opt.: dismiss notification if no ssh conn (#592)

lib/core/channel/bg_run.dart

@@ -11,4 +11,8 @@ abstract final class BgRunMC {
   static void startService() {
     _channel.invokeMethod('startService');
   }
+
+  static void stopService() {
+    _channel.invokeMethod('stopService');
+  }
 }

lib/main.dart

@@ -9,7 +9,6 @@ import 'package:flutter_displaymode/flutter_displaymode.dart';
 import 'package:hive_flutter/hive_flutter.dart';
 import 'package:logging/logging.dart';
 import 'package:server_box/app.dart';
-import 'package:server_box/core/channel/bg_run.dart';
 import 'package:server_box/core/sync.dart';
 import 'package:server_box/data/model/app/menu/server_func.dart';
 import 'package:server_box/data/model/app/net_view.dart';
@@ -111,10 +110,6 @@ void _doPlatformRelated() async {
   if (isAndroid) {
     // try switch to highest refresh rate
     FlutterDisplayMode.setHighRefreshRate();
-    if (Stores.setting.bgRun.fetch()) {
-      Loggers.app.info('Start foreground service');
-      BgRunMC.startService();
-    }
   }
 
   final serversCount = Stores.server.box.keys.length;

lib/view/page/ssh/page.dart

@@ -6,6 +6,7 @@ import 'package:fl_lib/fl_lib.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:provider/provider.dart';
+import 'package:server_box/core/channel/bg_run.dart';
 import 'package:server_box/core/extension/context/locale.dart';
 import 'package:server_box/core/utils/ssh_auth.dart';
 import 'package:server_box/core/utils/server.dart';
@@ -70,13 +71,22 @@ class SSHPageState extends State<SSHPage>
   late SSHClient? _client = widget.spi.server?.value.client;
   Timer? _discontinuityTimer;
 
+  /// Used for (de)activate the wake lock and forground service
+  static var _sshConnCount = 0;
+
   @override
   void dispose() {
     super.dispose();
     _virtKeyLongPressTimer?.cancel();
     _terminalController.dispose();
     _discontinuityTimer?.cancel();
-    WakelockPlus.disable();
+
+    if (--_sshConnCount <= 0) {
+      WakelockPlus.disable();
+      if (isAndroid) {
+        BgRunMC.stopService();
+      }
+    }
   }
 
   @override
@@ -85,6 +95,13 @@ class SSHPageState extends State<SSHPage>
     _initStoredCfg();
     _initVirtKeys();
     _setupDiscontinuityTimer();
+
+    if (++_sshConnCount == 1) {
+      WakelockPlus.enable();
+      if (isAndroid) {
+        BgRunMC.startService();
+      }
+    }
   }
 
   @override