Merge pull request #1361 from cypherstack/fix/305-multiline-transaction-notes

### lib/pages/exchange_view/edit_trade_note_view.dart
@@ -62,15 +62,16 @@ class _EditNoteViewState extends ConsumerState<EditTradeNoteView> {
       child: Scaffold(
         backgroundColor: Theme.of(context).extension<StackColors>()!.background,
         appBar: AppBar(
-          backgroundColor:
-              Theme.of(context).extension<StackColors>()!.background,
+          backgroundColor: Theme.of(context)
+              .extension<StackColors>()!
+              .background,
           leading: AppBarBackButton(
             onPressed: () async {
               if (FocusScope.of(context).hasFocus) {
                 FocusScope.of(context).unfocus();
                 await Future<void>.delayed(const Duration(milliseconds: 75));
               }
-              if (mounted) {
+              if (context.mounted) {
                 Navigator.of(context).pop();
               }
             },
@@ -102,41 +103,47 @@ class _EditNoteViewState extends ConsumerState<EditTradeNoteView> {
                               ),
                               child: TextField(
                                 autocorrect: Util.isDesktop ? false : true,
-                                enableSuggestions:
-                                    Util.isDesktop ? false : true,
+                                enableSuggestions: Util.isDesktop
+                                    ? false
+                                    : true,
+                                minLines: 3,
+                                maxLines: 6,
+                                keyboardType: TextInputType.multiline,
+                                textInputAction: TextInputAction.newline,
                                 controller: _noteController,
                                 style: STextStyles.field(context),
                                 focusNode: noteFieldFocusNode,
                                 onChanged: (_) => setState(() {}),
-                                decoration: standardInputDecoration(
-                                  "Note",
-                                  noteFieldFocusNode,
-                                  context,
-                                ).copyWith(
-                                  suffixIcon:
-                                      _noteController.text.isNotEmpty
+                                decoration:
+                                    standardInputDecoration(
+                                      "Note",
+                                      noteFieldFocusNode,
+                                      context,
+                                    ).copyWith(
+                                      suffixIcon:
+                                          _noteController.text.isNotEmpty
                                           ? Padding(
-                                            padding: const EdgeInsets.only(
-                                              right: 0,
-                                            ),
-                                            child: UnconstrainedBox(
-                                              child: Row(
-                                                children: [
-                                                  TextFieldIconButton(
-                                                    child: const XIcon(),
-                                                    onTap: () async {
-                                                      setState(() {
-                                                        _noteController.text =
-                                                            "";
-                                                      });
-                                                    },
-                                                  ),
-                                                ],
+                                              padding: const EdgeInsets.only(
+                                                right: 0,
                                               ),
-                                            ),
-                                          )
+                                              child: UnconstrainedBox(
+                                                child: Row(
+                                                  children: [
+                                                    TextFieldIconButton(
+                                                      child: const XIcon(),
+                                                      onTap: () async {
+                                                        setState(() {
+                                                          _noteController.text =
+                                                              "";
+                                                        });
+                                                      },
+                                                    ),
+                                                  ],
+                                                ),
+                                              ),
+                                            )
                                           : null,
-                                ),
+                                    ),
                               ),
                             ),
                             const Spacer(),
@@ -148,7 +155,7 @@ class _EditNoteViewState extends ConsumerState<EditTradeNoteView> {
                                       tradeId: widget.tradeId,
                                       note: _noteController.text,
                                     );
-                                if (mounted) {
+                                if (context.mounted) {
                                   Navigator.of(context).pop();
                                 }
                               },

### lib/pages/wallet_view/transaction_views/edit_note_view.dart
@@ -71,34 +71,33 @@ class _EditNoteViewState extends ConsumerState<EditNoteView> {
       condition: !isDesktop,
       builder: (child) => Background(child: child),
       child: Scaffold(
-        backgroundColor:
-            isDesktop
-                ? Colors.transparent
-                : Theme.of(context).extension<StackColors>()!.background,
-        appBar:
-            isDesktop
-                ? null
-                : AppBar(
-                  backgroundColor:
-                      Theme.of(context).extension<StackColors>()!.background,
-                  leading: AppBarBackButton(
-                    onPressed: () async {
-                      if (FocusScope.of(context).hasFocus) {
-                        FocusScope.of(context).unfocus();
-                        await Future<void>.delayed(
-                          const Duration(milliseconds: 75),
-                        );
-                      }
-                      if (mounted) {
-                        Navigator.of(context).pop();
-                      }
-                    },
-                  ),
-                  title: Text(
-                    "Edit note",
-                    style: STextStyles.navBarTitle(context),
-                  ),
+        backgroundColor: isDesktop
+            ? Colors.transparent
+            : Theme.of(context).extension<StackColors>()!.background,
+        appBar: isDesktop
+            ? null
+            : AppBar(
+                backgroundColor: Theme.of(context)
+                    .extension<StackColors>()!
