Adjust balance calculations

app/lib/helpers/transaction_helpers.dart

@@ -1,10 +1,14 @@
+import 'package:decimal/decimal.dart';
 // ignore: depend_on_referenced_packages
 import 'package:intl/intl.dart';
 
 String formatAmount(String amount) {
-  double parsedAmount = double.parse(amount);
-
+  double parsedAmount = roundAmount(amount).toDouble();
   String formattedAmount = NumberFormat('#,##0.##').format(parsedAmount);
-
   return formattedAmount;
 }
+
+Decimal roundAmount(String amount) {
+  Decimal parsedAmount = Decimal.parse(amount).shift(2).floor().shift(-2);
+  return parsedAmount;
+}

app/lib/screens/wallets/bridge.dart

@@ -1,3 +1,4 @@
+import 'package:decimal/decimal.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:threebotlogin/helpers/globals.dart';
@@ -28,9 +29,11 @@ class _WalletBridgeScreenState extends State<WalletBridgeScreen> {
   final amountController = TextEditingController();
   BridgeOperation transactionType = BridgeOperation.Withdraw;
   bool isWithdraw = true;
+  Decimal fee = Decimal.parse('1.01');
   String? toAddressError;
   String? amountError;
   bool reloadBalance = true;
+  List percentages = [25, 50, 75, 100];
 
   @override
   void initState() {
@@ -86,6 +89,7 @@ class _WalletBridgeScreenState extends State<WalletBridgeScreen> {
     toController.text = '';
     toAddressError = null;
     amountError = null;
+    fee = isWithdraw ? Decimal.parse('1.01') : Decimal.parse('1.1');
     setState(() {});
   }
 
@@ -139,22 +143,16 @@ class _WalletBridgeScreenState extends State<WalletBridgeScreen> {
       amountError = 'Amount should have numeric values only';
       return false;
     }
-    if (double.parse(amount) < 2) {
+    if (Decimal.parse(amount) < Decimal.fromInt(2)) {
       amountError = "Amount can't be less than 2";
       return false;
     }
-    if (isWithdraw) {
-      if (double.parse(amount) > double.parse(widget.wallet.tfchainBalance)) {
-        amountError = "Amount shouldn't be more than the wallet balance";
-        return false;
-      }
-    }
-
-    if (!isWithdraw) {
-      if (double.parse(amount) > double.parse(widget.wallet.stellarBalance)) {
-        amountError = "Amount shouldn't be more than the wallet balance";
-        return false;
-      }
+    final balance = roundAmount(isWithdraw
+        ? widget.wallet.tfchainBalance
+        : widget.wallet.stellarBalance);
+    if (balance - Decimal.parse(amount) - fee < Decimal.zero) {
+      amountError = 'Balance is not enough';
+      return false;
     }
     return true;
   }
@@ -173,15 +171,16 @@ class _WalletBridgeScreenState extends State<WalletBridgeScreen> {
 
   @override
   Widget build(BuildContext context) {
-    String balance = isWithdraw
-        ? widget.wallet.tfchainBalance
-        : widget.wallet.stellarBalance;
     final bool disableDeposit = widget.wallet.stellarBalance == '-1';
-
     if (disableDeposit && !isWithdraw) {
       onTransactionChange(BridgeOperation.Withdraw);
     }
 
