Remove NavigatableSource

And `MappedNavigatableSource`, as it's just too easy to mistakenly create new instances of such classes over and over (in `build`), instead of using retained instances

The downside of this might of course be that interacting with "child navigators" from the parent will now become harder, as you can not just call instance methods if you had a reference. (Though this can be fixed by using controllers, ref-like access to the state, or similar patterns.)

example/lib/main.dart

@@ -34,8 +34,8 @@ class MyHomePage extends StatefulWidget {
 class _MyHomePageState extends State<MyHomePage> {
   @override
   Widget build(BuildContext context) {
-    return DeclarativeNavigator.managing(
-      navigatorFactory: () => ExampleSelectionNavigator(),
+    return DeclarativeNavigator(
+      navigator: ExampleSelectionNavigator(),
     );
   }
 }

example/lib/src/examples/dynamic_pop_navigator.dart

@@ -2,34 +2,36 @@ import 'package:fdr/fdr.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
-class DynamicPopNavigator extends MappedNavigatableSource<
-    (
-      bool /* shows child */,
-      bool /* can pop */,
-    )> {
-  DynamicPopNavigator() : super(initialState: (true, false));
+class DynamicPopNavigator extends StatefulNavigator {
+  @override
+  StatefulNavigatorState<DynamicPopNavigator> createState() =>
+      _DynamicPopNavigatorState();
+}
+
+class _DynamicPopNavigatorState
+    extends StatefulNavigatorState<DynamicPopNavigator> {
+  bool showChild = true;
+  bool canPop = false;
 
   @override
   List<DeclarativeNavigatable> build() {
-    final canPop = state.$2;
-
     return [
       Scaffold(
         appBar: AppBar(
           title: const Text('Dynamic pop parent'),
         ),
         body: Center(
           child: FilledButton(
-            onPressed: () => state = (true, false),
+            onPressed: () => setState(() => showChild = true),
             child: const Text('Open child page'),
           ),
         ),
       ).page(onPop: null),
-      if (state.$1)
+      if (showChild)
         PopToggle(
           value: canPop,
-          onChange: (v) => state = (true, v),
-        ).page(onPop: canPop ? () => state = (false, false) : null),
+          onChange: (v) => setState(() => canPop = v),
+        ).page(onPop: canPop ? () => setState(() => showChild = false) : null),
     ];
   }
 }

example/lib/src/examples/example_selection_navigator.dart

@@ -1,30 +1,24 @@
 import 'package:fdr/fdr.dart';
 import 'package:fdr_example/src/examples/dynamic_pop_navigator.dart';
-import 'package:fdr_example/src/examples/hot_reloadable_mapped_navigator.dart';
 import 'package:fdr_example/src/examples/hot_reloadable_stateful_navigator.dart';
 import 'package:fdr_example/src/examples/hot_reloadable_stateless_navigator.dart';
 import 'package:fdr_example/src/examples/list_detail_navigator.dart';
 import 'package:fdr_example/src/examples/overlay_portal_navigator.dart';
 import 'package:flutter/cupertino.dart';
 
-class ExampleSelectionNavigator
-    extends MappedNavigatableSource<DeclarativeNavigatable?> {
-  ExampleSelectionNavigator() : super(initialState: null);
-
-  // Manage state, such that any previous value is always cleaned up
+class ExampleSelectionNavigator extends StatefulNavigator {
   @override
-  set state(DeclarativeNavigatable? newState) {
-    final state = this.state;
-    if (state is DisposableNavigatable) {
-      state.dispose();
-    }
+  StatefulNavigatorState<ExampleSelectionNavigator> createState() =>
+      _ExampleSelectionNavigatorState();
+}
 
-    super.state = newState;
-  }
+class _ExampleSelectionNavigatorState
+    extends StatefulNavigatorState<ExampleSelectionNavigator> {
+  DeclarativeNavigatable? child;
 
   @override
   List<DeclarativeNavigatable> build() {
-    final state = this.state;
+    final child = this.child;
 
     return [
       ExampleSelectionPage(
@@ -33,22 +27,16 @@ class ExampleSelectionNavigator
           'Dynamic back behavior': () => DynamicPopNavigator(),
           'Stateful Navigator': () => HotReloadableStatefulNavigator(),
           'Stateless Navigator': () => HotReloadableStatelessNavigator(),
-          'Mapped Navigator': () => HotReloadableMappedNavigator(),
           'Overlay Portal': () => OverlayPortalNavigator(),
         },
-        onExampleSelect: (exampleFactory) => this.state = exampleFactory(),
+        onExampleSelect: (exampleFactory) => setState(
+          () => this.child = exampleFactory(),
+        ),
       ).page(onPop: null),
-      if (state != null) state.poppable(onPop: () => this.state = null)
+      if (child != null)
+        child.poppable(onPop: () => setState(() => this.child = null)),
     ];
   }
-
-  @override
-  void dispose() {
-    // clean up any potentially created navigators
-    state = null;
-
-    super.dispose();
-  }
 }
 