+                    .background,
+                leading: AppBarBackButton(
+                  onPressed: () async {
+                    if (FocusScope.of(context).hasFocus) {
+                      FocusScope.of(context).unfocus();
+                      await Future<void>.delayed(
+                        const Duration(milliseconds: 75),
+                      );
+                    }
+                    if (context.mounted) {
+                      Navigator.of(context).pop();
+                    }
+                  },
                 ),
+                title: Text(
+                  "Edit note",
+                  style: STextStyles.navBarTitle(context),
+                ),
+              ),
         body: MobileEditNoteScaffold(
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.stretch,
@@ -115,72 +114,70 @@ class _EditNoteViewState extends ConsumerState<EditNoteView> {
                   ),
                 ),
               Padding(
-                padding:
-                    isDesktop
-                        ? const EdgeInsets.symmetric(horizontal: 32)
-                        : const EdgeInsets.all(0),
+                padding: isDesktop
+                    ? const EdgeInsets.symmetric(horizontal: 32)
+                    : const EdgeInsets.all(0),
                 child: ClipRRect(
                   borderRadius: BorderRadius.circular(
                     Constants.size.circularBorderRadius,
                   ),
                   child: TextField(
                     autocorrect: Util.isDesktop ? false : true,
                     enableSuggestions: Util.isDesktop ? false : true,
+                    minLines: 3,
+                    maxLines: 6,
+                    keyboardType: TextInputType.multiline,
+                    textInputAction: TextInputAction.newline,
                     controller: _noteController,
-                    style:
-                        isDesktop
-                            ? STextStyles.desktopTextExtraSmall(
-                              context,
-                            ).copyWith(
-                              color:
-                                  Theme.of(context)
-                                      .extension<StackColors>()!
-                                      .textFieldActiveText,
-                              height: 1.8,
-                            )
-                            : STextStyles.field(context),
+                    style: isDesktop
+                        ? STextStyles.desktopTextExtraSmall(context).copyWith(
+                            color: Theme.of(context)
+                                .extension<StackColors>()!