+    String balance = isWithdraw
+        ? widget.wallet.tfchainBalance
+        : widget.wallet.stellarBalance;
+    final isBiggerThanFee = roundAmount(balance) > fee;
+
     return Scaffold(
       appBar: AppBar(title: const Text('Bridge')),
       body: SingleChildScrollView(
@@ -252,6 +251,26 @@ class _WalletBridgeScreenState extends State<WalletBridgeScreen> {
               subtitle: Text('Max Fee: ${!isWithdraw ? 1.1 : 1.01} TFT'),
             ),
             const SizedBox(height: 10),
+            if (isBiggerThanFee)
+              Padding(
+                padding: const EdgeInsets.symmetric(horizontal: 15.0),
+                child: Row(
+                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                  children: percentages
+                      .map(
+                        (percentage) => OutlinedButton(
+                          style: OutlinedButton.styleFrom(
+                              shape: const RoundedRectangleBorder(
+                                  borderRadius:
+                                      BorderRadius.all(Radius.circular(5)))),
+                          onPressed: () => calculateAmount(percentage),
+                          child: Text('$percentage%'),
+                        ),
+                      )
+                      .toList(),
+                ),
+              ),
+            const SizedBox(height: 30),
             Padding(
               padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 10),
               child: ElevatedButton(
@@ -279,6 +298,15 @@ class _WalletBridgeScreenState extends State<WalletBridgeScreen> {
     );
   }
 
+  calculateAmount(int percentage) {
+    final amount = (Decimal.parse(isWithdraw
+                ? widget.wallet.tfchainBalance
+                : widget.wallet.stellarBalance) -
+            fee) *
+        (Decimal.fromInt(percentage).shift(-2));
+    amountController.text = roundAmount(amount.toString()).toString();
+  }
+
   _bridge_confirmation() async {
     final memoText =
         !isWithdraw ? await TFChain.getMemo(toController.text.trim()) : null;

app/lib/screens/wallets/send.dart

@@ -1,3 +1,4 @@
+import 'package:decimal/decimal.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_keyboard_visibility/flutter_keyboard_visibility.dart';
@@ -32,7 +33,7 @@ class _WalletSendScreenState extends State<WalletSendScreen> {
   final amountController = TextEditingController();
   final memoController = TextEditingController();
   ChainType chainType = ChainType.Stellar;
-  double fee = 0.1;
+  Decimal fee = Decimal.one.shift(-1); // 0.1
   String? toAddressError;
   String? amountError;
   bool reloadBalance = true;
@@ -90,9 +91,12 @@ class _WalletSendScreenState extends State<WalletSendScreen> {
         ? widget.wallet.stellarAddress
         : widget.wallet.tfchainAddress;
     chainType = type;
-    fee = chainType == ChainType.Stellar
-        ? double.parse('0.1')
-        : double.parse('.01');
+    toController.text = '';
+    toAddressError = null;
+    amountController.text = '';
+    amountError = null;
+    fee = Decimal.one
+        .shift(chainType == ChainType.Stellar ? -1 : -2); // 0.1 : 0.01
     setState(() {});
   }
 
@@ -153,29 +157,14 @@ class _WalletSendScreenState extends State<WalletSendScreen> {
       amountError = 'Amount should have numeric values only';
       return false;
     }
-    if (double.parse(amount) < fee) {
-      amountError = "Amount can't be less than $fee";
+    final balance = roundAmount(chainType == ChainType.TFChain
+        ? widget.wallet.tfchainBalance
+        : widget.wallet.stellarBalance);
+
+    if (balance - Decimal.parse(amount) - fee < Decimal.zero) {
+      amountError = 'Balance is not enough';
       return false;
     }
-    if (chainType == ChainType.TFChain) {
-      // Used epsilon as a tolerance
-      if (double.parse(widget.wallet.tfchainBalance) -
-              double.parse(amount) -
-              fee <
-          -1e-10) {
-        amountError = "Amount shouldn't be more than the wallet balance";
-        return false;
-      }
-    }
-    if (chainType == ChainType.Stellar) {
-      if (double.parse(widget.wallet.stellarBalance) -
-              double.parse(amount) -
-              0.1 <
-          -1e-10) {
-        amountError = "Amount shouldn't be more than the wallet balance";
-        return false;
-      }
-    }
     return true;
   }
 
@@ -193,16 +182,14 @@ class _WalletSendScreenState extends State<WalletSendScreen> {
 
