add refresh controller

cyberwow/lib/controller/refresh.dart

@@ -0,0 +1,40 @@
+/*
+
+Copyright 2019 fuwa
+
+This file is part of CyberWOW.
+
+CyberWOW is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+CyberWOW is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with CyberWOW.  If not, see <https://www.gnu.org/licenses/>.
+
+*/
+
+import 'dart:ui';
+import 'dart:async';
+import 'rpc.dart' as rpc;
+
+typedef GetNotificationFunc = AppLifecycleState Function();
+
+Stream<int> targetHeight(GetNotificationFunc getNotification) async* {
+  while (true) {
+    final _appState = getNotification();
+    print('refresh targetHeight: app state: ${_appState}');
+
+    if (_appState == AppLifecycleState.resumed) {
+      final _targetHeight = await rpc.targetHeight();
+      yield _targetHeight
+    }
+
+    await Future.delayed(const Duration(seconds: 2), () => "1");
+  }
+}

cyberwow/lib/state.dart

@@ -30,6 +30,7 @@ import 'package:path_provider/path_provider.dart';
 
 import 'controller/helper.dart';
 import 'controller/rpc.dart' as rpc;
+import 'controller/refresh.dart' as refresh;
 import 'config.dart';
 
 abstract class AppState {
@@ -202,6 +203,7 @@ class SyncedState extends HookedState {
 class ReSyncingState extends HookedState {
   String stdout;
   Stream<String> processOutput;
+  bool synced = false;
 
   ReSyncingState(f, s, this.stdout, this.processOutput) : super (f, s);
 
@@ -213,14 +215,27 @@ class ReSyncingState extends HookedState {
   Future<SyncedState> next() async {
     print("ReSyncing next");
 
-    await for (var line in processOutput) {
-      append(line);
-      print(line);
+    Future<void> printStdout() async {
+      await for (var line in processOutput) {
+        append(line);
+        print(line);
 
-      final _targetHeight = await rpc.targetHeight();
-      if (_targetHeight == 0) break;
+        if (synced) break;
+      }
     }
 
+    Future<void> checkSync() async {
+      await for (var _targetHeight in refresh.targetHeight(getNotification)) {
+        if (_targetHeight == 0) {
+          synced = true;
+          break;
+        }
+      }
+    }
+
+    printStdout();
+    await checkSync();
+
     print('resync: await exit');
     SyncedState _next = SyncedState(setState, getNotification, stdout, processOutput);
     _next.height = await rpc.height();