Login Page With Checkbox In Flutter Using Android App

flutter: 
  assets: 
   - assets/images/

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Login Screen',
      debugShowCheckedModeBanner: false,
      home: LoginScreen(),
    );
  }
}

class LoginScreen extends StatefulWidget {
  @override
  _LoginScreenState createState() => _LoginScreenState();
}

class _LoginScreenState extends State<LoginScreen> {
  bool _rememberMe = false;

  Widget _Email() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        Text('Email', style: TextStyle(color: Colors.white,fontWeight: FontWeight.bold),),
        SizedBox(height: 10.0),
        Container(
          alignment: Alignment.centerLeft,
          decoration: BoxDecoration(
            color:Colors.deepPurple[200],
            borderRadius: BorderRadius.circular(10.0),
            boxShadow: [
              BoxShadow(
                color: Colors.black12,
                blurRadius: 6.0,
                offset: Offset(0, 3),
              ),
            ],
          ),
          height: 60.0,
          child: TextField(
            keyboardType: TextInputType.emailAddress,
            style: TextStyle(
              color: Colors.white,
            ),
            decoration: InputDecoration(
              border: InputBorder.none,
              contentPadding: EdgeInsets.only(top: 14.0),
              prefixIcon: Icon(
                Icons.email,
                color: Colors.white,
              ),
              hintText: 'Enter your Email',
              hintStyle: TextStyle(color: Colors.white54,),
            ),
          ),
        ),
      ],
    );
  }

  Widget _Password() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        Text('Password', style: TextStyle(color: Colors.white,fontWeight: FontWeight.bold),),
        SizedBox(height: 10.0),
        Container(
          alignment: Alignment.centerLeft,
          decoration:BoxDecoration(
            color:Colors.deepPurple[200],
            borderRadius: BorderRadius.circular(10.0),
            boxShadow: [
              BoxShadow(
                color: Colors.black12,
                blurRadius: 6.0,
                offset: Offset(0, 3),
              ),
            ],
          ),
          height: 60.0,
          child: TextField(
            obscureText: true,
            style: TextStyle(
              color: Colors.white,
            ),
            decoration: InputDecoration(
              border: InputBorder.none,
              contentPadding: EdgeInsets.only(top: 14.0),
              prefixIcon: Icon(
                Icons.lock,
                color: Colors.white,
              ),
              hintText: 'Enter your Password',
              hintStyle: TextStyle(color: Colors.white54,),
            ),
          ),
        ),
        SizedBox(height: 20.0,),
      ],
    );
  }

  Widget _RememberMeCheckbox() {
    return Container(
      height: 20.0,
      child: Row(
        children: <Widget>[
          Theme(
            data: ThemeData(unselectedWidgetColor: Colors.white),
            child: Checkbox(
              value: _rememberMe,
              checkColor: Colors.green,
              activeColor: Colors.white,
              onChanged: (value) {
                setState(() {
                  _rememberMe = value;
                });
              },
            ),
          ),
          Text('Remember me', style: TextStyle(color: Colors.white,fontWeight: FontWeight.bold),),
        ],
      ),
    );
  }

  Widget _LoginBtn() {
    return Container(
      padding: EdgeInsets.symmetric(vertical: 25.0),
      width: double.infinity,
      child: RaisedButton(
        elevation: 5.0,
        onPressed: () => print('Login Button Pressed'),
        padding: EdgeInsets.all(15.0),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(30.0),
        ),
        color: Colors.white,
        child: Text(
          'LOGIN',
          style: TextStyle(
            color: Color(0xFF527DAA),
            letterSpacing: 1.5,
            fontSize: 18.0,
            fontWeight: FontWeight.bold,
          ),
        ),
      ),
    );
  }

  Widget _SignInWithText() {
    return Column(
      children: <Widget>[
        SizedBox(height: 10.0),
        Text('Sign in with', style: TextStyle(color: Colors.white,fontWeight: FontWeight.bold),),
      ],
    );
  }

  Widget _SocialBtn(Function onTap, AssetImage logo) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        height: 60.0,
        width: 60.0,
        decoration: BoxDecoration(
          shape: BoxShape.circle,
          color: Colors.white,
          boxShadow: [
            BoxShadow(
              color: Colors.black26,
              offset: Offset(0, 2),
              blurRadius: 6.0,
            ),
          ],
          image: DecorationImage(
            image: logo,
          ),
        ),
      ),
    );
  }

  Widget _SocialBtnRow() {
    return Padding(
      padding: EdgeInsets.symmetric(vertical: 30.0),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: <Widget>[
          _SocialBtn(
                () => print('Facebook'),
            AssetImage(
              'assets/images/facebook.jpg',
            ),
          ),
          _SocialBtn(
                () => print('Google'),
            AssetImage(
              'assets/images/google.jpg',
            ),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: AnnotatedRegion<SystemUiOverlayStyle>(
        value: SystemUiOverlayStyle.light,
        child: GestureDetector(
          onTap: () => FocusScope.of(context).unfocus(),
          child: Stack(
            children: <Widget>[
              Container(
                height: double.infinity,
                width: double.infinity,
                decoration: BoxDecoration(
                  gradient: LinearGradient(
                    begin: Alignment.topCenter,
                    end: Alignment.bottomCenter,
                    colors: [Color(0xFF9575CD), Color(0xFF9575CD), Color(0xFF9575CD), Color(0xFF9575CD),],
                    stops: [0.1, 0.4, 0.7, 0.9],
                  ),
                ),
              ),
              Container(
                height: double.infinity,
                child: SingleChildScrollView(
                  physics: AlwaysScrollableScrollPhysics(),
                  padding: EdgeInsets.symmetric(
                    horizontal: 40.0,
                    vertical: 120.0,
                  ),
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      Text(
                        'Sign In',
                        style: TextStyle(
                          color: Colors.white,
                          fontSize: 30.0,
                          fontWeight: FontWeight.bold,
                        ),
                      ),
                      SizedBox(height: 30.0),
                      _Email(),
                     SizedBox(height: 30.0,),
                      _Password(),
                      _RememberMeCheckbox(),
                      _LoginBtn(),
                      _SignInWithText(),
                      _SocialBtnRow(),
                    ],
                  ),
                ),
              )
            ],
          ),
        ),
      ),
    );
  }
}