   @override
   Widget build(BuildContext context) {
-    String balance = chainType == ChainType.Stellar
-        ? widget.wallet.stellarBalance
-        : widget.wallet.tfchainBalance;
-    final isBiggerThanFee =
-        percentages.every((p) => double.parse(balance) * p / 100 > fee);
-
     final bool hideStellar = widget.wallet.stellarBalance == '-1';
-    if (hideStellar) {
+    if (hideStellar && chainType == ChainType.Stellar) {
       onChangeChain(ChainType.TFChain);
     }
+    String balance = chainType == ChainType.Stellar
+        ? widget.wallet.stellarBalance
+        : widget.wallet.tfchainBalance;
+    final isBiggerThanFee = roundAmount(balance) > fee;
 
     return Scaffold(
         appBar: AppBar(title: const Text('Send')),
@@ -315,7 +302,7 @@ class _WalletSendScreenState extends State<WalletSendScreen> {
                         child: Text('Max Fee: $fee TFT')),
                   ),
                   const SizedBox(height: 10),
-                  if (double.parse(balance) > fee && isBiggerThanFee)
+                  if (isBiggerThanFee)
                     Padding(
                       padding: const EdgeInsets.symmetric(horizontal: 15.0),
                       child: Row(
@@ -410,12 +397,12 @@ class _WalletSendScreenState extends State<WalletSendScreen> {
   }
 
   calculateAmount(int percentage) {
-    final amount = double.parse(chainType == ChainType.TFChain
+    final amount = (Decimal.parse(chainType == ChainType.TFChain
                 ? widget.wallet.tfchainBalance
-                : widget.wallet.stellarBalance) *
-            (percentage / 100) -
-        fee;
-    amountController.text = amount.toStringAsFixed(2);
+                : widget.wallet.stellarBalance) -
+            fee) *
+        (Decimal.fromInt(percentage).shift(-2));
+    amountController.text = roundAmount(amount.toString()).toString();
   }
 
   _send_confirmation() async {

app/lib/widgets/wallets/bridge_confirmation.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:threebotlogin/helpers/globals.dart';
+import 'package:threebotlogin/helpers/transaction_helpers.dart';
 import 'package:threebotlogin/models/wallet.dart';
 import 'package:threebotlogin/services/stellar_service.dart' as Stellar;
 import 'package:threebotlogin/services/tfchain_service.dart' as TFChain;
@@ -34,13 +35,16 @@ class _BridgeConfirmationWidgetState extends State<BridgeConfirmationWidget> {
   final fromController = TextEditingController();
   final toController = TextEditingController();
   final amountController = TextEditingController();
+  final feeController = TextEditingController();
   bool loading = false;
 
   @override
   void initState() {
     fromController.text = widget.from;
     toController.text = widget.to;
     amountController.text = widget.amount;
+    feeController.text =
+        widget.bridgeOperation == BridgeOperation.Deposit ? '1.1' : '1.01';
     super.initState();
   }
 
@@ -98,9 +102,36 @@ class _BridgeConfirmationWidgetState extends State<BridgeConfirmationWidget> {
                 controller: amountController,
                 decoration: const InputDecoration(
                     labelText: 'Amount', hintText: '100', suffixText: 'TFT')),
-            subtitle: Text(
-                'Max Fee: ${widget.bridgeOperation == BridgeOperation.Deposit ? 1.1 : 1.01} TFT'),
           ),
+          const SizedBox(height: 10),
+          ListTile(
+            title: TextField(
+                readOnly: true,
+                style: Theme.of(context).textTheme.bodyMedium!.copyWith(
+                      color: Theme.of(context).colorScheme.onSurface,
+                    ),
+                keyboardType: TextInputType.number,
+                controller: feeController,
+                decoration:
+                    const InputDecoration(labelText: 'Fee', suffixText: 'TFT')),
+          ),
+          const SizedBox(height: 30),
+          ListTile(
+              leading: Text(
+                'Total',
+                style: Theme.of(context).textTheme.titleLarge!.copyWith(
+                    color: Theme.of(context).colorScheme.onSurface,
+                    fontWeight: FontWeight.bold),
+              ),
+              trailing: Text(
+                (roundAmount(amountController.text) +
+                            roundAmount(feeController.text))
+                        .toString() +
+                    ' TFT',
+                style: Theme.of(context).textTheme.titleLarge!.copyWith(
+                    color: Theme.of(context).colorScheme.onSurface,
+                    fontWeight: FontWeight.bold),
+              )),
           const SizedBox(height: 30),
           Padding(
             padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 10),