+                                .textFieldActiveText,
+                            height: 1.8,
+                          )
+                        : STextStyles.field(context),
                     focusNode: noteFieldFocusNode,
-                    decoration: standardInputDecoration(
-                      "Note",
-                      noteFieldFocusNode,
-                      context,
-                      desktopMed: isDesktop,
-                    ).copyWith(
-                      contentPadding:
-                          isDesktop
+                    decoration:
+                        standardInputDecoration(
+                          "Note",
+                          noteFieldFocusNode,
+                          context,
+                          desktopMed: isDesktop,
+                        ).copyWith(
+                          contentPadding: isDesktop
                               ? const EdgeInsets.only(
-                                left: 16,
-                                top: 11,
-                                bottom: 12,
-                                right: 5,
-                              )
+                                  left: 16,
+                                  top: 11,
+                                  bottom: 12,
+                                  right: 5,
+                                )
                               : null,
-                      suffixIcon:
-                          _noteController.text.isNotEmpty
+                          suffixIcon: _noteController.text.isNotEmpty
                               ? Padding(
-                                padding: const EdgeInsets.only(right: 0),
-                                child: UnconstrainedBox(
-                                  child: Row(
-                                    children: [
-                                      TextFieldIconButton(
-                                        child: const XIcon(),
-                                        onTap: () async {
-                                          setState(() {
-                                            _noteController.text = "";
-                                          });
-                                        },
-                                      ),
-                                    ],
+                                  padding: const EdgeInsets.only(right: 0),
+                                  child: UnconstrainedBox(
+                                    child: Row(
+                                      children: [
+                                        TextFieldIconButton(
+                                          child: const XIcon(),
+                                          onTap: () async {
+                                            setState(() {
+                                              _noteController.text = "";
+                                            });
+                                          },
+                                        ),
+                                      ],
+                                    ),
                                   ),
-                                ),
-                              )
+                                )
                               : null,
-                    ),
+                        ),
                   ),
                 ),
               ),
-              // if (!isDesktop)
-              const Spacer(),
+              if (!isDesktop) const Spacer(),
+              if (isDesktop) const SizedBox(height: 12),
               if (isDesktop)
                 Padding(
                   padding: const EdgeInsets.all(32),
@@ -198,7 +195,7 @@ class _EditNoteViewState extends ConsumerState<EditNoteView> {
                                 ),
                           );
 
-                      if (mounted) {
+                      if (context.mounted) {
                         Navigator.of(context).pop();
                       }
                     },
@@ -217,7 +214,7 @@ class _EditNoteViewState extends ConsumerState<EditNoteView> {
                                 value: _noteController.text,
                               ),
                         );
-                    if (mounted) {
+                    if (context.mounted) {
                       Navigator.of(context).pop();
                     }
                   },
@@ -242,7 +239,9 @@ class MobileEditNoteScaffold extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     if (Util.isDesktop) {
-      return child;
+      // Desktop callers host this view in a DesktopDialog of fixed height,
+      // which a multi-line note field can exceed.
+      return SingleChildScrollView(child: child);
     } else {
       return SafeArea(
         child: Padding(

