Initial commit

lib/materialAppWithIntro.dart

@@ -0,0 +1,81 @@
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'dart:async';
+
+abstract class MaterialAppWithIntro extends StatelessWidget {
+  final String name;
+  final ThemeData theme;
+  final Map<String, WidgetBuilder> routes;
+  final WidgetBuilder introWidget;
+  final WidgetBuilder continueWidget;
+  final String prefsKey;
+
+  MaterialAppWithIntro(this.name, this.theme, this.routes, this.introWidget,
+    this.continueWidget, this.prefsKey);
+
+  @override
+  Widget build(BuildContext context) {
+    return new MaterialApp(
+      home: new MaterialAppWithIntroHome(introWidget, continueWidget, prefsKey),
+      title: name,
+      theme: theme,
+      routes: routes);
+  }
+}
+
+class MaterialAppWithIntroHome extends StatefulWidget {
+  final WidgetBuilder introWidget;
+  final WidgetBuilder continueWidget;
+  final String prefsKey;
+
+  MaterialAppWithIntroHome(this.introWidget, this.continueWidget, this.prefsKey);
+
+  @override
+  _MaterialAppWithIntroState createState() =>
+    _MaterialAppWithIntroState(introWidget, continueWidget, prefsKey);
+}
+
+class _MaterialAppWithIntroState extends State<MaterialAppWithIntroHome> {
+  final WidgetBuilder introWidget;
+  final WidgetBuilder continueWidget;
+  final String prefsKey;
+
+  _MaterialAppWithIntroState(this.introWidget, this.continueWidget, this.prefsKey);
+
+  @override
+  void initState() {
+    super.initState();
+    new Timer(new Duration(milliseconds: 1000), () {
+      checkFirstStart();
+    });
+  }
+
+  // https://stackoverflow.com/questions/50654195/flutter-one-time-intro-screen
+  Future checkFirstStart() async {
+    final String initialWizardKey = prefsKey;
+    SharedPreferences prefs = await SharedPreferences.getInstance();
+    bool showInitialWizard = (prefs.getBool(initialWizardKey) ?? true);
+
+    if (showInitialWizard) {
+      prefs.setBool(initialWizardKey, false);
+      print('Show initial intro at first start');
+      Navigator
+        .of(context)
+        .pushReplacement(new MaterialPageRoute(builder: this.introWidget));
+    } else {
+      print('Don\'t show initial intro ');
+      Navigator
+        .of(context)
+        .pushReplacement(new MaterialPageRoute(builder: this.continueWidget));
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return new Scaffold(
+      body: new Center(
+        child: new CircularProgressIndicator(),// Loading...
+      ),
+    );
+  }
+}