Accessing a function from one to another dart class - flutter

Question

I am new to flutter. I have class name LoginCard.dart in this I have another class named _FormPageState which have _validateInputs function `
import 'package:firstapp/Future/app_futures.dart';
import 'package:firstapp/Models/Base/EventObject.dart';
import 'package:firstapp/Widgets/SignupCard.dart';
import 'package:firstapp/utils/constants.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:firstapp/Components/ProgressDialog.dart';
class LoginCard extends StatelessWidget {
#override
Widget build (BuildContext context){
return new Container(
child: new LoginFormContainer(),
);
}
}
class LoginFormContainer extends StatefulWidget{
// #override
// _FormPageState createState() => _FormPageState();
State<StatefulWidget> createState() {
return _FormPageState();
}
}
class _FormPageState extends State<LoginFormContainer>{
final GlobalKey<FormState> _formKey = new GlobalKey<FormState>();
bool _autoValidate = false;
// bool _obscureText = true;
String _email;
String _password;
ProgressDialog progressDialog = ProgressDialog
.getProgressDialog(ProgressDialogTitles.USER_LOG_IN);
#override
Widget build(BuildContext context) {
return new Container(
width: double.infinity,
height: ScreenUtil.getInstance().setHeight(500),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(8.0),
boxShadow: [
BoxShadow(
color: Colors.black12,
offset: Offset(0.0, 15.0),
blurRadius: 15.0),
BoxShadow(
color: Colors.black12,
offset: Offset(0.0, -10.0),
blurRadius: 10.0),
]),
child: Padding(
padding: EdgeInsets.only(left: 16.0, right: 16.0, top: 16.0),
child: new Form(
key: _formKey,
autovalidate: _autoValidate,
child: new Stack(
children: <Widget>[loginFormUI(), progressDialog]
)
),
),
);
}
Widget loginFormUI(){
return new Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text("Login",
style: TextStyle(
fontSize: ScreenUtil.getInstance().setSp(45),
fontFamily: "Poppins-Bold",
letterSpacing: .6)),
SizedBox(
height: ScreenUtil.getInstance().setHeight(30),
),
Text("Username",
style: TextStyle(
fontFamily: "Poppins-Medium",
fontSize: ScreenUtil.getInstance().setSp(26))),
new TextFormField(
autofocus: true,
keyboardType: TextInputType.text,
validator: validateEmail,
onSaved: (val) =>
_email = val,
decoration: InputDecoration(
hintText: "username",
hintStyle: TextStyle(color: Colors.grey, fontSize: 12.0)),
),
SizedBox(
height: ScreenUtil.getInstance().setHeight(30),
),
Text("Password",
style: TextStyle(
fontFamily: "Poppins-Medium",
fontSize: ScreenUtil.getInstance().setSp(26))),
new TextFormField(
obscureText: true,
keyboardType: TextInputType.text,
validator: validatePassword,
onSaved: (val) =>
_password = val,
decoration: InputDecoration(
hintText: "Password",
hintStyle: TextStyle(color: Colors.grey, fontSize: 12.0)),
),
SizedBox(
height: ScreenUtil.getInstance().setHeight(35),
),
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
Text(
"Forgot Password?",
style: TextStyle(
color: Colors.blue,
fontFamily: "Poppins-Medium",
fontSize: ScreenUtil.getInstance().setSp(28)),
)
],
)
],
);
}
String validateEmail(String value){
Pattern pattern = r'^(([^<>()[\]\\.,;:\s#\"]+(\.[^<>()[\]\\.,;:\s#\"]+)*)|(\".+\"))#((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$';
RegExp regex = new RegExp(pattern);
if(value.isEmpty)
return "Email is required";
else if(!regex.hasMatch(value))
return 'Enter valid email';
else
return null;
}
String validatePassword(String value){
if (value.isEmpty)
return "Password is required";
else
return null;
}
void _validateInputs() {
if (_formKey.currentState.validate()){
print("hello");
// If all data are correct then save data to out variables
_formKey.currentState.save();
FocusScope.of(context).requestFocus(new FocusNode());
progressDialog.showProgress();
// _addNewUser();
_performLogin();
} else {
// If all data are not valid then start auto validation.
setState(() {
_autoValidate = true;
});
}
}
void _performLogin() async{
EventObject eventObject = await performLogin(_email, _password);
}
}
`
and Another class name is main.dart `
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'Widgets/LoginCard.dart';
import 'Widgets/SocialIcons.dart';
import 'CustomIcons.dart';
import 'signup.dart';
//
void main() => runApp(MaterialApp(
home: MyApp(),
debugShowCheckedModeBanner: false,
));
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => new _MyAppState();
}
class _MyAppState extends State<MyApp> {
bool _isSelected = false;
// _FormPageState formPageState;
void _radio() {
setState(() {
_isSelected = !_isSelected;
});
}
Widget radioButton(bool isSelected) => Container(
