diff --git a/CHANGELOG.md b/CHANGELOG.md
index a1a15e3..55dceb0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+## 0.24.0
+- Add state pattern: State Manipulator.
+
 ## 0.23.14
 - Replace web renderer html to canvakit (deploy_flutter_demo.dart).
 
diff --git a/README.md b/README.md
index 5c6a719..bca5237 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ It contains **Dart** examples for all classic **GoF** design patterns.
     - [ ] **Mediator**
     - [x] **Memento** - [[Conceptual](https://github.com/RefactoringGuru/design-patterns-dart/tree/main/patterns/memento/conceptual)] [[Memento Editor](https://github.com/RefactoringGuru/design-patterns-dart/tree/main/patterns/memento/memento_editor)] 
     - [x] **Observer** - [[Open-Close Editor Events](https://github.com/RefactoringGuru/design-patterns-dart/tree/main/patterns/observer/open_close_editor_events)] [[AppObserver](https://github.com/RefactoringGuru/design-patterns-dart/tree/main/patterns/observer/app_observer)] [[Subscriber Flutter Widget](https://github.com/RefactoringGuru/design-patterns-dart/tree/main/patterns/observer/subscriber_flutter_widget)]
-    - [ ] **State**
+    - [x] **State** - [[State Manipulator](https://github.com/RefactoringGuru/design-patterns-dart/tree/main/patterns/state/manipulator_state)]
     - [ ] **Template Method**
     - [X] **Visitor**  [[Shape XML Exporter](https://github.com/RefactoringGuru/design-patterns-dart/tree/main/patterns/visitor/shapes_exporter)]
     - [X] **Strategy** [[Reservation Cargo Spaces](https://github.com/RefactoringGuru/design-patterns-dart/tree/main/patterns/strategy/reservation_cargo_spaces)]
@@ -32,8 +32,8 @@ It contains **Dart** examples for all classic **GoF** design patterns.
 
 ## Requirements
 
-The examples were written in **Dart 2.15**.
-Some complex examples require **Flutter 2.12**.
+The examples were written in **Dart 2.17**.
+Some complex examples require **Flutter 3.0.0**.
 
 ## Contributor's Guide
 
diff --git a/analysis_options.yaml b/analysis_options.yaml
index dee8927..39e5146 100644
--- a/analysis_options.yaml
+++ b/analysis_options.yaml
@@ -15,10 +15,9 @@ include: package:lints/recommended.yaml
 
 # Uncomment the following section to specify additional rules.
 
-# linter:
-#   rules:
-#     - camel_case_types
-
+linter:
+  rules:
+    library_private_types_in_public_api: false
 # analyzer:
 #   exclude:
 #     - path/to/excluded/files/**
diff --git a/bin/deploy_flutter_demos.dart b/bin/deploy_flutter_demos.dart
index 8721544..18b34db 100644
--- a/bin/deploy_flutter_demos.dart
+++ b/bin/deploy_flutter_demos.dart
@@ -20,9 +20,9 @@ void main() async {
   clear();
 }
 
-late final tmpDir = Directory.systemTemp.createTempSync();
-late final projectDir = thisPath(r'..\');
-late final webBuildDir = Directory(projectDir.uri.toFilePath() + r'build\web');
+ final tmpDir = Directory.systemTemp.createTempSync();
+ final projectDir = thisPath(r'..\');
+ final webBuildDir = Directory(projectDir.uri.toFilePath() + r'build\web');
 late final String originUrl;
 
