CW-1017: Monero minor enhancements (#2347)

* feat: add max decimal handling for crypto amounts and test coverage

* fix: correct decimal point handling in `withMaxDecimals` and update related test

* fix: ensure amount formatting aligns with selected currency decimals in ReceivePage

* fix: ensure amount controller syncs with ViewModel in AddressPage and ReceivePage

* feat: add support for currency decimals and streamline amount handling logic

* fix: ensure crypto and fiat amounts sync correctly in Send ViewModel

cw_core/lib/crypto_amount_format.dart

@@ -1 +1,17 @@
-double cryptoAmountToDouble({required num amount, required num divider}) => amount / divider;
+double cryptoAmountToDouble({required num amount, required num divider}) => amount / divider;
+
+extension MaxDecimals on String {
+  String withMaxDecimals(int maxDecimals) {
+    var parts = split(".");
+
+    if (parts.length > 2) {
+      parts = [parts.first, parts.sublist(1, parts.length).join("")];
+    }
+
+    if (parts.length == 2 && parts[1].length > maxDecimals) {
+      parts[1] = parts[1].substring(0, maxDecimals);
+    }
+
+    return parts.join(".");
+  }
+}

cw_core/lib/currency.dart

@@ -3,4 +3,5 @@ abstract class Currency {
   String? get tag;
   String? get fullName;
   String? get iconPath;
-}
+  int get decimals;
+}

cw_core/test/crypto_amount_format.dart

@@ -0,0 +1,34 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:cw_core/crypto_amount_format.dart';
+
+void main() {
+  group('String.withMaxDecimals', () {
+    test('should return the original string when it has fewer decimal places than the max', () {
+      final input = '123.45';
+      final result = input.withMaxDecimals(3);
+      
+      expect(result, equals(input));
+    });
+
+    test('should truncate decimal places when the string has more than the max', () {
+      final input = '123.4567';
+      final result = input.withMaxDecimals(2);
+      
+      expect(result, equals('123.45'));
+    });
+
+    test('should handle strings with no decimal places', () {
+      final input = '123';
+      final result = input.withMaxDecimals(2);
+      
+      expect(result, equals(input));
+    });
+
+    test('should handle strings with multiple decimal points', () {
+      final input = '123.45.67';
+      final result = input.withMaxDecimals(4);
+      
+      expect(result, equals('123.4567'));
+    });
+  });
+}

lib/entities/fiat_currency.dart

@@ -2,10 +2,16 @@ import 'package:cw_core/currency.dart';
 import 'package:cw_core/enumerable_item.dart';
 
 class FiatCurrency extends EnumerableItem<String> with Serializable<String> implements Currency {
-  const FiatCurrency({required String symbol, required this.countryCode, required this.fullName}) : super(title: symbol, raw: symbol);
+  const FiatCurrency({
+    required String symbol,
+    required this.countryCode,
+    required this.fullName,
+    this.decimals = 2,
+  }) : super(title: symbol, raw: symbol);
 
   final String countryCode;
   final String fullName;
+  final int decimals;
 
   static List<FiatCurrency> get all => _all.values.toList();
 

lib/src/screens/dashboard/pages/address_page.dart

@@ -8,7 +8,6 @@ import 'package:cw_core/receive_page_option.dart';
 import 'package:cake_wallet/src/screens/dashboard/widgets/present_receive_option_picker.dart';
 import 'package:cake_wallet/src/widgets/gradient_background.dart';
 import 'package:cake_wallet/src/widgets/keyboard_done_button.dart';
-import 'package:cake_wallet/themes/core/material_base_theme.dart';
 import 'package:cake_wallet/utils/responsive_layout_util.dart';
 import 'package:cake_wallet/utils/share_util.dart';
 import 'package:cake_wallet/view_model/dashboard/receive_option_view_model.dart';
@@ -34,9 +33,7 @@ class AddressPage extends BasePage {
         _amountController = TextEditingController() {
     _amountController.addListener(() {
       if (_formKey.currentState!.validate()) {
-        addressListViewModel.changeAmount(
-          _amountController.text,
-        );
+        addressListViewModel.changeAmount(_amountController.text);
       }
     });
   }
@@ -79,7 +76,7 @@ class AddressPage extends BasePage {
             label: !isMobileView ? S.of(context).close : S.of(context).seed_alert_back,
             child: TextButton(
               style: ButtonStyle(
-                overlayColor: MaterialStateColor.resolveWith((states) => Colors.transparent),
+                overlayColor: WidgetStateColor.resolveWith((states) => Colors.transparent),
               ),
               onPressed: () => onClose(context),
               child: !isMobileView ? _closeButton : _backButton,

lib/src/screens/exchange/widgets/exchange_card.dart

@@ -225,6 +225,7 @@ class ExchangeCardState<T extends Currency> extends State<ExchangeCard<T>> {
                 ValueKey('${_cardInstanceName}_currency_amount_textfield_widget_key'),
             imageArrow: widget.imageArrow,
             selectedCurrency: _selectedCurrency.toString(),
+            selectedCurrencyDecimals: _selectedCurrency.decimals,
             amountFocusNode: widget.amountFocusNode,
             amountController: amountController,
             onTapPicker: () => _presentPicker(context),

