Added code in lib/main.dart from prototype

Signed-off-by: Andreas Fahrecker <AndreasFahrecker@gmail.com>

lib/main.dart

@@ -1,4 +1,7 @@
 import 'package:flutter/material.dart';
+import 'package:percent_indicator/circular_percent_indicator.dart';
+import 'package:percent_indicator/linear_percent_indicator.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 void main() {
   runApp(MyApp());
@@ -9,24 +12,12 @@ class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'Time Progress Calculator',
       theme: ThemeData(
-        // This is the theme of your application.
-        //
-        // Try running your application with "flutter run". You'll see the
-        // application has a blue toolbar. Then, without quitting the app, try
-        // changing the primarySwatch below to Colors.green and then invoke
-        // "hot reload" (press "r" in the console where you ran "flutter run",
-        // or simply save your changes to "hot reload" in a Flutter IDE).
-        // Notice that the counter didn't reset back to zero; the application
-        // is not restarted.
         primarySwatch: Colors.blue,
-        // This makes the visual density adapt to the platform that you run
-        // the app on. For desktop platforms, the controls will be smaller and
-        // closer together (more dense) than on mobile platforms.
         visualDensity: VisualDensity.adaptivePlatformDensity,
       ),
-      home: MyHomePage(title: 'Flutter Demo Home Page'),
+      home: MyHomePage(title: 'Time Progress Calculator'),
     );
   }
 }
@@ -34,15 +25,6 @@ class MyApp extends StatelessWidget {
 class MyHomePage extends StatefulWidget {
   MyHomePage({Key key, this.title}) : super(key: key);
 
-  // This widget is the home page of your application. It is stateful, meaning
-  // that it has a State object (defined below) that contains fields that affect
-  // how it looks.
-
-  // This class is the configuration for the state. It holds the values (in this
-  // case the title) provided by the parent (in this case the App widget) and
-  // used by the build method of the State. Fields in a Widget subclass are
-  // always marked "final".
-
   final String title;
 
   @override
@@ -50,68 +32,172 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
+  final String _startDateKey = "startDate";
+  final String _endDateKey = "endDate";
+  DateTime startDate = DateTime(2000);
+  DateTime endDate = DateTime(2100);
 
-  void _incrementCounter() {
+  void _retrieveDates() async {
+    final SharedPreferences prefs = await SharedPreferences.getInstance();
     setState(() {
-      // This call to setState tells the Flutter framework that something has
+      startDate = DateTime.fromMillisecondsSinceEpoch(
-      // changed in this State, which causes it to rerun the build method below
+          prefs.getInt(_startDateKey) ?? DateTime(2000).millisecondsSinceEpoch);
-      // so that the display can reflect the updated values. If we changed
+      endDate = DateTime.fromMillisecondsSinceEpoch(
-      // _counter without calling setState(), then the build method would not be
+          prefs.getInt(_endDateKey) ?? DateTime(2100).millisecondsSinceEpoch);
-      // called again, and so nothing would appear to happen.
-      _counter++;
     });
   }
 