 Future<void> init() async {
diff --git a/bin/main.dart b/bin/main.dart
index 1180c2d..5200232 100644
--- a/bin/main.dart
+++ b/bin/main.dart
@@ -3,6 +3,7 @@ import '../patterns/abstract_factory/tool_panel_factory/main.dart';
 import '../patterns/observer/subscriber_flutter_widget/main.dart';
 import '../patterns/adapter/flutter_adapter/main.dart';
 import '../patterns/memento/memento_editor/main.dart';
+import '../patterns/state/manipulator_state/main.dart';
 
 void main() {
   runApp(MyApp());
@@ -13,13 +14,20 @@ class MyApp extends StatelessWidget {
   Widget build(BuildContext context) {
     return MaterialApp(
       title: 'Refactoring Guru: Flutter launcher',
-      theme: ThemeData(primarySwatch: Colors.pink),
-      initialRoute: '/abstract_factory/tool_panel_factory',
+      theme: ThemeData(
+        primarySwatch: Colors.pink,
+        iconTheme: IconThemeData(
+          size: 32,
+          color: Colors.white,
+        ),
+      ),
+      initialRoute: '/state/manipulator_state',
       routes: {
         '/observer/subscriber_flutter_widget': (_) => SubscriberFlutterApp(),
         '/adapter/flutter_adapter': (_) => FlutterAdapterApp(),
         '/memento/flutter_memento_editor': (_) => FlutterMementoEditorApp(),
         '/abstract_factory/tool_panel_factory': (_) => ToolPanelFactoryApp(),
+        '/state/manipulator_state': (_) => ManipulatorStateApp(),
       },
     );
   }
diff --git a/patterns/abstract_factory/tool_panel_factory/widgets/independent/panel.dart b/patterns/abstract_factory/tool_panel_factory/widgets/independent/panel.dart
index 06343f5..c123fa8 100644
--- a/patterns/abstract_factory/tool_panel_factory/widgets/independent/panel.dart
+++ b/patterns/abstract_factory/tool_panel_factory/widgets/independent/panel.dart
@@ -2,7 +2,7 @@ import 'package:flutter/material.dart';
 
 class Panel extends StatelessWidget {
   static const thicknessWidth = 64.0;
-  static const thicknessHeight = 48.0;
+  final double thicknessHeight;
 
   final Axis direction;
   final Widget child;
@@ -11,6 +11,7 @@ class Panel extends StatelessWidget {
     Key? key,
     required this.direction,
     required this.child,
+    this.thicknessHeight = 48.0,
   }) : super(key: key);
 
   @override
diff --git a/patterns/abstract_factory/tool_panel_factory/widgets/independent/tool_button.dart b/patterns/abstract_factory/tool_panel_factory/widgets/independent/tool_button.dart
index c0a633b..441154a 100644
--- a/patterns/abstract_factory/tool_panel_factory/widgets/independent/tool_button.dart
+++ b/patterns/abstract_factory/tool_panel_factory/widgets/independent/tool_button.dart
@@ -10,7 +10,7 @@ class ToolButton extends StatelessWidget {
   const ToolButton({
     Key? key,
     required this.onTap,
-    required this.active,
+    this.active = false,
     required this.icon,
   }) : super(key: key);
 
diff --git a/patterns/abstract_factory/tool_panel_factory/widgets/property_widgets/primitive/filed_label.dart b/patterns/abstract_factory/tool_panel_factory/widgets/property_widgets/primitive/filed_label.dart
index 3371e09..7bc950d 100644
--- a/patterns/abstract_factory/tool_panel_factory/widgets/property_widgets/primitive/filed_label.dart
+++ b/patterns/abstract_factory/tool_panel_factory/widgets/property_widgets/primitive/filed_label.dart
@@ -15,7 +15,7 @@ class FieldLabel extends StatelessWidget {
     return Row(
       children: [
         SizedBox(width: 10),
-        Text(text + ':'),
+        Text('$text:'),
         SizedBox(width: 10),
         child,
         SizedBox(width: 20),
diff --git a/patterns/builder/cars/main.dart b/patterns/builder/cars/main.dart
index a7a3bc3..e1c55c5 100644
--- a/patterns/builder/cars/main.dart
+++ b/patterns/builder/cars/main.dart
@@ -34,5 +34,5 @@ void main() {
   // RU: Директор может знать больше одного рецепта строительства
   director.constructSportsCar(manualBuilder);
   final carManual = manualBuilder.getResult();
-  print("Car manual built:\n" + carManual.print());
+  print("Car manual built:\n${carManual.print()}");
 }
diff --git a/patterns/command/text_editor/main.dart b/patterns/command/text_editor/main.dart
index 5862594..2d1b217 100644
--- a/patterns/command/text_editor/main.dart
+++ b/patterns/command/text_editor/main.dart
@@ -32,5 +32,5 @@ void log({
 }) {
   final addOrUndo = isUndo ? 'Undo_' : '[➕] ';
   final description = '$addOrUndo$command';
-  print(description.padRight(72, '_') + '"$editorText"');
+  print('${description.padRight(72, '_')}"$editorText"');
 }
diff --git a/patterns/composite/products_and_boxes/products/box.dart b/patterns/composite/products_and_boxes/products/box.dart
index db2c88a..35e091b 100644
--- a/patterns/composite/products_and_boxes/products/box.dart
+++ b/patterns/composite/products_and_boxes/products/box.dart
@@ -9,8 +9,8 @@ class Box implements Product {
   @override
   String get content {
     final places = size > 1 ? "places: $size, " : "";
-    final _price = size > 1 ? "price: $price\$" : "$price\$";
-    return 'Box($places$_price)';
+    final localPrice = size > 1 ? "price: $price\$" : "$price\$";
+    return 'Box($places$localPrice)';
   }
 