### test/pages/edit_note_views_test.dart
@@ -0,0 +1,285 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:stackwallet/db/isar/main_db.dart';
+import 'package:stackwallet/models/isar/models/transaction_note.dart';
+import 'package:stackwallet/models/isar/stack_theme.dart';
+import 'package:stackwallet/pages/exchange_view/edit_trade_note_view.dart';
+import 'package:stackwallet/pages/wallet_view/transaction_views/edit_note_view.dart';
+import 'package:stackwallet/providers/db/main_db_provider.dart';
+import 'package:stackwallet/providers/exchange/trade_note_service_provider.dart';
+import 'package:stackwallet/providers/wallet/transaction_note_provider.dart';
+import 'package:stackwallet/services/trade_notes_service.dart';
+import 'package:stackwallet/themes/stack_colors.dart';
+import 'package:stackwallet/themes/theme_service.dart';
+import 'package:stackwallet/utilities/util.dart';
+import 'package:stackwallet/widgets/desktop/desktop_dialog.dart';
+
+import '../sample_data/theme_json.dart';
+
+void main() {
+  late double? originalScreenWidth;
+
+  setUp(() {
+    originalScreenWidth = Util.screenWidth;
+    Util.screenWidth = 400;
+  });
+
+  tearDown(() {
+    Util.screenWidth = originalScreenWidth;
+  });
+
+  ThemeData buildTheme() {
+    return ThemeData(
+      extensions: [
+        StackColors.fromStackColorTheme(
+          StackTheme.fromJson(json: lightThemeJsonMap),
+        ),
+      ],
+    );
+  }
+
+  ThemeService buildThemeService() =>
+      _TestThemeService(StackTheme.fromJson(json: lightThemeJsonMap));
+
+  testWidgets('trade notes accept and save multiple lines', (tester) async {
+    final service = _RecordingTradeNotesService();
+
+    await tester.pumpWidget(
+      ProviderScope(
+        overrides: [
+          pThemeService.overrideWithValue(buildThemeService()),
+          tradeNoteServiceProvider.overrideWithValue(service),
+        ],
+        child: MaterialApp(
+          theme: buildTheme(),
+          home: const EditTradeNoteView(tradeId: 'trade-id', note: ''),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    final field = tester.widget<TextField>(find.byType(TextField));
+    expect(field.minLines, 3);
+    expect(field.maxLines, 6);
+    expect(field.keyboardType, TextInputType.multiline);
+    expect(field.textInputAction, TextInputAction.newline);
+
+    await tester.enterText(find.byType(TextField), 'first line\nsecond line');
+    await tester.tap(find.text('Save'));
+    await tester.pump();
+
+    expect(service.savedTradeId, 'trade-id');
+    expect(service.savedNote, 'first line\nsecond line');
+  });
+
+  testWidgets('transaction notes accept and save multiple lines', (
+    tester,
+  ) async {
+    final db = _RecordingMainDB();
+
+    await tester.pumpWidget(
+      ProviderScope(
+        overrides: [
+          pThemeService.overrideWithValue(buildThemeService()),
+          mainDBProvider.overrideWithValue(db),
+          pTransactionNote.overrideWithProvider(
+            (key) => Provider((ref) => null),
+          ),
+        ],
+        child: MaterialApp(
+          theme: buildTheme(),
+          home: const EditNoteView(txid: 'txid', walletId: 'wallet-id'),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    final field = tester.widget<TextField>(find.byType(TextField));
+    expect(field.minLines, 3);
+    expect(field.maxLines, 6);
+    expect(field.keyboardType, TextInputType.multiline);
+    expect(field.textInputAction, TextInputAction.newline);
+
+    await tester.enterText(find.byType(TextField), 'first line\nsecond line');
+    await tester.tap(find.text('Save'));
+    await tester.pump();
+
+    final saved = db.savedNote!;
+    expect(saved.walletId, 'wallet-id');
+    expect(saved.txid, 'txid');
+    expect(saved.value, 'first line\nsecond line');
+  });
+
+  // Desktop opens both editors inside a fixed size DesktopDialog; every call
+  // site uses 580x360.
+  Future<void> pumpInDesktopDialog(
+    WidgetTester tester, {
+    required List<Override> overrides,
+    required Widget child,
+  }) async {
+    Util.screenWidth = null;
+    await tester.pumpWidget(
+      ProviderScope(
+        overrides: overrides,
+        child: MaterialApp(
+          theme: buildTheme(),
+          home: Scaffold(
+            body: Builder(
+              builder: (context) => TextButton(
+                onPressed: () => showDialog<void>(
+                  context: context,
+                  builder: (_) => DesktopDialog(
+                    maxWidth: 580,
+                    maxHeight: 360,
+                    child: child,
+                  ),
+                ),
+                child: const Text('open'),
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+    await tester.tap(find.text('open'));
+    await tester.pumpAndSettle();
+  }
+
+  /// A note taller than the dialog must scroll inside it: no overflow, and Save
+  /// still painted within the dialog card.