app/lib/widgets/wallets/send_confirmation.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:threebotlogin/helpers/transaction_helpers.dart';
 import 'package:threebotlogin/models/wallet.dart';
 import 'package:threebotlogin/services/stellar_service.dart' as Stellar;
 import 'package:threebotlogin/services/tfchain_service.dart' as TFChain;
@@ -32,6 +33,7 @@ class _SendConfirmationWidgetState extends State<SendConfirmationWidget> {
   final fromController = TextEditingController();
   final toController = TextEditingController();
   final amountController = TextEditingController();
+  final feeController = TextEditingController();
   final memoController = TextEditingController();
   bool loading = false;
 
@@ -40,6 +42,7 @@ class _SendConfirmationWidgetState extends State<SendConfirmationWidget> {
     fromController.text = widget.from;
     toController.text = widget.to;
     amountController.text = widget.amount;
+    feeController.text = widget.chainType == ChainType.Stellar ? '0.1' : '0.01';
     memoController.text = widget.memo;
     super.initState();
   }
@@ -99,8 +102,18 @@ class _SendConfirmationWidgetState extends State<SendConfirmationWidget> {
                 controller: amountController,
                 decoration: const InputDecoration(
                     labelText: 'Amount', hintText: '100', suffixText: 'TFT')),
-            subtitle: Text(
-                'Max Fee: ${widget.chainType == ChainType.Stellar ? 0.1 : 0.01} TFT'),
+          ),
+          const SizedBox(height: 10),
+          ListTile(
+            title: TextField(
+                readOnly: true,
+                style: Theme.of(context).textTheme.bodyMedium!.copyWith(
+                      color: Theme.of(context).colorScheme.onSurface,
+                    ),
+                keyboardType: TextInputType.number,
+                controller: feeController,
+                decoration:
+                    const InputDecoration(labelText: 'Fee', suffixText: 'TFT')),
           ),
           const SizedBox(height: 10),
           if (widget.chainType == ChainType.Stellar)
@@ -116,6 +129,22 @@ class _SendConfirmationWidgetState extends State<SendConfirmationWidget> {
                   )),
             ),
           const SizedBox(height: 30),
+          ListTile(
+              leading: Text(
+                'Total',
+                style: Theme.of(context).textTheme.titleLarge!.copyWith(
+                    color: Theme.of(context).colorScheme.onSurface,
+                    fontWeight: FontWeight.bold),
+              ),
+              trailing: Text(
+                (roundAmount(amountController.text) +
+                            roundAmount(feeController.text))
+                        .toString() +
+                    ' TFT',
+                style: Theme.of(context).textTheme.titleLarge!.copyWith(
+                    color: Theme.of(context).colorScheme.onSurface,
+                    fontWeight: FontWeight.bold),
+              )),
           Padding(
             padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 10),
             child: SizedBox(

app/pubspec.lock

@@ -314,13 +314,13 @@ packages:
     source: hosted
     version: "0.7.10"
   decimal:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: decimal
-      sha256: "4140a688f9e443e2f4de3a1162387bf25e1ac6d51e24c9da263f245210f41440"
+      sha256: da8f65df568345f2738cc8b0de74971c86d2d93ce5fc8c4ec094f6b7c5d48eb5
       url: "https://pub.dev"
     source: hosted
-    version: "3.0.2"
+    version: "3.1.0"
   device_info_plus:
     dependency: "direct main"
     description: