fix(map): a region is picked on a screen of its own, and a country's map offered once it is picked

The composer showed the map inside its scrolling page, so zooming and
scrolling fought over the wheel. A map question's answer is now a field
that opens the map in the whole window, as a studyset's description is
written, with Save in the app bar; nothing scrolls there, so the wheel
alone zooms. The Prefectures chip stood beside East Asia's countries
before Japan was picked; it now shows once Japan, or a prefecture, is.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMm7usAo6q9ZZRoPkWjoxi
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

halkyon_learn_flutter/test/feature/card/widget/card_composer_test.dart

@@ -6,6 +6,7 @@ import 'package:halkyon_learn_flutter/src/core/content/content_blocks.dart';
 import 'package:halkyon_learn_flutter/src/core/content/rich_content.dart';
 import 'package:halkyon_learn_flutter/src/core/editor/rich_content_editor.dart';
 import 'package:halkyon_learn_flutter/src/core/router/route_paths.dart';
+import 'package:halkyon_learn_flutter/src/core/widget/chevron_field.dart';
 import 'package:halkyon_learn_flutter/src/feature/card/data/card_payload.dart';
 import 'package:halkyon_learn_flutter/src/feature/card/data/card_repository.dart';
 import 'package:halkyon_learn_flutter/src/feature/card/model/card_content.dart';
@@ -122,6 +123,12 @@ void main() {
     await settle(tester);
   }
 
+  /// Opens the map from a map question's answer.
+  Future<void> pickOnMap(WidgetTester tester) async {
+    await tester.tap(find.byType(ChevronField));
+    await settle(tester);
+  }
+
   /// Chooses [item] of the card's ⋮ menu.
   Future<void> action(WidgetTester tester, String item) async {
     await tester.tap(find.byTooltip('More actions'));
@@ -637,19 +644,32 @@ void main() {
     expect(saved.back, RichContent.empty());
   });
 
-  testWidgets('a map question takes the region tapped as its answer', (
-    tester,
-  ) async {
+  testWidgets('a map question takes the region tapped on a screen of its '
+      'own, where nothing scrolls, as its answer once saved', (tester) async {
     await cards.create('japanese', card('Where is Tokyo?', 'east'));
     await showStudyset(tester, maps: await loadedMaps(tester));
     await open(tester, 'Where is Tokyo?');
 
     await tester.tap(find.text('Map'));
     await settle(tester);
+    expect(find.byType(RegionMap), findsNothing);
+    await pickOnMap(tester);
     expect(find.text('No region picked yet'), findsOneWidget);
+    expect(
+      find.ancestor(
+        of: find.byType(RegionMap),
+        matching: find.byType(Scrollable),
+      ),
+      findsNothing,
+    );
+    expect(tester.widget<RegionMap>(find.byType(RegionMap)).wheelZooms, true);
     tester.widget<RegionMap>(find.byType(RegionMap)).onRegionTapped!('JP-13');
     await settle(tester);
     expect(find.text('Tokyo · 東京都'), findsOneWidget);
+    await tester.tap(find.widgetWithText(FilledButton, 'Save'));
+    await settle(tester);
+    expect(find.byType(RegionMap), findsNothing);
+    expect(find.text('Tokyo · 東京都'), findsOneWidget);
     await tester.tap(find.byType(BackButton));
     await settle(tester);
 
@@ -676,10 +696,13 @@ void main() {
     await tester.tap(find.text('Map'));
     await settle(tester);
     expect(find.text('Countries of the world'), findsNothing);
+    await pickOnMap(tester);
     tester.widget<RegionMap>(find.byType(RegionMap)).onRegionTapped!('JP-13');
     await settle(tester);
     tester.widget<RegionMap>(find.byType(RegionMap)).onRegionTapped!('CY');
     await settle(tester);
+    await tester.tap(find.widgetWithText(FilledButton, 'Save'));
+    await settle(tester);
     // Beside the app's language, the studyset's: Japanese.
     expect(find.text('Cyprus · キプロス'), findsOneWidget);
     await tester.tap(find.byType(BackButton));
@@ -720,6 +743,7 @@ void main() {
 