 class ExampleSelectionPage extends StatelessWidget {

example/lib/src/examples/list_detail_navigator.dart

@@ -2,24 +2,36 @@ import 'package:fdr/fdr.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
-class ListDetailNavigator extends MappedNavigatableSource<int?> {
-  ListDetailNavigator() : super(initialState: null);
+class ListDetailNavigator extends StatefulNavigator {
+  ListDetailNavigator();
+
+  @override
+  StatefulNavigatorState<ListDetailNavigator> createState() =>
+      _ListDetailNavigatorState();
+}
+
+class _ListDetailNavigatorState
+    extends StatefulNavigatorState<ListDetailNavigator> {
+  int? selectedNumber;
 
   @override
   List<DeclarativeNavigatable> build() {
-    final state = this.state;
+    final selectedNumber = this.selectedNumber;
+
+    clear() => setState(() => this.selectedNumber = null);
 
     return [
       NumberSelectionPage(
-        onNumberSelect: (number) => this.state = number,
+        onNumberSelect: (number) =>
+            setState(() => this.selectedNumber = number),
       ).page(onPop: null),
-      if (state != null)
-        if (state == 7)
+      if (selectedNumber != null)
+        if (selectedNumber == 7)
           LuckyNumberSevenPage(
-            onTap: () => this.state = null,
-          ).popup(onPop: () => this.state = null)
+            onTap: clear,
+          ).popup(onPop: clear)
         else
-          NumberDetailPage(number: state).page(onPop: () => this.state = null),
+          NumberDetailPage(number: selectedNumber).page(onPop: clear),
     ];
   }
 }

lib/fdr.dart

@@ -5,15 +5,12 @@ export './src/declarative_navigatable/declarative_navigatable.dart'
     show
         DeclarativeNavigatable,
         DeclarativeNavigatablePage,
-        NavigatableSource,
         PageBuilder,
         Poppable,
         StatefulNavigator,
         StatefulNavigatorState,
         DisposableNavigatable,
         PopOverwriteNavigatable;
-export './src/declarative_navigatable/mapped_navigatable_source.dart'
-    show MappedNavigatableSource;
 export './src/declarative_navigatable/stateless_navigator.dart'
     show StatelessNavigator;
 export './src/declarative_navigator.dart' show DeclarativeNavigator;

lib/src/declarative_navigatable/declarative_navigatable.dart

@@ -5,7 +5,6 @@ import 'package:flutter/widgets.dart';
 
 part 'declarative_navigatable_page.dart';
 part 'disposable_navigatable.dart';
-part 'navigatable_source.dart';
 part 'pop_overwrite_navigatable.dart';
 part 'stateful_navigator.dart';
 

lib/src/declarative_navigatable/stateful_navigator.dart

@@ -4,13 +4,11 @@ abstract class StatefulNavigator implements DeclarativeNavigatable {
   StatefulNavigatorState createState();
 }
 
-abstract class StatefulNavigatorState<T extends StatefulNavigator>
-    implements NavigatableSource {
+abstract class StatefulNavigatorState<T extends StatefulNavigator> {
   late T navigator;
 
   late final NavigatableToPageMapper _pageMapper;
 
-  @override
   ValueListenable<List<DeclarativeNavigatablePage>> get pages =>
       _pageMapper.pages;
 

lib/src/declarative_navigator.dart

@@ -9,16 +9,6 @@ class DeclarativeNavigator extends StatefulWidget {
     required this.navigator,
   });
 
-  static Widget managing({
-    Key? key,
-    required ValueGetter<DisposableNavigatable> navigatorFactory,
-  }) {
-    return _ManagingDeclarativeNavigator(
-      key: key,
-      navigatorFactory: navigatorFactory,
-    );
-  }
-
   static final _hotReload = ChangeNotifier();
   static Listenable get hotReload => _hotReload;
 
@@ -80,42 +70,3 @@ class _DeclarativeNavigatorState extends State<DeclarativeNavigator> {
     super.dispose();
   }
 }
-
-class _ManagingDeclarativeNavigator extends StatefulWidget {
-  const _ManagingDeclarativeNavigator({
-    super.key,
-    required this.navigatorFactory,
-  });
-
-  final ValueGetter<DisposableNavigatable> navigatorFactory;
-
-  @override
-  State<_ManagingDeclarativeNavigator> createState() =>
-      __ManagingDeclarativeNavigatorState();
-}
-
-class __ManagingDeclarativeNavigatorState
-    extends State<_ManagingDeclarativeNavigator> {
-  late final DisposableNavigatable navigator;
-
-  @override
-  void initState() {
-    super.initState();
-
-    navigator = widget.navigatorFactory();
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return DeclarativeNavigator(
-      navigator: navigator,
-    );
-  }
-
-  @override
-  void dispose() {
-    navigator.dispose();
-
-    super.dispose();
-  }
-}