library stripe_native_card_field;
import 'dart:async';
import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:http/http.dart' as http;
import 'card_details.dart';
import 'card_provider_icon.dart';
/// Enum to track each step of the card detail
/// entry process.
enum CardEntryStep { number, exp, cvc, postal }
// enum LoadingLocation { ontop, rightInside }
/// A uniform text field for entering card details, based
/// on the behavior of Stripe's various html elements.
///
/// Required `width`.
///
/// If the provided `width < 450.0`, the `CardTextField`
/// will scroll its content horizontally with the cursor
/// to compensate.
class CardTextField extends StatefulWidget {
CardTextField({
Key? key,
this.onStripeResponse,
this.onCardDetailsComplete,
required this.width,
this.stripePublishableKey,
this.height,
this.textStyle,
this.hintTextStyle,
this.errorTextStyle,
this.boxDecoration,
this.errorBoxDecoration,
this.loadingWidget,
this.delayToShowLoading = const Duration(milliseconds: 750),
this.overrideValidState,
this.errorText,
// this.loadingWidgetLocation = LoadingLocation.rightInside,
}) : super(key: key) {
if (stripePublishableKey != null) {
assert(stripePublishableKey!.startsWith('pk_'));
if (kReleaseMode && !stripePublishableKey!.startsWith('pk_live_')) {
print('StripeNativeCardField: *WARN* You are not using a live publishableKey in production.');
} else if ((kDebugMode || kProfileMode) && stripePublishableKey!.startsWith('pk_live_')) {
print(
'StripeNativeCardField: *WARN* You are using a live stripe key in a debug environment, proceed with caution!');
print('StripeNativeCardField: *WARN* Ideally you should be using your test keys whenever not in production.');
}
} else {
if (onStripeResponse != null) {
print(
'StripeNativeCardField: *ERROR* You provided the onTokenReceived callback, but did not provide a stripePublishableKey.');
assert(false);
}
}
}
/// Overrides the default box decoration of the text field
final BoxDecoration? boxDecoration;
/// Overrides the default box decoration of the text field when there is a validation error
final BoxDecoration? errorBoxDecoration;
/// Width of the entire CardTextField
final double width;
/// Height of the entire CardTextField
final double? height;
/// Stripe publishable key, starts with 'pk_'
final String? stripePublishableKey;
/// Shown and overrides CircularProgressIndicator() if the request to stripe takes longer than `delayToShowLoading`
final Widget? loadingWidget;
/// Default TextStyle
final TextStyle? textStyle;
/// Default TextStyle for the hint text in each TextFormField
final TextStyle? hintTextStyle;
/// TextStyle used when any TextFormField's have a validation error
final TextStyle? errorTextStyle;
/// Time to wait until showing the loading indicator when retrieving Stripe token
final Duration delayToShowLoading;
/// Determines where the loading indicator appears when contacting stripe
// final LoadingLocation loadingWidgetLocation;
/// Callback that returns the stripe token for the card
final void Function(Map<String, dynamic>)? onStripeResponse;
/// Callback that returns the completed CardDetails object
final void Function(CardDetails)? onCardDetailsComplete;
/// Can manually override the ValidState to surface errors returned from Stripe
final ValidState? overrideValidState;
/// Can manually override the errorText displayed to surface errors returned from Stripe
final String? errorText;
@override
State<CardTextField> createState() => CardTextFieldState();
}
/// State Widget for CardTextField
/// Should not be used directly, create a
/// `CardTextField()` instead.
