monitor app lifecycle state

cyberwow/lib/controller/rpc.dart

@@ -59,6 +59,7 @@ Future<http.Response> rpc(String method) async {
 }
 
 Future<http.Response> syncInfo() async {
+  print('rpc sync_info');
   return rpc('sync_info');
 }
 

cyberwow/lib/main.dart

@@ -60,12 +60,25 @@ class MyHomePage extends StatefulWidget {
   _MyHomePageState createState() => _MyHomePageState();
 }
 
-class _MyHomePageState extends State<MyHomePage>
+class _MyHomePageState extends State<MyHomePage> with WidgetsBindingObserver
 {
   int _counter = 0;
   // AppState _state = LoadingState("init...");
 
   AppState _state;
+  AppLifecycleState _notification = AppLifecycleState.resumed;
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    // print('app cycle: ${state}');
+    setState(() { _notification = state; });
+  }
+
+  @override
+  void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
+    super.dispose();
+  }
 
   void _setState(AppState newState) {
     setState
@@ -74,6 +87,10 @@ class _MyHomePageState extends State<MyHomePage>
     );
   }
 
+  AppLifecycleState _getNotification() {
+    return _notification;
+  }
+
   AppState _getState() {
     return _state;
   }
@@ -117,9 +134,11 @@ class _MyHomePageState extends State<MyHomePage>
     super.initState();
     print("MyHomePageState initState");
 
+    WidgetsBinding.instance.addObserver(this);
+
     SystemChrome.setEnabledSystemUIOverlays([SystemUiOverlay.bottom]);
 
-    BlankState _blankState = BlankState(_setState);
+    BlankState _blankState = BlankState(_setState, _getNotification);
     _state = _blankState;
 
     buildStateMachine(_blankState);

cyberwow/lib/state.dart

@@ -62,17 +62,19 @@ abstract class AppState {
 }
 
 typedef SetStateFunc = void Function(AppState);
+typedef GetNotificationFunc = AppLifecycleState Function();
 
 class HookedState extends AppState {
   final SetStateFunc setState;
-  HookedState(this.setState);
+  final GetNotificationFunc getNotification;
+  HookedState(this.setState, this.getNotification);
 }
 
 class BlankState extends HookedState {
-  BlankState(f) : super (f);
+  BlankState(f, s) : super (f, s);
 
   Future<LoadingState> next(String status) async {
-    LoadingState _next = LoadingState(setState, status);
+    LoadingState _next = LoadingState(setState, getNotification, status);
 
     setState(_next);
     return _next;
@@ -83,7 +85,7 @@ class LoadingState extends HookedState {
   String banner;
   String status = '';
 
-  LoadingState(f, this.banner) : super (f);
+  LoadingState(f, s, this.banner) : super (f, s);
 
   void append(String msg) {
     this.status += msg;
@@ -123,7 +125,7 @@ class LoadingState extends HookedState {
       await Future.wait([load(), showBanner()]);
     }
 
-    SyncingState _next = SyncingState(setState, status);
+    SyncingState _next = SyncingState(setState, getNotification, status);
     setState(_next);
     return _next;
   }
@@ -132,7 +134,7 @@ class LoadingState extends HookedState {
 class SyncingState extends HookedState {
   String stdout;
 
-  SyncingState(f, this.stdout) : super (f);
+  SyncingState(f, s, this.stdout) : super (f, s);
 
   void append(String msg) {
     this.stdout += msg;
@@ -148,12 +150,14 @@ class SyncingState extends HookedState {
 
       final _targetHeight = await rpc.targetHeight();
       final _height = await rpc.height();
+      print('syncing: target height ${_targetHeight}');
+      print('syncing: height ${_height}');
 
       if (_targetHeight == 0 && _height > minimumHeight) break;
     }
 
 
-    SyncedState _next = SyncedState(setState, stdout, processOutput);
+    SyncedState _next = SyncedState(setState, getNotification, stdout, processOutput);
     _next.height = await rpc.height();
     setState(_next);
     return _next;
@@ -165,23 +169,24 @@ class SyncedState extends HookedState {
   int height;
   Stream<String> processOutput;
 
-  SyncedState(f, this.stdout, this.processOutput) : super (f);
+  SyncedState(f, s, this.stdout, this.processOutput) : super (f, s);
 
   Future<ReSyncingState> next() async {
     print("Synced next");
 
     while (true) {
-      final _targetHeight = await rpc.targetHeight();
-      if (_targetHeight > 0) break;
-      height = await rpc.height();
+      if (getNotification() == AppLifecycleState.resumed) {
+        final _targetHeight = await rpc.targetHeight();
+        if (_targetHeight > 0) break;
+        height = await rpc.height();
+      }
 
       await Future.delayed(const Duration(seconds: 2), () => "1");
     }
 
     // print('synced: loop exit');
 
-
-    ReSyncingState _next = ReSyncingState(setState, stdout, processOutput);
+    ReSyncingState _next = ReSyncingState(setState, getNotification, stdout, processOutput);
     setState(_next);
     return _next;
   }
@@ -192,7 +197,7 @@ class ReSyncingState extends HookedState {
   String stdout;
   Stream<String> processOutput;
 
-  ReSyncingState(f, this.stdout, this.processOutput) : super (f);
+  ReSyncingState(f, s, this.stdout, this.processOutput) : super (f, s);
 
   void append(String msg) {
     this.stdout += msg;
@@ -212,7 +217,7 @@ class ReSyncingState extends HookedState {
     }
 
     print('resync: await exit');
-    SyncedState _next = SyncedState(setState, stdout, processOutput);
+    SyncedState _next = SyncedState(setState, getNotification, stdout, processOutput);
     _next.height = await rpc.height();
     setState(_next);
     return _next;