lib/src/screens/receive/widgets/currency_input_field.dart

@@ -1,12 +1,14 @@
 import 'package:cake_wallet/generated/i18n.dart';
 import 'package:cake_wallet/src/widgets/base_text_form_field.dart';
 import 'package:cake_wallet/themes/core/material_base_theme.dart';
+import 'package:cw_core/crypto_amount_format.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
 class CurrencyAmountTextField extends StatelessWidget {
   const CurrencyAmountTextField({
     required this.selectedCurrency,
+    required this.selectedCurrencyDecimals,
     required this.amountFocusNode,
     required this.amountController,
     required this.isAmountEditable,
@@ -42,6 +44,7 @@ class CurrencyAmountTextField extends StatelessWidget {
   final Key? currencyAmountTextFieldWidgetKey;
   final Widget? imageArrow;
   final String selectedCurrency;
+  final int selectedCurrencyDecimals;
   final String? tag;
   final String? hintText;
   final Color? tagBackgroundColor;
@@ -197,6 +200,8 @@ class CurrencyAmountTextField extends StatelessWidget {
                             color: Theme.of(context).colorScheme.onSurfaceVariant,
                           ),
                       validator: isAmountEditable ? currencyValueValidator : null,
+                      onChanged: (value) => amountController.text =
+                          value.replaceAll(',', '.').withMaxDecimals(selectedCurrencyDecimals),
                     ),
                   ),
                 ),

lib/src/screens/receive/widgets/qr_widget.dart

@@ -211,6 +211,8 @@ class QRWidget extends StatelessWidget {
                                 hasUnderlineBorder: true,
                                 borderWidth: 0.0,
                                 selectedCurrency: _currencyName,
+                                selectedCurrencyDecimals:
+                                    addressListViewModel.selectedCurrency.decimals,
                                 amountFocusNode: amountTextFieldFocusNode,
                                 amountController: amountController,
                                 padding: EdgeInsets.only(top: 20, left: _width / 4),

lib/src/screens/send/widgets/send_card.dart

@@ -247,6 +247,7 @@ class SendCardState extends State<SendCard> with AutomaticKeepAliveClientMixin<S
                 currencyAmountTextFieldWidgetKey:
                     ValueKey('send_page_crypto_currency_amount_textfield_widget_key'),
                 selectedCurrency: sendViewModel.selectedCryptoCurrency.title,
+                selectedCurrencyDecimals: sendViewModel.selectedCryptoCurrency.decimals,
                 amountFocusNode: widget.cryptoAmountFocus,
                 amountController: cryptoAmountController,
                 isAmountEditable: true,
@@ -308,6 +309,7 @@ class SendCardState extends State<SendCard> with AutomaticKeepAliveClientMixin<S
                   currencyAmountTextFieldWidgetKey:
                       ValueKey('send_page_fiat_currency_amount_textfield_widget_key'),
                   selectedCurrency: sendViewModel.fiat.title,
+                  selectedCurrencyDecimals: sendViewModel.fiat.decimals,
                   amountFocusNode: widget.fiatAmountFocus,
                   amountController: fiatAmountController,
                   hintText: '0.00',

lib/src/screens/send/widgets/send_template_card.dart

@@ -122,6 +122,7 @@ class SendTemplateCard extends StatelessWidget {
                           hasUnderlineBorder: true,
                           borderWidth: 0.0,
                           selectedCurrency: template.selectedCurrency.title,
+                          selectedCurrencyDecimals: template.selectedCurrency.decimals,
                           amountFocusNode: _cryptoAmountFocus,
                           amountController: _cryptoAmountController,
                           isSelected: template.isCryptoSelected,
@@ -148,6 +149,7 @@ class SendTemplateCard extends StatelessWidget {
                           hasUnderlineBorder: true,
                           borderWidth: 0.0,
                           selectedCurrency: sendTemplateViewModel.fiatCurrency,
+                          selectedCurrencyDecimals: sendTemplateViewModel.fiatCurrencyDecimals,
                           amountFocusNode: _fiatAmountFocus,
                           amountController: _fiatAmountController,
                           isSelected: !template.isCryptoSelected,

lib/view_model/send/output.dart

@@ -250,7 +250,7 @@ abstract class OutputBase with Store {
       sendAll = false;
     }
 
-    cryptoAmount = amount.replaceAll(',', '.');
+    cryptoAmount = amount;
     _updateFiatAmount();
   }
 

lib/view_model/send/send_template_view_model.dart

@@ -63,6 +63,9 @@ abstract class SendTemplateViewModelBase with Store {
   @computed
   String get fiatCurrency => _settingsStore.fiatCurrency.title;
 
+  @computed
+  int get fiatCurrencyDecimals => _settingsStore.fiatCurrency.decimals;
+
   @computed
   ObservableList<Template> get templates => _sendTemplateStore.templates;