@visibleForTesting
class CardTextFieldState extends State<CardTextField> {
late TextEditingController _cardNumberController;
late TextEditingController _expirationController;
late TextEditingController _securityCodeController;
late TextEditingController _postalCodeController;
// Not made private for access in widget tests
late FocusNode cardNumberFocusNode;
late FocusNode expirationFocusNode;
late FocusNode securityCodeFocusNode;
late FocusNode postalCodeFocusNode;
// Not made private for access in widget tests
late final bool isWideFormat;
// Widget configurable styles
late final BoxDecoration _normalBoxDecoration;
late final BoxDecoration _errorBoxDecoration;
late final TextStyle _errorTextStyle;
late final TextStyle _normalTextStyle;
late final TextStyle _hintTextSyle;
final double _cardFieldWidth = 180.0;
final double _expirationFieldWidth = 70.0;
final double _securityFieldWidth = 40.0;
final double _postalFieldWidth = 95.0;
late final double _internalFieldWidth;
late final double _expanderWidthExpanded;
late final double _expanderWidthContracted;
String? _validationErrorText;
bool _showBorderError = false;
bool _loading = false;
final CardDetails _cardDetails = CardDetails.blank();
int _prevErrorOverrideHash = 0;
final _currentCardEntryStepController = StreamController<CardEntryStep>();
final _horizontalScrollController = ScrollController();
CardEntryStep _currentStep = CardEntryStep.number;
final _formFieldKey = GlobalKey<FormState>();
@override
void initState() {
_cardNumberController = TextEditingController();
_expirationController = TextEditingController();
_securityCodeController = TextEditingController();
_postalCodeController = TextEditingController();
cardNumberFocusNode = FocusNode();
expirationFocusNode = FocusNode();
securityCodeFocusNode = FocusNode();
postalCodeFocusNode = FocusNode();
_errorTextStyle = const TextStyle(color: Colors.red, fontSize: 14, inherit: true).merge(widget.errorTextStyle);
_normalTextStyle = const TextStyle(color: Colors.black87, fontSize: 14, inherit: true).merge(widget.textStyle);
_hintTextSyle = const TextStyle(color: Colors.black54, fontSize: 14, inherit: true).merge(widget.hintTextStyle);
_normalBoxDecoration = BoxDecoration(
color: const Color(0xfff6f9fc),
border: Border.all(
color: const Color(0xffdde0e3),
width: 2.0,
),
borderRadius: BorderRadius.circular(8.0),
).copyWith(
backgroundBlendMode: widget.boxDecoration?.backgroundBlendMode,
border: widget.boxDecoration?.border,
borderRadius: widget.boxDecoration?.borderRadius,
boxShadow: widget.boxDecoration?.boxShadow,
color: widget.boxDecoration?.color,
gradient: widget.boxDecoration?.gradient,
image: widget.boxDecoration?.image,
shape: widget.boxDecoration?.shape,
);
_errorBoxDecoration = BoxDecoration(
color: const Color(0xfff6f9fc),
border: Border.all(
color: Colors.red,
width: 2.0,
),
borderRadius: BorderRadius.circular(8.0),
).copyWith(
backgroundBlendMode: widget.errorBoxDecoration?.backgroundBlendMode,
border: widget.errorBoxDecoration?.border,
borderRadius: widget.errorBoxDecoration?.borderRadius,
boxShadow: widget.errorBoxDecoration?.boxShadow,
color: widget.errorBoxDecoration?.color,
gradient: widget.errorBoxDecoration?.gradient,
image: widget.errorBoxDecoration?.image,
shape: widget.errorBoxDecoration?.shape,
);
_currentCardEntryStepController.stream.listen(
_onStepChange,
);
RawKeyboard.instance.addListener(_backspaceTransitionListener);
isWideFormat = widget.width >= 450;
if (isWideFormat) {
_internalFieldWidth = widget.width + _postalFieldWidth + 35;
_expanderWidthExpanded = widget.width - _cardFieldWidth - _expirationFieldWidth - _securityFieldWidth - 35;
_expanderWidthContracted =
widget.width - _cardFieldWidth - _expirationFieldWidth - _securityFieldWidth - _postalFieldWidth - 70;
} else {
_internalFieldWidth = _cardFieldWidth + _expirationFieldWidth + _securityFieldWidth + _postalFieldWidth + 80;
}
super.initState();
}
@override
void dispose() {
_cardNumberController.dispose();
_expirationController.dispose();
_securityCodeController.dispose();
cardNumberFocusNode.dispose();
expirationFocusNode.dispose();
securityCodeFocusNode.dispose();
RawKeyboard.instance.removeListener(_backspaceTransitionListener);