+  Future<void> expectNoteFitsDialog(WidgetTester tester, String note) async {
+    await tester.enterText(find.byType(TextField), note);
+    await tester.pumpAndSettle();
+    expect(tester.takeException(), isNull);
+
+    final card = tester.getRect(
+      find
+          .descendant(
+            of: find.byType(DesktopDialog),
+            matching: find.byType(Material),
+          )
+          .first,
+    );
+    final scrollable = tester.state<ScrollableState>(
+      find
+          .descendant(
+            of: find.byType(DesktopDialog),
+            matching: find.byType(Scrollable),
+          )
+          .first,
+    );
+    scrollable.position.jumpTo(scrollable.position.maxScrollExtent);
+    await tester.pumpAndSettle();
+
+    final save = tester.getRect(find.text('Save'));
+    expect(save.top, greaterThanOrEqualTo(card.top));
+    expect(save.bottom, lessThanOrEqualTo(card.bottom));
+  }
+
+  for (final lines in [1, 3, 4, 6]) {
+    testWidgets('desktop transaction note editor fits $lines line(s)', (
+      tester,
+    ) async {
+      await pumpInDesktopDialog(
+        tester,
+        overrides: [
+          pThemeService.overrideWithValue(buildThemeService()),
+          mainDBProvider.overrideWithValue(_RecordingMainDB()),
+          pTransactionNote.overrideWithProvider(
+            (key) => Provider((ref) => null),
+          ),
+        ],
+        child: const EditNoteView(txid: 'txid', walletId: 'wallet-id'),
+      );
+
+      await expectNoteFitsDialog(
+        tester,
+        List.generate(lines, (i) => 'line $i').join('\n'),
+      );
+    });
+  }
+
+  testWidgets('desktop transaction note editor fits a wrapped paragraph', (
+    tester,
+  ) async {
+    await pumpInDesktopDialog(
+      tester,
+      overrides: [
+        pThemeService.overrideWithValue(buildThemeService()),
+        mainDBProvider.overrideWithValue(_RecordingMainDB()),
+        pTransactionNote.overrideWithProvider((key) => Provider((ref) => null)),
+      ],
+      child: const EditNoteView(txid: 'txid', walletId: 'wallet-id'),
+    );
+
+    // No newline at all: soft wrapping alone grows the field to maxLines.
+    await expectNoteFitsDialog(tester, List.filled(80, 'word').join(' '));
+  });
+
+  testWidgets('desktop transaction note editor fits a very long note', (
+    tester,
+  ) async {
+    await pumpInDesktopDialog(
+      tester,
+      overrides: [
+        pThemeService.overrideWithValue(buildThemeService()),
+        mainDBProvider.overrideWithValue(_RecordingMainDB()),
+        pTransactionNote.overrideWithProvider((key) => Provider((ref) => null)),
+      ],
+      child: const EditNoteView(txid: 'txid', walletId: 'wallet-id'),
+    );
+
+    await expectNoteFitsDialog(
+      tester,
+      List.generate(400, (i) => 'line $i ${'x' * 40}').join('\n'),
+    );
+  });
+
+  testWidgets('desktop trade note editor fits six lines', (tester) async {
+    await pumpInDesktopDialog(
+      tester,
+      overrides: [
+        pThemeService.overrideWithValue(buildThemeService()),
+        tradeNoteServiceProvider.overrideWithValue(
+          _RecordingTradeNotesService(),
+        ),
+      ],
+      child: const EditTradeNoteView(tradeId: 'trade-id', note: ''),
+    );
+
+    await expectNoteFitsDialog(
+      tester,
+      List.generate(6, (i) => 'line $i').join('\n'),
+    );
+  });
+}
+
+class _TestThemeService extends Fake implements ThemeService {
+  _TestThemeService(this.theme);
+
+  final StackTheme theme;
+
+  @override
+  StackTheme? getTheme({required String themeId}) => theme;
+}
+
+class _RecordingMainDB extends Fake implements MainDB {
+  TransactionNote? savedNote;
+
+  @override
+  Future<void> putTransactionNote(TransactionNote transactionNote) async {
+    savedNote = transactionNote;
+  }
+}
+
+class _RecordingTradeNotesService extends TradeNotesService {
+  String? savedTradeId;
+  String? savedNote;
+
+  @override
+  Future<void> set({required String tradeId, required String note}) async {
+    savedTradeId = tradeId;
+    savedNote = note;
+  }
+}