   @override
diff --git a/patterns/state/manipulator_state/README.md b/patterns/state/manipulator_state/README.md
new file mode 100644
index 0000000..93d1e38
--- /dev/null
+++ b/patterns/state/manipulator_state/README.md
@@ -0,0 +1,76 @@
+# State Pattern
+State is a behavioral design pattern that lets an object alter its behavior when its internal state 
+changes. It appears as if the object changed its class.
+
+Tutorial: [here](https://refactoring.guru/design-patterns/state).
+
+### Online demo:
+Click on the picture to see the [demo](https://RefactoringGuru.github.io/design-patterns-dart/#/state/manipulator_state).
+
+[![image](https://user-images.githubusercontent.com/8049534/171070341-1decb58f-033b-4eb5-89d4-355aafa6b680.png)](https://refactoringguru.github.io/design-patterns-dart/#/state/manipulator_state)
+
+### Video
+https://user-images.githubusercontent.com/8049534/171499203-1400c3ae-d5cd-4e48-a0b6-0252f4345d19.mp4
+
+### Diagram:
+![image](https://user-images.githubusercontent.com/8049534/171740942-659d3ec9-8355-4078-a7d6-b4a338b41187.png)
+
+## Client code:
+### Change FreeState to MoveState:
+```dart
+class FreeState extends ManipulationState {
+  @override
+  void mouseDown(double x, double y) {
+    tryToSelectAndStartMovingShape(x, y);
+  }
+
+  bool tryToSelectAndStartMovingShape(double x, double y) {
+    final selectedShape = context.shapes.findShapeByCoordinates(x, y);
+
+    context.changeState(
+      MoveState(
+        startX: x,
+        startY: y,
+        selectedShape: selectedShape,
+      ),
+    );
+
+    return true;
+  }
+}
+```
+
+### Change MoveState to ResizableState:
+```dart
+class MoveState extends SelectionState {
+  @override
+  void mouseMove(double x, double y) {
+    selectedShape.move(x, y);
+    context.update();
+  }
+
+  @override
+  void mouseUp() {
+    context.changeState(
+      selectedShape.createSelectionState(),
+    );
+  }
+}
+```
+
+### Each shape has its own state manipulator:
+```dart
+class RectangleShape extends BaseShape {
+  @override
+  SelectionState createSelectionState() {
+    return ResizableState(selectedShape: this);
+  }
+}
+
+class CircleShape extends BaseShape {
+  @override
+  SelectionState createSelectionState() {
+    return InnerRadiusState(selectedShape: this);
+  }
+}
+```
diff --git a/patterns/state/manipulator_state/app/app.dart b/patterns/state/manipulator_state/app/app.dart
new file mode 100644
index 0000000..2e754d1
--- /dev/null
+++ b/patterns/state/manipulator_state/app/app.dart
@@ -0,0 +1,15 @@
+import '../pattern/manipulator.dart';
+import 'shapes.dart';
+import 'tool.dart';
+
+class App {
+  final Shapes shapes;
+  final Manipulator manipulator;
+  final List<Tool> tools;
+
+  App({
+    required this.shapes,
+    required this.manipulator,
+    required this.tools,
+  });
+}
diff --git a/patterns/state/manipulator_state/app/base_manipulation.dart b/patterns/state/manipulator_state/app/base_manipulation.dart
new file mode 100644
index 0000000..85db133
--- /dev/null
+++ b/patterns/state/manipulator_state/app/base_manipulation.dart
@@ -0,0 +1,87 @@
+part of manipulator;
+
+class BaseManipulator implements Manipulator {
+  BaseManipulator({
