migrated to latest flutter version and android studio

android/app/build.gradle

@@ -25,7 +25,7 @@ apply plugin: 'com.android.application'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 27
+    compileSdkVersion 28
 
     lintOptions {
         disable 'InvalidPackage'
@@ -35,7 +35,7 @@ android {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.example.groceryshopflutter"
         minSdkVersion 16
-        targetSdkVersion 27
+        targetSdkVersion 29
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

android/app/src/main/AndroidManifest.xml

@@ -5,34 +5,33 @@
          flutter needs it to communicate with the running application
          to allow setting breakpoints, to provide hot reload, etc.
     -->
-    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.INTERNET" />
 
     <!-- io.flutter.app.FlutterApplication is an android.app.Application that
          calls FlutterMain.startInitialization(this); in its onCreate method.
          In most cases you can leave this as-is, but you if you want to provide
          additional functionality it is fine to subclass or reimplement
          FlutterApplication and put your custom class here. -->
     <application
-        android:name="io.flutter.app.FlutterApplication"
-        android:label="grocery_shop_flutter"
-        android:icon="@mipmap/ic_launcher">
+        android:icon="@mipmap/ic_launcher"
+        android:label="grocery_shop_flutter">
         <activity
-            android:name=".MainActivity"
-            android:launchMode="singleTop"
-            android:theme="@style/LaunchTheme"
+            android:name="io.flutter.embedding.android.FlutterActivity"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density"
             android:hardwareAccelerated="true"
+            android:launchMode="singleTop"
+            android:theme="@style/LaunchTheme"
             android:windowSoftInputMode="adjustResize">
             <!-- This keeps the window background of the activity showing
                  until Flutter renders its first frame. It can be removed if
                  there is no splash screen (such as the default splash screen
                  defined in @style/LaunchTheme). -->
             <meta-data
-                android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
-                android:value="true" />
+                android:name="flutterEmbedding"
+                android:value="2" />
             <intent-filter>
-                <action android:name="android.intent.action.MAIN"/>
-                <category android:name="android.intent.category.LAUNCHER"/>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
     </application>

android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java

@@ -1,23 +1,17 @@
 package io.flutter.plugins;
 
-import io.flutter.plugin.common.PluginRegistry;
+import androidx.annotation.Keep;
+import androidx.annotation.NonNull;
+
+import io.flutter.embedding.engine.FlutterEngine;
 
 /**
  * Generated file. Do not edit.
+ * This file is generated by the Flutter tool based on the
+ * plugins that support the Android platform.
  */
+@Keep
 public final class GeneratedPluginRegistrant {
-  public static void registerWith(PluginRegistry registry) {
-    if (alreadyRegisteredWith(registry)) {
-      return;
-    }
-  }
-
-  private static boolean alreadyRegisteredWith(PluginRegistry registry) {
-    final String key = GeneratedPluginRegistrant.class.getCanonicalName();
-    if (registry.hasPlugin(key)) {
-      return true;
-    }
-    registry.registrarFor(key);
-    return false;
+  public static void registerWith(@NonNull FlutterEngine flutterEngine) {
   }
 }

android/build.gradle

@@ -5,7 +5,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
+        classpath 'com.android.tools.build:gradle:3.5.0'
     }
 }
 

android/gradle/wrapper/gradle-wrapper.properties

@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-bin.zip

android/local.properties

@@ -1,5 +1,5 @@
-sdk.dir=C:\\Users\\willn\\AppData\\Local\\Android\\sdk
-flutter.sdk=C:\\src\\flutter
+sdk.dir=D:\\sdk
+flutter.sdk=D:\\flutter-sdk
 flutter.versionName=1.0.0
 flutter.versionCode=1
 flutter.buildMode=debug

lib/bloc/CartBloc.dart

@@ -1,10 +1,9 @@
-import 'package:rxdart/rxdart.dart';
-import 'package:grocery_shop_flutter/models/Product.dart';
-import 'package:grocery_shop_flutter/models/Order.dart';
 import 'package:grocery_shop_flutter/models/Cart.dart';
+import 'package:grocery_shop_flutter/models/Order.dart';
+import 'package:grocery_shop_flutter/models/Product.dart';
+import 'package:rxdart/rxdart.dart';
 
