Responsive Container in flutter - flutter

Question

I have a Single child scroll view with child container which I defined the height and width
The problem is when I click on textfield the button is hidden/does not go up. How do I make the height responsive?
#override
Widget build(BuildContext context) {
_width = MediaQuery.of(context).size.width;
_height = MediaQuery.of(context).size.height;
return SingleChildScrollView(
controller: _scrollController,
child: Container(
width: _width,
height: _height,
child: Form(
key: _formKey,
child: Column(
mainAxisSize: MainAxisSize.max,
children: <Widget>[
Expanded(
child: StreamBuilder(
stream: userBloc.user$,
builder: (BuildContext context, AsyncSnapshot snapshot) {
User user = snapshot?.data;
String maskedEmail = _getMaskedEmail(user);
return Column(
children: <Widget>[
widget.instruction != null
? Container(
padding: GenericAssets.paddingSymV10,
child: Text(
widget.instruction,
style: GenericAssets.defaultText,
textAlign: TextAlign.center,
))
: Container(),
(maskedEmail?.isNotEmpty ?? false)
? Column(
children: <Widget>[
Padding(
padding: GenericAssets.paddingSymV10,
child: Text(
S.of(context).strProvideMaskedEmail,
style: GenericAssets.defaultText,
textAlign: TextAlign.center),
),
Padding(
padding: GenericAssets.paddingSymV10,
child: Text(maskedEmail,
style: GenericAssets.defaultText,
textAlign: TextAlign.center),
)
],
)
: Container(),
Container(
child: TextFormField(
style: GenericAssets.defaultText18,
controller: _emailController,
focusNode: _emailFocusNode,
keyboardType: TextInputType.emailAddress,
inputFormatters: [LowerCaseTextFormatter()],
decoration: InputDecoration(
labelText:
S.of(context).fieldEmail.toUpperCase(),
labelStyle: GenericAssets.textFormLabel,
contentPadding:
GenericAssets.textFormFieldSpacing),
validator: (value) {
if (value.isEmpty) {
return S.of(context).msgTextFieldMandatory(
S.of(context).fieldEmail);
}
if (!isEmail(value) ||
!HelperFunctions.isPatternValid(
ProjectConstants.emailPattern, value)) {
return S.of(context).msgPleaseEnterAValidValue(
S.of(context).fieldEmail);
}
return null;
},
),
),
Padding(
padding: GenericAssets.paddingSymV5,
child: PasswordField(
_passwordController,
checkFormat: false,
showPassword: true,
focusNode: _passwordFocusNode,
),
)
],
);
},
),
),
FullWidthButton(
S.of(context).strLogin,
() async {
LoggerService.log(
LogEventType.ButtonPress,
LogDetails(
buttonName: 'Login', displayName: 'Login Screen'));
if (_formKey.currentState.validate()) {
widget.onSubmit(context, widget.authenticationManager,
_passwordController.text, _emailController.text);
}
},
),
InkWell(
onTap: onForgotPassword,
child: Padding(
padding: GenericAssets.padding10,
child: Text(
S.of(context).strForgotPassword,
style: GenericAssets.footNoteLink,
),
),
),
InkWell(
onTap: onResetApp,
child: Padding(
padding: GenericAssets.padding10,
child: Text(
S.of(context).btnResetApplication,
style: GenericAssets.footNoteLink,
),
),
)
],
),
),
),
);
}
I want to show the buttons and other widgets when keyboard is shown.
This is a widget I'm calling it from
#override
Widget build(BuildContext context) {
return WillPopScope(
onWillPop: () => HelperFunctions.logBackpress('Login Screen'),
child: Scaffold(
appBar: AppBar(title: AppBarTitle(S.of(context).strLogin)),
body: StreamBuilder(
stream: manager.loginState$,
builder: (BuildContext context, AsyncSnapshot snapshot) {
bool isLoading = snapshot?.data?.isLoading ?? false;
return Stack(
children: <Widget>[
LoginForm(onSubmit, authenticationManager: manager),
LoadingIndicator(isLoading)
],
);
},
),
),
);
}