+    required this.shapes,
+    required ManipulationState initState,
+    required this.paintStyle,
+  }) : _state = initState {
+    _state._context = this;
+  }
+
+  @override
+  ManipulationState get state => _state;
+
+  @override
+  final Shapes shapes;
+
+  @override
+  final onStateChange = Event();
+
+  @override
+  final onUpdate = Event();
+
+  @override
+  var cursor = MouseCursor.defer;
+
+  @override
+  final PaintStyle paintStyle;
+
+  @override
+  void changeState(ManipulationState newState) {
+    if (_state == newState) {
+      return;
+    }
+
+    _state = newState;
+    _state._context = this;
+    _state.init();
+    onStateChange._emit();
+  }
+
+  @override
+  void update() {
+    onUpdate._emit();
+  }
+
+  @override
+  void mouseMove(double x, double y) {
+    _state.mouseMove(x, y);
+  }
+
+  @override
+  void mouseDown(double x, double y) {
+    _state.mouseDown(x, y);
+  }
+
+  @override
+  void mouseUp() {
+    _state.mouseUp();
+  }
+
+  @override
+  void mouseDoubleClick(double x, double y) {
+    _state.mouseDoubleClick(x, y);
+  }
+
+  @override
+  void keyDown(KeyEvent keyEvent) {
+    _state.keyDown(keyEvent);
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    _state.paint(canvas);
+  }
+
+  @override
+  String toString() {
+    return _state.toString();
+  }
+
+  ManipulationState _state;
+}
+
+class Event extends ChangeNotifier {
+  void _emit() => notifyListeners();
+}
diff --git a/patterns/state/manipulator_state/app/shapes.dart b/patterns/state/manipulator_state/app/shapes.dart
new file mode 100644
index 0000000..381b96c
--- /dev/null
+++ b/patterns/state/manipulator_state/app/shapes.dart
@@ -0,0 +1,36 @@
+import 'dart:collection';
+import 'dart:ui';
+
+import 'package:flutter/foundation.dart';
+
+import '../shapes/shape.dart';
+
+class Shapes with IterableMixin<Shape> {
+  final List<Shape> _shapes;
+
+  Shapes(List<Shape> shapes) : _shapes = shapes;
+
+  void add(Shape shape) {
+    _shapes.add(shape);
+    onChange._emit();
+  }
+
+  @override
+  Iterator<Shape> get iterator => _shapes.iterator;
+
+  final onChange = Event();
+
+  Shape? findShapeByCoordinates(x, y) {
+    for (final shape in _shapes.reversed) {
+      if (shape.rect.contains(Offset(x, y))) {
+        return shape;
+      }
+    }
+
+    return null;
+  }
+}
+
+class Event extends ChangeNotifier {
+  void _emit() => notifyListeners();
+}
diff --git a/patterns/state/manipulator_state/app/tool.dart b/patterns/state/manipulator_state/app/tool.dart
new file mode 100644
index 0000000..a3e7ca6
--- /dev/null
+++ b/patterns/state/manipulator_state/app/tool.dart
@@ -0,0 +1,13 @@
+import 'package:flutter/widgets.dart';
+
+import '../pattern/manipulator.dart';
+
+class Tool {
+  final Icon icon;
+  final ManipulationState state;
+
+  Tool({
+    required this.icon,
+    required this.state,
+  });
+}
diff --git a/patterns/state/manipulator_state/main.dart b/patterns/state/manipulator_state/main.dart
new file mode 100644
index 0000000..f235a2f
--- /dev/null
+++ b/patterns/state/manipulator_state/main.dart
@@ -0,0 +1,73 @@
+import 'package:flutter/material.dart';
+import 'package:material_design_icons_flutter/material_design_icons_flutter.dart';
