WIP: integration with ledger

frontend/pshared/lib/provider/payment/source.dart

@@ -0,0 +1,33 @@
+import 'package:flutter/foundation.dart';
+
+import 'package:pshared/models/payment/source.dart';
+import 'package:pshared/provider/ledger.dart';
+import 'package:pshared/provider/payment/wallets.dart';
+
+class PaymentSourceProvider extends ChangeNotifier {
+  List<PaymentSource> _sources = const [];
+
+  List<PaymentSource> get sources => _sources;
+
+  void update(
+    WalletsProvider walletsProvider,
+    LedgerAccountsProvider ledgerProvider,
+  ) {
+    final nextSources = <PaymentSource>[
+      ...walletsProvider.wallets.map(PaymentSource.wallet),
+      ...ledgerProvider.accounts.map(PaymentSource.ledger),
+    ];
+
+    final currentKeys = _sources
+        .map((source) => source.key)
+        .toList(growable: false);
+    final nextKeys = nextSources
+        .map((source) => source.key)
+        .toList(growable: false);
+
+    if (listEquals(currentKeys, nextKeys)) return;
+
+    _sources = nextSources;
+    notifyListeners();
+  }
+}