-class CartBloc{
-
+class CartBloc {
   static int _orderId = 0;
   static CartBloc _cartBloc;
   Cart _currentCart;
@@ -13,16 +12,15 @@ class CartBloc{
   PublishSubject<Order> _publishSubjectOrder;
 
   factory CartBloc(){
-    if(_cartBloc == null)
-      _cartBloc = new CartBloc._();
+    if (_cartBloc == null) _cartBloc = CartBloc._();
 
     return _cartBloc;
   }
 
-  CartBloc._(){
-    _currentCart = new Cart();
-    _publishSubjectCart = new PublishSubject<Cart>();
-    _publishSubjectOrder = new PublishSubject<Order>();
+  CartBloc._() {
+    _currentCart = Cart();
+    _publishSubjectCart = PublishSubject<Cart>();
+    _publishSubjectOrder = PublishSubject<Order>();
   }
 
   Observable<Cart> get observableCart => _publishSubjectCart.stream;
@@ -37,7 +35,7 @@ class CartBloc{
   }
 
   void addOrderToCart(Product product, int quantity){
-    _lastOrder = new Order(product, quantity, _orderId++);
+    _lastOrder = Order(product, quantity, _orderId++);
     _currentCart.addOrder(_lastOrder);
     _updateLastOrder();
     _updateCart();

lib/components/CartManager.dart

@@ -1,65 +1,106 @@
 import 'package:flutter/material.dart';
-import 'package:grocery_shop_flutter/models/Cart.dart';
 import 'package:grocery_shop_flutter/bloc/CartBloc.dart';
 import 'package:grocery_shop_flutter/components/OrderWidget.dart';
+import 'package:grocery_shop_flutter/models/Cart.dart';
 
 class CartManager extends StatefulWidget {
   @override
-  _CartManager createState() => new _CartManager();
+  _CartManager createState() => _CartManager();
 }
 
 class _CartManager extends State<CartManager> {
 
-  CartBloc _cartBloc = new CartBloc();
+  CartBloc _cartBloc = CartBloc();
 
   @override
   Widget build(BuildContext context) {
+    double _gridSize = MediaQuery.of(context).size.height * 0.88;
 
