feat(train): Maps shows every route on the map, above the list or beside it (ADR 0030, D60)

The instance's map with every route drawn, fitted to them all, a route
tapped opening its planner. On phones the map stands above the list;
from expanded windows on the two are panes side by side, as Material's
list-detail layout. Without a route to draw, the list alone.

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

apps/train/halkyon_train_flutter/lib/src/feature/route/widget/routes_map.dart

@@ -0,0 +1,108 @@
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:flutter_map/flutter_map.dart';
+import 'package:halkyon_app/halkyon_app.dart';
+import 'package:halkyon_train_client/halkyon_train_client.dart' show MapSource;
+import 'package:halkyon_train_flutter/src/app/train_dependencies.dart';
+import 'package:halkyon_train_flutter/src/feature/map/widget/map_tiles.dart';
+import 'package:halkyon_train_flutter/src/feature/route/bloc/routes_cubit.dart';
+import 'package:halkyon_train_flutter/src/feature/route/model/route.dart';
+import 'package:halkyon_train_flutter/src/feature/route/widget/route_screen.dart';
+import 'package:halkyon_ui/halkyon_ui.dart';
+import 'package:latlong2/latlong.dart';
+import 'package:material_ui/material_ui.dart';
+
+/// The person's routes with a way to draw, each its planned way, else its
+/// waypoints, by its id.
+List<({String id, RouteContent content, List<LatLng> points})> drawnRoutes(
+  RoutesState state,
+) => [
+  for (final route in state.visible)
+    if (route.content case final content?)
+      if (content.planned?.points ?? content.waypoints case final points
+          when points.length > 1)
+        (id: route.id, content: content, points: points),
+];
+
+/// Every route on the instance's map, as the Maps tab shows them (ADR 0030,
+/// D60): the camera fitting them all, one tapped opening its planner; the
+/// lines without tiles where the instance's map source can't be asked.
+class const RoutesMap({super.key}) extends StatefulWidget {
+  @override
+  State<RoutesMap> createState() => _RoutesMapState();
+}
+
+class _RoutesMapState() extends State<RoutesMap> {
+  late final Future<MapSource?> _source = PersonScope.of<TrainPerson>(
+    context,
+  ).maps.source();
+
+  /// Where a line was last hit, so that a tap knows which.
+  final _hit = LayerHitNotifier<Object>(null);
+
+  @override
+  void dispose() {
+    _hit.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final train = PersonScope.of<TrainPerson>(context);
+    final routes = drawnRoutes(context.watch<RoutesCubit>().state);
+    final all = [for (final route in routes) ...route.points];
+    return FutureBuilder(
+      future: _source,
+      builder: (context, snapshot) => FlutterMap(
+        // Fitted again as routes come and go.
+        key: ValueKey({for (final route in routes) route.id}.join(' ')),
+        options: MapOptions(
+          maxZoom: mapMaxZoom,
+          initialCameraFit: CameraFit.coordinates(
+            coordinates: all,
+            padding: const EdgeInsets.all(32),
+            maxZoom: 16,
+          ),
+          interactionOptions: const InteractionOptions(
+            flags: InteractiveFlag.all & ~InteractiveFlag.rotate,
+          ),
+        ),
+        children: [
+          if (snapshot.data case final source?) train.mapTiles(source),
+          GestureDetector(
+            onTap: () {
+              final id = _hit.value?.hitValues.firstOrNull;
+              if (id == null) {
+                return;
+              }
+              for (final route in routes) {
+                if (route.id == id) {
+                  openRouteScreen(context, route.content, id: route.id);
+                }
+              }
+            },
+            child: PolylineLayer(
+              hitNotifier: _hit,
+              // A finger's width: the lines are 4 wide.
+              minimumHitbox: 20,
+              polylines: [
+                for (final route in routes)
+                  Polyline<Object>(
+                    points: route.points,
+                    hitValue: route.id,
+                    // Cobalt in either theme: the map's colours are the
+                    // source's, not the app's.
+                    color: PaletteColor.cobalt.background,
+                    strokeWidth: 4,
+                  ),
+              ],
+            ),
+          ),
+          if (snapshot.data case final source?)
+            RichAttributionWidget(
+              attributions: [TextSourceAttribution(source.attribution)],
+            ),
+        ],
+      ),
+    );
+  }
+}

apps/train/halkyon_train_flutter/lib/src/tabs/maps_tab.dart

@@ -1,13 +1,60 @@
+import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:halkyon_train_flutter/l10n/app_localizations.dart';
+import 'package:halkyon_train_flutter/src/feature/route/bloc/routes_cubit.dart';
 import 'package:halkyon_train_flutter/src/feature/route/widget/routes_list.dart';
+import 'package:halkyon_train_flutter/src/feature/route/widget/routes_map.dart';
 import 'package:halkyon_train_flutter/src/tabs/tab_screen.dart';
+import 'package:halkyon_ui/halkyon_ui.dart';
 import 'package:material_ui/material_ui.dart';
 
-/// Maps (ADR 0030, D60): the person's routes (D44), and planning another.
+/// Maps (ADR 0030, D60): the person's routes (D44) on a map and in a list,
+/// and planning another. Below expanded windows the map stands above the
+/// list; from there on they are two panes, the list beside the map, as
+/// Material's list–detail layout; without a route to draw, the list alone.
 class const MapsTab({super.key}) extends StatelessWidget {
+  static const double _listWidth = 400;
+
   @override
-  Widget build(BuildContext context) => TabScreen(
-    title: AppLocalizations.of(context).shellTabMaps,
-    body: const RoutesList(),
-  );
+  Widget build(BuildContext context) {
+    final drawn = context.select<RoutesCubit, bool>(
+      (cubit) => drawnRoutes(cubit.state).isNotEmpty,
+    );
+    final map = Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 12),
+      child: ClipRRect(
+        borderRadius: BorderRadius.circular(16),
+        child: const RoutesMap(),
+      ),
+    );
+    return TabScreen(
+      title: AppLocalizations.of(context).shellTabMaps,
+      body: switch ((drawn, context.windowSize)) {
+        (false, _) => const RoutesList(),
+        (true, WindowSize.compact || WindowSize.medium) => Column(
+          children: [
+            SizedBox(
+              height: (MediaQuery.sizeOf(context).height * 0.4).clamp(
+                200,
+                360,
+              ),
+              child: map,
+            ),
+            const Expanded(child: RoutesList()),
+          ],
+        ),
+        (true, _) => Row(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            const SizedBox(width: _listWidth, child: RoutesList()),
+            Expanded(
+              child: Padding(
+                padding: const EdgeInsets.only(bottom: 12),
+                child: map,
+              ),
+            ),
+          ],
+        ),
+      },
+    );
+  }
 }