super.dispose();
}
@override
Widget build(BuildContext context) {
if ((widget.errorText != null || widget.overrideValidState != null) &&
Object.hashAll([widget.errorText, widget.overrideValidState]) != _prevErrorOverrideHash) {
_prevErrorOverrideHash = Object.hashAll([widget.errorText, widget.overrideValidState]);
_validateFields();
}
return Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Form(
key: _formFieldKey,
child: GestureDetector(
onTap: () {
// Focuses to the current field
_currentCardEntryStepController.add(_currentStep);
},
child: Container(
width: widget.width,
height: widget.height ?? 60.0,
decoration: _showBorderError ? _errorBoxDecoration : _normalBoxDecoration,
child: ClipRect(
child: IgnorePointer(
child: SingleChildScrollView(
controller: _horizontalScrollController,
scrollDirection: Axis.horizontal,
child: SizedBox(
width: _internalFieldWidth,
height: widget.height ?? 60.0,
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.start,
children: [
Padding(
padding: const EdgeInsets.symmetric(horizontal: 6.0),
child: CardProviderIcon(
cardDetails: _cardDetails,
),
),
SizedBox(
width: _cardFieldWidth,
child: TextFormField(
key: const Key('card_field'),
focusNode: cardNumberFocusNode,
controller: _cardNumberController,
keyboardType: TextInputType.number,
style: _isRedText([ValidState.invalidCard, ValidState.missingCard, ValidState.blank])
? _errorTextStyle
: _normalTextStyle,
validator: (content) {
if (content == null || content.isEmpty) {
return null;
}
_cardDetails.cardNumber = content;
if (_cardDetails.validState == ValidState.invalidCard) {
_setValidationState('Your card number is invalid.');
} else if (_cardDetails.validState == ValidState.missingCard) {
_setValidationState('Your card number is incomplete.');
}
return null;
},
onChanged: (str) {
final numbers = str.replaceAll(' ', '');
setState(() => _cardDetails.cardNumber = numbers);
if (str.length <= _cardDetails.maxINNLength) {
_cardDetails.detectCardProvider();
}
if (numbers.length == 16) {
_currentCardEntryStepController.add(CardEntryStep.exp);
}
},
onFieldSubmitted: (_) => _currentCardEntryStepController.add(CardEntryStep.exp),
inputFormatters: [
LengthLimitingTextInputFormatter(19),
FilteringTextInputFormatter.allow(RegExp('[0-9 ]')),
CardNumberInputFormatter(),
],
decoration: InputDecoration(
hintText: 'Card number',
contentPadding: EdgeInsets.zero,
hintStyle: _hintTextSyle,
fillColor: Colors.transparent,
border: InputBorder.none,
),
),
),
if (isWideFormat)
Flexible(
fit: FlexFit.loose,
// fit: _currentStep == CardEntryStep.number ? FlexFit.loose : FlexFit.tight,
child: AnimatedContainer(
curve: Curves.easeInOut,
duration: const Duration(milliseconds: 400),
constraints: _currentStep == CardEntryStep.number
? BoxConstraints.loose(
Size(_expanderWidthExpanded, 0.0),
)
: BoxConstraints.tight(
Size(_expanderWidthContracted, 0.0),
),
),
),
// Spacer(flex: _currentStep == CardEntryStep.number ? 100 : 1),
SizedBox(
width: _expirationFieldWidth,
child: TextFormField(
key: const Key('expiration_field'),
focusNode: expirationFocusNode,
controller: _expirationController,
style: _isRedText([
ValidState.dateTooLate,
ValidState.dateTooEarly,
ValidState.missingDate,
ValidState.invalidMonth
])
? _errorTextStyle
: _normalTextStyle,
validator: (content) {
if (content == null || content.isEmpty) {
return null;
}
setState(() => _cardDetails.expirationString = content);
if (_cardDetails.validState == ValidState.dateTooEarly) {
_setValidationState('Your card\'s expiration date is in the past.');
} else if (_cardDetails.validState == ValidState.dateTooLate) {
_setValidationState('Your card\'s expiration year is invalid.');
} else if (_cardDetails.validState == ValidState.missingDate) {
_setValidationState('You must include your card\'s expiration date.');
} else if (_cardDetails.validState == ValidState.invalidMonth) {
_setValidationState('Your card\'s expiration month is invalid.');
}
return null;
},
onChanged: (str) {
setState(() => _cardDetails.expirationString = str);
if (str.length == 5) {
_currentCardEntryStepController.add(CardEntryStep.cvc);
}
},
onFieldSubmitted: (_) => _currentCardEntryStepController.add(CardEntryStep.cvc),
inputFormatters: [
LengthLimitingTextInputFormatter(5),