-    double _gridSize = MediaQuery.of(context).size.height*0.88;
-
-    return new Container(height: MediaQuery.of(context).size.height, child:
-        new Stack(children: <Widget>[
-          new Column(crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[
-            new StreamBuilder(initialData: _cartBloc.currentCart, stream: _cartBloc.observableCart, builder: (context, AsyncSnapshot<Cart> snapshot){
-              return
-                new Container(margin: EdgeInsets.symmetric(horizontal: 20), height: _gridSize, width: double.infinity, child:
-                  new Column(crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[
-                    new Padding(padding: EdgeInsets.symmetric(vertical: 40), child:
-                      new Text("Cart", style: TextStyle(color: Colors.white, fontSize: 40, fontWeight: FontWeight.bold))
-                    ),
-                    new Container(margin: EdgeInsets.only(bottom: 10), height: _gridSize*0.60, child:
-                      new ListView.builder(itemCount: snapshot.data.orders.length, itemBuilder: (context, index ){
-                        return Dismissible(
-                          background: Container(color: Colors.transparent),
-                          key: Key(snapshot.data.orders[index].id.toString()),
-                          onDismissed: (_) {
-                            _cartBloc.removerOrderOfCart(snapshot.data.orders[index]);
-                          },
-                          child: new Padding(padding: EdgeInsets.symmetric(vertical: 10), child: new OrderWidget(snapshot.data.orders[index], _gridSize)),
-                        );
-                      })
-                    ),
-                    new Container(height: _gridSize*0.15, child:
-                      new Row(mainAxisAlignment: MainAxisAlignment.spaceBetween, children: <Widget>[
-                        new Text("Total", style: TextStyle(color: Colors.white, fontSize: 20)),
-                        new Text("\$${snapshot.data.totalPrice().toStringAsFixed(2)}", style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 40)),
-                      ])
-                    )
-                  ])
-                );
-            })
-          ]),
-          new Align(alignment: Alignment.bottomLeft, child:
-            new Container(padding: EdgeInsets.only(left: 10, bottom: _gridSize*0.02), width: MediaQuery.of(context).size.width - 80, child:
-              new RaisedButton(color: Colors.amber, shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(60)), padding: EdgeInsets.all(20),
-                  onPressed: (){
-                    if(_cartBloc.currentCart.isEmpty)
-                      Scaffold.of(context).showSnackBar(SnackBar(content: Text("Cart is empty")));
-                  },
-                  child: new Text("Next", style: TextStyle(fontWeight: FontWeight.bold))
-              )
-            )
-          )
+    return Container(
+        height: MediaQuery.of(context).size.height,
+        child: Stack(children: <Widget>[
+          Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: <Widget>[
+                StreamBuilder(
+                    initialData: _cartBloc.currentCart,
+                    stream: _cartBloc.observableCart,
+                    builder: (context, AsyncSnapshot<Cart> snapshot) {
+                      return Container(
+                          margin: EdgeInsets.symmetric(horizontal: 20),
+                          height: _gridSize,
+                          width: double.infinity,
+                          child: Column(
+                              crossAxisAlignment: CrossAxisAlignment.start,
+                              children: <Widget>[
+                                Padding(
+                                    padding: EdgeInsets.symmetric(vertical: 40),
+                                    child: Text("Cart",
+                                        style: TextStyle(
+                                            color: Colors.white,
+                                            fontSize: 40,
+                                            fontWeight: FontWeight.bold))),
+                                Container(
+                                    margin: EdgeInsets.only(bottom: 10),
+                                    height: _gridSize * 0.60,
+                                    child: ListView.builder(
+                                        itemCount: snapshot.data.orders.length,
+                                        itemBuilder: (context, index) {
+                                          return Dismissible(
+                                            background: Container(
+                                                color: Colors.transparent),
+                                            key: Key(snapshot
+                                                .data.orders[index].id
+                                                .toString()),
+                                            onDismissed: (_) {
+                                              _cartBloc.removerOrderOfCart(
+                                                  snapshot.data.orders[index]);
+                                            },
+                                            child: Padding(
+                                                padding: EdgeInsets.symmetric(
+                                                    vertical: 10),
+                                                child: OrderWidget(
+                                                    snapshot.data.orders[index],
+                                                    _gridSize)),
+                                          );
+                                        })),
+                                Container(
+                                    height: _gridSize * 0.15,
+                                    child: Row(
+                                        mainAxisAlignment:
+                                            MainAxisAlignment.spaceBetween,
+                                        children: <Widget>[
+                                          Text("Total",
+                                              style: TextStyle(
+                                                  color: Colors.white,
+                                                  fontSize: 20)),
+                                          Text(
+                                              "\$${snapshot.data.totalPrice().toStringAsFixed(2)}",
+                                              style: TextStyle(
+                                                  color: Colors.white,
+                                                  fontWeight: FontWeight.bold,
+                                                  fontSize: 40)),
+                                        ]))
+                              ]));
+                    })
+              ]),
+          Align(
+              alignment: Alignment.bottomLeft,
+              child: Container(
+                  padding: EdgeInsets.only(left: 10, bottom: _gridSize * 0.02),
+                  width: MediaQuery.of(context).size.width - 80,
+                  child: RaisedButton(
+                      color: Colors.amber,
+                      shape: RoundedRectangleBorder(
+                          borderRadius: BorderRadius.circular(60)),
+                      padding: EdgeInsets.all(20),
+                      onPressed: () {
+                        if (_cartBloc.currentCart.isEmpty)
+                          Scaffold.of(context).showSnackBar(
+                              SnackBar(content: Text("Cart is empty")));
+                      },
+                      child: Text("Next",
+                          style: TextStyle(fontWeight: FontWeight.bold)))))
         ])
     );
   }

lib/components/CategoryDropMenu.dart

@@ -2,28 +2,33 @@ import 'package:flutter/material.dart';
 
 class CategoryDropMenu extends StatefulWidget {
   @override
-  _CategoryDropMenu createState() => new _CategoryDropMenu();
+  _CategoryDropMenu createState() => _CategoryDropMenu();
 }
 
 class _CategoryDropMenu extends State<CategoryDropMenu> {
 
   String dropdownValue = "Pasta & Noodles";
 
   @override
-  Widget build(BuildContext context){
-    return new DropdownButtonHideUnderline(child:
-      new DropdownButton<String>(
-        value: dropdownValue,
-        onChanged: (String newValue) {
-          setState(() {
-            dropdownValue = newValue;
-          });
-        },
-        items: <String>['Pasta & Noodles'].map<DropdownMenuItem<String>>((String value) {
-          return DropdownMenuItem<String>(
-            value: value,
-            child: Text(value, style: TextStyle(color: Colors.black, fontWeight: FontWeight.bold, fontSize: 20)),
-          );
+  Widget build(BuildContext context) {
+    return DropdownButtonHideUnderline(
+        child: DropdownButton<String>(
+      value: dropdownValue,
+      onChanged: (String Value) {
+        setState(() {
+          dropdownValue = Value;
+        });
+      },
+      items: <String>['Pasta & Noodles']
+          .map<DropdownMenuItem<String>>((String value) {
+        return DropdownMenuItem<String>(
+          value: value,
+          child: Text(value,
+              style: TextStyle(
+                  color: Colors.black,
+                  fontWeight: FontWeight.bold,
+                  fontSize: 20)),
+        );
         }).toList(),
       ));
   }