQueue mIDSenderLookup = new LimitedQueue(16);
     private static Prefs prefs;
     private static GBPrefs gbPrefs;
@@ -208,7 +213,7 @@ public class GBApplication extends Application {
                     notificationManager.createNotificationChannel(channel);
                 }
 
-                NotificationChannel channelHighPr = notificationManager.getNotificationChannel(NOTIFICATION_CHANNEL_HIGH_PRIORITY_ID );
+                NotificationChannel channelHighPr = notificationManager.getNotificationChannel(NOTIFICATION_CHANNEL_HIGH_PRIORITY_ID);
                 if (channelHighPr == null) {
                     channelHighPr = new NotificationChannel(NOTIFICATION_CHANNEL_HIGH_PRIORITY_ID,
                             getString(R.string.notification_channel_high_priority_name),
@@ -219,7 +224,23 @@ public class GBApplication extends Application {
                 bluetoothStateChangeReceiver = new BluetoothStateChangeReceiver();
                 registerReceiver(bluetoothStateChangeReceiver, new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED));
             }
-            startService(new Intent(this, NotificationCollectorMonitorService.class));
+            try {
+                startService(new Intent(this, NotificationCollectorMonitorService.class));
+            } catch (IllegalStateException e) {
+                String message = e.toString();
+                if (message == null) {
+                    message = getString(R.string._unknown_);
+                }
+                notificationManager.notify(ERROR_IN_GADGETBRIDGE_NOTIFICATION,
+                        new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_HIGH_PRIORITY_ID)
+                                .setSmallIcon(R.drawable.gadgetbridge_img)
+                                .setContentTitle(getString(R.string.error_background_service))
+                                .setContentText(getString(R.string.error_background_service_reason_truncated))
+                                .setStyle(new NotificationCompat.BigTextStyle()
+                                        .bigText(getString(R.string.error_background_service_reason) + "\"" + message + "\""))
+                                .setPriority(NotificationCompat.PRIORITY_DEFAULT)
+                                .build());
+            }
         }
     }
 

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

@@ -880,6 +880,9 @@
     <string name="about_additional_contributions">Many thanks to all unlisted contributors for contributing code, support, ideas, motivation, bug reports, money… ✊</string>
     <string name="permission_granting_mandatory">All these permissions are required and instability might occur if not granted</string>
     <string name="error_version_check_extreme_caution">CAUTION: Error when checking version information! You should not continue! Saw version name \"%s\"</string>
+    <string name="error_background_service">Failed to start background service</string>
+    <string name="error_background_service_reason_truncated">Starting the background service failed because…</string>
+    <string name="error_background_service_reason">Starting the background service failed because of an exception. Error: </string>
     <plurals name="widget_alarm_target_hours">
         <item quantity="one">%d hour</item>
         <item quantity="two">%d hours</item>