FilteringTextInputFormatter.allow(RegExp('[0-9/]')),
CardExpirationFormatter(),
],
decoration: InputDecoration(
contentPadding: EdgeInsets.zero,
hintText: 'MM/YY',
hintStyle: _hintTextSyle,
fillColor: Colors.transparent,
border: InputBorder.none,
),
),
),
SizedBox(
width: _securityFieldWidth,
child: TextFormField(
key: const Key('security_field'),
focusNode: securityCodeFocusNode,
controller: _securityCodeController,
style: _isRedText([ValidState.invalidCVC, ValidState.missingCVC])
? _errorTextStyle
: _normalTextStyle,
validator: (content) {
if (content == null || content.isEmpty) {
return null;
}
setState(() => _cardDetails.securityCode = content);
if (_cardDetails.validState == ValidState.invalidCVC) {
_setValidationState('Your card\'s security code is invalid.');
} else if (_cardDetails.validState == ValidState.missingCVC) {
_setValidationState('Your card\'s security code is incomplete.');
}
return null;
},
onFieldSubmitted: (_) => _currentCardEntryStepController.add(CardEntryStep.postal),
onChanged: (str) {
setState(() => _cardDetails.expirationString = str);
if (str.length == _cardDetails.provider?.cvcLength) {
_currentCardEntryStepController.add(CardEntryStep.postal);
}
},
inputFormatters: [
LengthLimitingTextInputFormatter(
_cardDetails.provider == null ? 4 : _cardDetails.provider!.cvcLength),
FilteringTextInputFormatter.allow(RegExp('[0-9]')),
],
decoration: InputDecoration(
contentPadding: EdgeInsets.zero,
hintText: 'CVC',
hintStyle: _hintTextSyle,
fillColor: Colors.transparent,
border: InputBorder.none,
),
),
),
SizedBox(
width: _postalFieldWidth,
child: TextFormField(
key: const Key('postal_field'),
focusNode: postalCodeFocusNode,
controller: _postalCodeController,
style: _isRedText([ValidState.invalidZip, ValidState.missingZip])
? _errorTextStyle
: _normalTextStyle,
validator: (content) {
if (content == null || content.isEmpty) {
return null;
}
setState(() => _cardDetails.postalCode = content);
if (_cardDetails.validState == ValidState.invalidZip) {
_setValidationState('The postal code you entered is not correct.');
} else if (_cardDetails.validState == ValidState.missingZip) {
_setValidationState('You must enter your card\'s postal code.');
}
return null;
},
onChanged: (str) {
setState(() => _cardDetails.postalCode = str);
},
textInputAction: TextInputAction.done,
onFieldSubmitted: (_) async {
_validateFields();
if (_cardDetails.isComplete) {
if (widget.onCardDetailsComplete != null) {
widget.onCardDetailsComplete!(_cardDetails);
} else if (widget.onStripeResponse != null) {
bool returned = false;
Future.delayed(
const Duration(milliseconds: 750),
() => returned ? null : setState(() => _loading = true),
);
const stripeCardUrl = 'https://api.stripe.com/v1/tokens';
final response = await http.post(
Uri.parse(stripeCardUrl),
body: {
'card[number]': _cardDetails.cardNumber,
'card[cvc]': _cardDetails.securityCode,
'card[exp_month]': _cardDetails.expMonth,
'card[exp_year]': _cardDetails.expYear,
'card[address_zip]': _cardDetails.postalCode,
'key': widget.stripePublishableKey,
},
headers: {"Content-Type": "application/x-www-form-urlencoded"},
);
returned = true;
final jsonBody = jsonDecode(response.body);
widget.onStripeResponse!(jsonBody);
if (_loading) setState(() => _loading = false);
}
}
},
decoration: InputDecoration(
contentPadding: EdgeInsets.zero,
hintText: 'Postal Code',
hintStyle: _hintTextSyle,
fillColor: Colors.transparent,
border: InputBorder.none,
),
),
),
AnimatedOpacity(
duration: const Duration(milliseconds: 300),
opacity: _loading ? 1.0 : 0.0,
child: widget.loadingWidget ?? const CircularProgressIndicator(),
),
],
),
),
),
),
),
),
),
),
AnimatedOpacity(
duration: const Duration(milliseconds: 525),
opacity: _validationErrorText == null ? 0.0 : 1.0,
child: Padding(
padding: const EdgeInsets.only(top: 8.0, left: 14.0),
child: Text(
_validationErrorText ?? '',
style: const TextStyle(color: Colors.red),
),
),
),
],
);
}
/// Provided a list of `ValidState`, returns whether
/// make the text field red
bool _isRedText(List<ValidState> args) {
return _showBorderError && args.contains(_cardDetails.validState);
}
/// Helper function to change the `_showBorderError` and
/// `_validationErrorText`.