     await tester.tap(find.text('Map'));
     await settle(tester);
+    await pickOnMap(tester);
 
     expect(tester.widget<RegionMap>(find.byType(RegionMap)).around, {
       'JP-13',
@@ -731,4 +755,23 @@ void main() {
       findsOneWidget,
     );
   });
+
+  testWidgets('leaving the map without saving keeps the answer', (
+    tester,
+  ) async {
+    await cards.create('japanese', card('Where is Tokyo?', 'east'));
+    await showStudyset(tester, maps: await loadedMaps(tester));
+    await open(tester, 'Where is Tokyo?');
+    await tester.tap(find.text('Map'));
+    await settle(tester);
+
+    await pickOnMap(tester);
+    tester.widget<RegionMap>(find.byType(RegionMap)).onRegionTapped!('JP-13');
+    await settle(tester);
+    await tester.tap(find.byType(CloseButton));
+    await settle(tester);
+
+    expect(find.byType(RegionMap), findsNothing);
+    expect(find.text('Tap to pick the region on the map'), findsOneWidget);
+  });
 }

halkyon_learn_flutter/test/feature/geo_map/widget/region_map_test.dart

@@ -19,7 +19,7 @@ void main() {
   });
 
   /// Shows the maps at a phone's size, anew unless [key] is the one shown;
-  /// what is picked lands in the list.
+  /// what is picked lands in the list, and shows as picked.
   Future<List<String>> show(
     WidgetTester tester, {
     Key? key,
@@ -34,6 +34,7 @@ void main() {
       ..devicePixelRatio = 1;
     addTearDown(tester.view.reset);
     final picked = <String>[];
+    final shown = key ?? UniqueKey();
     await tester.pumpWidget(
       MaterialApp(
         theme: appTheme(Brightness.light),
@@ -42,14 +43,19 @@ void main() {
         home: Scaffold(
           body: Padding(
             padding: const EdgeInsets.all(16),
-            child: RegionMap(
-              key: key ?? UniqueKey(),
-              atlas: atlas,
-              countryTaps: countryTaps,
-              around: around,
-              right: right,
-              wrong: wrong,
-              onRegionTapped: readOnly ? null : picked.add,
+            child: StatefulBuilder(
+              builder: (context, setState) => RegionMap(
+                key: shown,
+                atlas: atlas,
+                countryTaps: countryTaps,
+                around: around,
+                selected: picked.lastOrNull,
+                right: right,
+                wrong: wrong,
+                onRegionTapped: readOnly
+                    ? null
+                    : (code) => setState(() => picked.add(code)),
+              ),
             ),
           ),
         ),
@@ -96,11 +102,12 @@ void main() {
 
   const tokyo = (139.69, 35.69);
 
-  testWidgets('Japan is picked in East Asia, and a chip opens its '
-      'prefectures in layers; Back goes up one', (tester) async {
+  testWidgets('Japan is picked in East Asia, and once it is, a chip opens '
+      'its prefectures in layers; Back goes up one', (tester) async {
     final picked = await show(tester);
 
     await choose(tester, 'East Asia');
+    expect(chip('Prefectures'), findsNothing);
     await tapAt(tester, tokyo);
     expect(picked, ['JP']);
 
@@ -130,6 +137,11 @@ void main() {
     await tester.tap(back('East Asia'));
     await tester.pumpAndSettle();
     expect(find.text('East Asia'), findsOneWidget);
+    // Osaka is within Japan; Seoul isn't.
+    expect(chip('Prefectures'), findsOneWidget);
+    await tapAt(tester, (126.98, 37.57));
+    expect(picked.last, 'KR');
+    expect(chip('Prefectures'), findsNothing);
     await tester.tap(back('World'));
     await tester.pumpAndSettle();
     expect(chip('Europe'), findsOneWidget);