width: 16.0,
height: 16.0,
padding: EdgeInsets.all(2.0),
decoration: BoxDecoration(
shape: BoxShape.circle,
border: Border.all(width: 2.0, color: Colors.black)),
child: isSelected
? Container(
width: double.infinity,
height: double.infinity,
decoration:
BoxDecoration(shape: BoxShape.circle, color: Colors.black),
)
: Container(),
);
Widget horizontalLine() => Padding(
padding: EdgeInsets.symmetric(horizontal: 16.0),
child: Container(
width: ScreenUtil.getInstance().setWidth(120),
height: 1.0,
color: Colors.black26.withOpacity(.2),
),
);
#override
Widget build(BuildContext context) {
ScreenUtil.instance = ScreenUtil.getInstance()..init(context);
ScreenUtil.instance =
ScreenUtil(width: 750, height: 1334, allowFontScaling: true);
return new Scaffold(
backgroundColor: Colors.white,
resizeToAvoidBottomPadding: true,
body: Stack(
fit: StackFit.expand,
children: <Widget>[
Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
Padding(
padding: EdgeInsets.only(top: 100.0),
child: Image.asset("assets/carscartoon.png"),
),
Expanded(
child: Container(),
),
Image.asset("assets/image_02.png")
],
),
SingleChildScrollView(
child: Padding(
padding: EdgeInsets.only(left: 28.0, right: 28.0, top: 60.0),
child: Column(
children: <Widget>[
Row(
children: <Widget>[
Image.asset(
"assets/tlrlogo.png",
width: ScreenUtil.getInstance().setWidth(110),
height: ScreenUtil.getInstance().setHeight(110),
),
Text("Transport Levy Record",
style: TextStyle(
fontFamily: "Poppins-Bold",
fontSize: ScreenUtil.getInstance().setSp(30),
letterSpacing: .6,
fontWeight: FontWeight.bold))
],
),
SizedBox(
height: ScreenUtil.getInstance().setHeight(180),
),
LoginCard(),
SizedBox(height: ScreenUtil.getInstance().setHeight(40)),
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
children: <Widget>[
SizedBox(
width: 12.0,
),
GestureDetector(
onTap: _radio,
child: radioButton(_isSelected),
),
SizedBox(
width: 8.0,
),
Text("Remember me",
style: TextStyle(
fontSize: 12, fontFamily: "Poppins-Medium"))
],
),
InkWell(
child: Container(
width: ScreenUtil.getInstance().setWidth(330),
height: ScreenUtil.getInstance().setHeight(100),
decoration: BoxDecoration(
gradient: LinearGradient(colors: [
Color(0xFF17ead9),
Color(0xFF6078ea)
]),
borderRadius: BorderRadius.circular(6.0),
boxShadow: [
BoxShadow(
color: Color(0xFF6078ea).withOpacity(.3),
offset: Offset(0.0, 8.0),
blurRadius: 8.0)
]),
child: Material(
color: Colors.transparent,
child: InkWell(
onTap: () {
// LoginFormContainer()
},
child: Center(
child: Text("SIGNIN",
style: TextStyle(
color: Colors.white,
fontFamily: "Poppins-Bold",
fontSize: 18,
letterSpacing: 1.0)),
),
),
),
),
)
],
),
SizedBox(
height: ScreenUtil.getInstance().setHeight(40),
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
horizontalLine(),
Text("Social Login",
style: TextStyle(
fontSize: 16.0, fontFamily: "Poppins-Medium")),
horizontalLine()
],
),
SizedBox(
height: ScreenUtil.getInstance().setHeight(40),
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
SocialIcons(
colors: [
Color(0xFF102397),
Color(0xFF187adf),
Color(0xFF00eaf8),
],
iconData: CustomIcons.facebook,
onPressed: () {},
),
SocialIcons(
colors: [
Color(0xFFff4f38),
Color(0xFFff355d),
],
iconData: CustomIcons.googlePlus,
onPressed: () {},
),
SocialIcons(
colors: [
Color(0xFF17ead9),
Color(0xFF6078ea),
],
iconData: CustomIcons.twitter,
onPressed: () {},
),
SocialIcons(
colors: [
Color(0xFF00c6fb),
Color(0xFF005bea),
],
iconData: CustomIcons.linkedin,
onPressed: () {},
)
],
),
SizedBox(
height: ScreenUtil.getInstance().setHeight(30),
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
"New User? ",
style: TextStyle(fontFamily: "Poppins-Medium"),
),
InkWell(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(builder:
(context) => Signup()));
},
child: Text("SignUp",
style: TextStyle(
color: Color(0xFF5d74e3),
fontFamily: "Poppins-Bold")),
)
],
)
],
),
),
)
],
),
);
}
}
`
On line No. 143 there is onTap function of SignIn button in my main.dart class, I want access _validateInputs() function of _FormPageState.
I am new in dart. Please let me know, if any solution for this.

Answer 1

Put _validateInputs() function and all variables in main.dart file which is used in LoginCard.dart file and pass variables to Logincard constructor as argument from main.dart file.
In main.dart file
final GlobalKey<FormState> _formKey = new GlobalKey<FormState>();
pass _formkey to LoginCard() constructor
LoginCard(_formKey);
in LoginCard.dart file
class LoginCard extends StatelessWidget {
final GlobalKey<FormState> formKey;
LoginCard(this.formKey);
#override
Widget build (BuildContext context){
return new Container();
}