void _setValidationState(String? text) {
setState(() {
_validationErrorText = text;
_showBorderError = text != null;
});
}
/// Calls `validate()` on the form state and resets
/// the validation state
void _validateFields() {
_validationErrorText = null;
if (widget.overrideValidState != null) {
_cardDetails.overrideValidState = widget.overrideValidState!;
_setValidationState(widget.errorText);
} else {
_formFieldKey.currentState!.validate();
// Clear up validation state if everything is valid
if (_validationErrorText == null) {
_setValidationState(null);
}
}
return;
}
/// Used when `_isWideFormat == false`, scrolls
/// the `_horizontalScrollController` to a given offset
void _scrollRow(CardEntryStep step) {
const dur = Duration(milliseconds: 150);
const cur = Curves.easeOut;
switch (step) {
case CardEntryStep.number:
_horizontalScrollController.animateTo(0.0, duration: dur, curve: cur);
break;
case CardEntryStep.exp:
_horizontalScrollController.animateTo(_cardFieldWidth / 2, duration: dur, curve: cur);
break;
case CardEntryStep.cvc:
_horizontalScrollController.animateTo(_cardFieldWidth / 2 + _expirationFieldWidth, duration: dur, curve: cur);
break;
case CardEntryStep.postal:
_horizontalScrollController.animateTo(_cardFieldWidth / 2 + _expirationFieldWidth + _securityFieldWidth,
duration: dur, curve: cur);
break;
}
}
/// Function that is listening to the `_currentCardEntryStepController`
/// StreamController. Manages validation and tracking of the current step
/// as well as scrolling the text fields.
void _onStepChange(CardEntryStep step) {
if (_currentStep.index < step.index) {
_validateFields();
} else if (_currentStep != step) {
_setValidationState(null);
}
setState(() {
_currentStep = step;
});
switch (step) {
case CardEntryStep.number:
cardNumberFocusNode.requestFocus();
break;
case CardEntryStep.exp:
expirationFocusNode.requestFocus();
break;
case CardEntryStep.cvc:
securityCodeFocusNode.requestFocus();
break;
case CardEntryStep.postal:
postalCodeFocusNode.requestFocus();
break;
}
if (!isWideFormat) {
_scrollRow(step);
}
}
/// Function that is listening to the keyboard events.
///
/// This provides the functionality of hitting backspace
/// and the focus changing between fields when the current
/// entry step is empty.
void _backspaceTransitionListener(RawKeyEvent value) {
if (!value.isKeyPressed(LogicalKeyboardKey.backspace)) {
return;
}
switch (_currentStep) {
case CardEntryStep.number:
break;
case CardEntryStep.exp:
final expStr = _expirationController.text;
if (expStr.isNotEmpty) break;
_currentCardEntryStepController.add(CardEntryStep.number);
String numStr = _cardNumberController.text;
_cardNumberController.text = numStr.substring(0, numStr.length - 1);
break;
case CardEntryStep.cvc:
final cvcStr = _securityCodeController.text;
if (cvcStr.isNotEmpty) break;
_currentCardEntryStepController.add(CardEntryStep.exp);
final expStr = _expirationController.text;
_expirationController.text = expStr.substring(0, expStr.length - 1);
case CardEntryStep.postal:
final String postalStr = _postalCodeController.text;
if (postalStr.isNotEmpty) break;
_currentCardEntryStepController.add(CardEntryStep.cvc);
final String cvcStr = _securityCodeController.text;
_securityCodeController.text = cvcStr.substring(0, cvcStr.length - 1);
}
}
}
/// Formatter that adds the appropriate space ' ' characters
/// to make the card number display cleanly.
class CardNumberInputFormatter implements TextInputFormatter {
@override
TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
String cardNum = newValue.text;
if (cardNum.length <= 4) return newValue;
cardNum = cardNum.replaceAll(' ', '');
StringBuffer buffer = StringBuffer();
for (int i = 0; i < cardNum.length; i++) {
buffer.write(cardNum[i]);
int nonZeroIndex = i + 1;
if (nonZeroIndex % 4 == 0 && nonZeroIndex != cardNum.length) {
buffer.write(' ');
}
}
return newValue.copyWith(text: buffer.toString(), selection: TextSelection.collapsed(offset: buffer.length));
}
}
/// Formatter that adds a backslash '/' character in between
/// the month and the year for the expiration date.
class CardExpirationFormatter implements TextInputFormatter {
@override
TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
String cardExp = newValue.text;
if (cardExp.length == 1) {
if (cardExp[0] == '0' || cardExp[0] == '1') {
return newValue;
} else {
cardExp = '0$cardExp';
}
}
if (cardExp.length == 2 && oldValue.text.length == 3) return newValue;
cardExp = cardExp.replaceAll('/', '');
StringBuffer buffer = StringBuffer();
for (int i = 0; i < cardExp.length; i++) {
buffer.write(cardExp[i]);
int nonZeroIndex = i + 1;
if (nonZeroIndex == 2) {
buffer.write('/');
}
}
return newValue.copyWith(text: buffer.toString(), selection: TextSelection.collapsed(offset: buffer.length));
}
}