created constant file moved all colors there

overall app maintained same color

Author: thamaraiselvam

TODO

@@ -1,11 +1,8 @@
 
 Todo:
   ☐ Replace Wrap to somethings else
-  ☐ Design Home page
   ☐ Vibrate when wrong item selected
   ☐ Store recent scores in local storage
-  ☐ Plan/remove Rank
-  ☐ Icon rethink
   ☐ Code refactor
   ☐ Add constant file
   ☐ Write test cases

lib/main.dart

@@ -1,11 +1,18 @@
+import 'package:flutter/services.dart';
 import 'package:numbers/screens/GameScreen.dart';
 import 'package:numbers/screens/HowToScreen.dart';
 import 'package:numbers/screens/LoadingScreen.dart';
 import 'package:flutter/material.dart';
 import 'package:numbers/screens/SplashScreen.dart';
 import 'package:numbers/screens/homeScreen.dart';
 
-void main() => runApp(new MaterialApp(
+Future<void> main() async {
+  SystemChrome.setPreferredOrientations([
+        DeviceOrientation.portraitUp,
+        DeviceOrientation.portraitDown,
+      ]);
+  runApp(
+    new MaterialApp(
       initialRoute: '/',
       routes: <String, WidgetBuilder> {
         '/': (BuildContext context) => SplashScreen(),
@@ -15,3 +22,4 @@ void main() => runApp(new MaterialApp(
         '/howTo': (BuildContext context) => HowToScreen(),
       },
     ));
+}

lib/screens/GameScreen.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 import 'package:numbers/schema/blackSchema.dart';
+import 'package:numbers/utils/constants.dart';
 import 'package:numbers/widgets/bgGradient.dart';
 import 'package:numbers/provider/BlockDataStream.dart';
 import 'package:numbers/widgets/targetBlockBuilder.dart';
@@ -28,7 +29,35 @@ class _GameScreenState extends State<GameScreen> {
     this.listenBlockChanges();
   }
 
-  void initTimer() {
+  @override
+  Widget build(BuildContext context) {
+    return SafeArea(
+      child: Scaffold(
+        body: Container(
+          height: double.infinity,
+          decoration: bgBoxDecoration(),
+          child: SingleChildScrollView(
+            child: Column(
+              children: <Widget>[
+                SizedBox(
+                  height: 10,
+                ),
+                _headerInfo(),
+                SizedBox(
+                  height: 10,
+                ),
+                buildTargetBlock(
+                    title: 'Target', targetValue: this.blockSchema.target),
+                buildNumberBlocks()
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+   void initTimer() {
     this.gameTimerObject = Timer.periodic(Duration(seconds: 1), (timer) {
       setState(() {
         this.secCounter--;
@@ -129,39 +158,14 @@ class _GameScreenState extends State<GameScreen> {
     this.blocks[selectedIndex].color = color;
   }
 
-  @override
-  Widget build(BuildContext context) {
-    return SafeArea(
-      child: Scaffold(
-        body: Container(
-          decoration: bgBoxDecoration(),
-          child: Column(
-            children: <Widget>[
-              SizedBox(
-                height: 10,
-              ),
-              _headerInfo(),
-              SizedBox(
-                height: 10,
-              ),
-              buildTargetBlock(
-                  title: 'Target', targetValue: this.blockSchema.target),
-              buildNumberBlocks()
-            ],
-          ),
-        ),
-      ),
-    );
-  }
-
   Row _headerInfo() {
     return Row(
       mainAxisAlignment: MainAxisAlignment.center,
       children: <Widget>[
         Container(
             padding: const EdgeInsets.only(left: 15, right: 10),
             width: 100,
-            color: Colors.red,
+            color: blackLowOpacity,
             child: Row(
               children: <Widget>[
                 Text(
@@ -181,7 +185,7 @@ class _GameScreenState extends State<GameScreen> {
             margin: const EdgeInsets.only(left: 10),
             padding: const EdgeInsets.only(left: 15, right: 10),
             width: 100,
-            color: Colors.green,
+            color: blackLowOpacity,
             child: Row(
               children: <Widget>[
                 Text(