+  void _selectStartDate(BuildContext context) async {
+    final DateTime picked = await showDatePicker(
+        context: context,
+        initialDate: startDate,
+        firstDate: DateTime(2000),
+        lastDate: DateTime(2100));
+    if (picked != null && picked != startDate) {
+      final SharedPreferences prefs = await SharedPreferences.getInstance();
+      prefs.setInt(_startDateKey, picked.millisecondsSinceEpoch);
+      setState(() {
+        startDate = picked;
+      });
+    }
+  }
+
+  void _selectEndDate(BuildContext context) async {
+    final DateTime picked = await showDatePicker(
+        context: context,
+        initialDate: endDate,
+        firstDate: DateTime(2000),
+        lastDate: DateTime(2100));
+    if (picked != null && picked != endDate) {
+      final SharedPreferences prefs = await SharedPreferences.getInstance();
+      prefs.setInt(_endDateKey, picked.millisecondsSinceEpoch);
+      setState(() {
+        endDate = picked;
+      });
+    }
+  }
+
+  int _getAmountOfDaysDone() {
+    return DateTime.now().difference(startDate).inDays;
+  }
+
+  int _getAmountOfDaysLeft() {
+    return endDate.difference(DateTime.now()).inDays;
+  }
+
+  int _getAmountOfAllDays() {
+    return endDate.difference(startDate).inDays;
+  }
+
+  double _getPercent() {
+    final int wholeDuration = _getAmountOfAllDays();
+    final int currentDuration = _getAmountOfDaysDone();
+    final double onePercent = wholeDuration / 100;
+    return currentDuration / onePercent / 100;
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    _retrieveDates();
+  }
+
   @override
   Widget build(BuildContext context) {
-    // This method is rerun every time setState is called, for instance as done
-    // by the _incrementCounter method above.
-    //
-    // The Flutter framework has been optimized to make rerunning build methods
-    // fast, so that you can just rebuild anything that needs updating rather
-    // than having to individually change instances of widgets.
     return Scaffold(
       appBar: AppBar(
-        // Here we take the value from the MyHomePage object that was created by
-        // the App.build method, and use it to set our appbar title.
         title: Text(widget.title),
       ),
-      body: Center(
+      body: Container(
-        // Center is a layout widget. It takes a single child and positions it
+        margin: const EdgeInsets.all(5.0),
-        // in the middle of the parent.
         child: Column(
-          // Column is also a layout widget. It takes a list of children and
-          // arranges them vertically. By default, it sizes itself to fit its
-          // children horizontally, and tries to be as tall as its parent.
-          //
-          // Invoke "debug painting" (press "p" in the console, choose the
-          // "Toggle Debug Paint" action from the Flutter Inspector in Android
-          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
-          // to see the wireframe for each widget.
-          //
-          // Column has various properties to control how it sizes itself and
-          // how it positions its children. Here we use mainAxisAlignment to
-          // center the children vertically; the main axis here is the vertical
-          // axis because Columns are vertical (the cross axis would be
-          // horizontal).
           mainAxisAlignment: MainAxisAlignment.center,
           children: <Widget>[
-            Text(
+            Expanded(
-              'You have pushed the button this many times:',
+              flex: 1,
+              child: Row(
+                children: <Widget>[
+                  Expanded(
+                    flex: 2,
+                    child: Text(
+                      "Start Date:",
+                      textAlign: TextAlign.right,
+                    ),
+                  ),
+                  Expanded(
+                    flex: 2,
+                    child: Text("${startDate.toLocal()}".split(" ")[0]),
+                  ),
+                  Expanded(
+                    flex: 2,
+                    child: RaisedButton(
+                      onPressed: () => _selectStartDate(context),
+                      child: Text("Change"),
+                      color: Colors.lightBlueAccent,
+                    ),
+                  ),
+                  Spacer(flex: 1)
+                ],
+              ),
             ),
-            Text(
+            Expanded(
-              '$_counter',
+              flex: 1,
-              style: Theme.of(context).textTheme.headline4,
+              child: Row(
+                children: <Widget>[
+                  Expanded(
+                    flex: 2,
+                    child: Text(
+                      "End Date:",
+                      textAlign: TextAlign.right,
+                    ),
+                  ),
+                  Expanded(
+                    flex: 2,
+                    child: Text("${endDate.toLocal()}".split(" ")[0]),
+                  ),
+                  Expanded(
+                    flex: 2,
+                    child: RaisedButton(
+                      onPressed: () => _selectEndDate(context),
+                      child: Text("Change"),
+                      color: Colors.lightBlueAccent,
+                    ),
+                  ),
+                  Spacer(flex: 1)
+                ],
+              ),
+            ),
+            Expanded(
+              flex: 5,
+              child: CircularPercentIndicator(
+                radius: 100,
+                lineWidth: 10,
+                percent: _getPercent(),
+                progressColor: Colors.green,
+                backgroundColor: Colors.red,
+                center: Text("${(_getPercent() * 100).floor()} %"),
+              ),
+            ),
+            Expanded(
+              flex: 1,
+              child: LinearPercentIndicator(
+                padding: EdgeInsets.symmetric(horizontal: 15.0),
+                percent: _getPercent(),
+                leading: Text("${_getAmountOfDaysDone()} Days"),
+                center: Text("${(_getPercent() * 100).floor()} %"),
+                trailing: Text("${_getAmountOfDaysLeft()} Days"),
+                progressColor: Colors.green,
+                backgroundColor: Colors.red,
+                lineHeight: 25,
+              ),
+            ),
+            Expanded(
+              flex: 1,
+              child: Text("${_getAmountOfAllDays()} Days"),
             ),
           ],
         ),
       ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: Icon(Icons.add),
-      ), // This trailing comma makes auto-formatting nicer for build methods.
     );
   }
 }