adding packages

2026-01-15 14:38:46 -08:00
parent ef86e3ab6a
commit 6869cf47e5
5253 changed files with 726695 additions and 34 deletions
@@ -0,0 +1,179 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+
+import 'package:undo/undo.dart';
+
+void main() => runApp(MyApp());
+
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      theme: ThemeData.light(),
+      darkTheme: ThemeData.dark(),
+      debugShowCheckedModeBanner: false,
+      home: HomeScreen(),
+    );
+  }
+}
+
+class HomeScreen extends StatefulWidget {
+  @override
+  _HomeScreenState createState() => _HomeScreenState();
+}
+
+class _HomeScreenState extends State<HomeScreen> {
+  late TrackedStreamController<int> _controller = TrackedStreamController(
+    0,
+  );
+
+  @override
+  Widget build(BuildContext context) {
+    return StreamBuilder<int>(
+      initialData: 0,
+      stream: _controller.stream,
+      builder: (context, snapshot) {
+        final count = snapshot.data!;
+        return Scaffold(
+          appBar: AppBar(
+            title: Text('Undo/Redo Example'),
+          ),
+          body: Center(
+            child: Text('Count: $count'),
+          ),
+          bottomNavigationBar: BottomAppBar(
+            child: Row(
+              children: <Widget>[
+                IconButton(
+                  icon: Icon(Icons.arrow_back),
+                  onPressed: !_controller.canUndo
+                      ? null
+                      : () {
+                          if (mounted)
+                            setState(() {
+                              _controller.undo();
+                            });
+                        },
+                ),
+                IconButton(
+                  icon: Icon(Icons.arrow_forward),
+                  onPressed: !_controller.canRedo
+                      ? null
+                      : () {
+                          if (mounted)
+                            setState(() {
+                              _controller.redo();
+                            });
+                        },
+                ),
+              ],
+            ),
+          ),
+          floatingActionButtonLocation: FloatingActionButtonLocation.endDocked,
+          floatingActionButton: FloatingActionButton(
+            heroTag: ValueKey('add_button'),
+            child: Icon(Icons.add),
+            onPressed: () {
+              _controller.add(count + 1);
+            },
+          ),
+        );
+      },
+    );
+  }
+}
+
+class TrackedStreamController<T> implements StreamController<T> {
+  late SimpleStack<T> _simpleStack;
+  late StreamController<T> _streamController;
+
+  TrackedStreamController(
+    T value, {
+    int? limit,
+    this.onCancel,
+    this.onListen,
+    this.onPause,
+    this.onResume,
+    bool sync = false,
+  }) {
+    _streamController = StreamController<T>(
+      onCancel: onCancel,
+      onListen: onListen,
+      onPause: onPause,
+      onResume: onResume,
+      sync: sync,
+    );
+    _simpleStack = SimpleStack<T>(value, limit: limit, onUpdate: (newVal) {
+      _streamController.add(newVal);
+    });
+  }
+
+  Stream<T> get stream => _streamController.stream;
+  void add(T value) => _simpleStack.modify(value);
+
+  bool get canUndo => _simpleStack.canUndo;
+  bool get canRedo => _simpleStack.canRedo;
+  void redo() => _simpleStack.redo();
+  void undo() => _simpleStack.undo();
+
+  @override
+  final FutureOr<void> Function()? onCancel;
+
+  @override
+  final void Function()? onListen;
+
+  @override
+  final void Function()? onPause;
+
+  @override
+  final void Function()? onResume;
+
+  @override
+  void addError(Object error, [StackTrace? stackTrace]) {
+    _streamController.addError(error, stackTrace);
+  }
+
+  @override
+  Future addStream(Stream<T> source, {bool? cancelOnError}) {
+    return _streamController.addStream(source, cancelOnError: cancelOnError);
+  }
+
+  @override
+  Future get done => _streamController.done;
+
+  @override
+  bool get hasListener => _streamController.hasListener;
+
+  @override
+  bool get isClosed => _streamController.isClosed;
+
+  @override
+  bool get isPaused => _streamController.isPaused;
+
+  @override
+  StreamSink<T> get sink => _streamController.sink;
+
+  @override
+  Future close() => _streamController.close();
+
+  @override
+  set onCancel(FutureOr<void> Function()? _onCancel) {
+    onCancel = _onCancel!;
+  }
+
+  @override
+  set onListen(void Function()? _onListen) {
+    onListen = _onListen!;
+  }
+
+  @override
+  set onPause(void Function()? _onPause) {
+    onPause = _onPause!;
+  }
+
+  @override
+  set onResume(void Function()? _onResume) {
+    onResume = _onResume!;
+  }
+}