+
+import 'app/app.dart';
+import 'app/shapes.dart';
+import 'app/tool.dart';
+import 'pattern/manipulator.dart';
+import 'states/creations/circle_creation_state.dart';
+import 'states/creations/rectangle_creation_state.dart';
+import 'states/creations/text_creation_state.dart';
+import 'states/free_sate.dart';
+import 'states/_/paint_style.dart';
+import 'widgets/current_state.dart';
+import 'widgets/drawing_board.dart';
+import 'widgets/tool_bar.dart';
+
+class ManipulatorStateApp extends StatefulWidget {
+  const ManipulatorStateApp({Key? key}) : super(key: key);
+
+  @override
+  State createState() => _ManipulatorStateAppState();
+}
+
+class _ManipulatorStateAppState extends State<ManipulatorStateApp> {
+  late final App app;
+
+  @override
+  void initState() {
+    final shapes = Shapes([]);
+    app = App(
+      shapes: shapes,
+      manipulator: BaseManipulator(
+        initState: FreeState(),
+        shapes: shapes,
+        paintStyle: PaintStyle(Colors.pink),
+      ),
+      tools: [
+        Tool(
+          icon: Icon(MdiIcons.cursorDefaultOutline),
+          state: FreeState(),
+        ),
+        Tool(
+          icon: Icon(MdiIcons.rectangleOutline),
+          state: RectangleCreationState(),
+        ),
+        Tool(
+          icon: Icon(MdiIcons.circleOutline),
+          state: CircleCreationState(),
+        ),
+        Tool(
+          icon: Icon(MdiIcons.formatTextVariant),
+          state: TextCreationState(),
+        ),
+      ],
+    );
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: SizedBox.expand(
+        child: Stack(
+          children: [
+            DrawingBoard(app: app),
+            ToolBar(app: app),
+            CurrentState(manipulator: app.manipulator),
+          ],
+        ),
+      ),
+    );
+  }
+}
diff --git a/patterns/state/manipulator_state/pattern/manipulation_state.dart b/patterns/state/manipulator_state/pattern/manipulation_state.dart
new file mode 100644
index 0000000..49221a2
--- /dev/null
+++ b/patterns/state/manipulator_state/pattern/manipulation_state.dart
@@ -0,0 +1,21 @@
+part of manipulator;
+
+class ManipulationState {
+  Manipulator get context => _context;
+
+  void init() {}
+
+  void mouseMove(double x, double y) {}
+
+  void mouseDown(double x, double y) {}
+
+  void mouseUp() {}
+
+  void mouseDoubleClick(double x, double y) {}
+
+  void keyDown(KeyEvent keyEvent) {}
+
+  void paint(Canvas canvas) {}
+
+  late Manipulator _context;
+}
diff --git a/patterns/state/manipulator_state/pattern/manipulator.dart b/patterns/state/manipulator_state/pattern/manipulator.dart
new file mode 100644
index 0000000..b7df969
--- /dev/null
+++ b/patterns/state/manipulator_state/pattern/manipulator.dart
@@ -0,0 +1,40 @@
+library manipulator;
+
+import 'package:flutter/material.dart';
+import '../states/_/paint_style.dart';
+import '../app/shapes.dart';
+
+part 'manipulation_state.dart';
+part '../app/base_manipulation.dart';
+
+abstract class Manipulator {
+  ManipulationState get state;
+
+  Shapes get shapes;
+
+  MouseCursor get cursor;
+
+  set cursor(MouseCursor cursor);
+
+  PaintStyle get paintStyle;
+
+  Event get onStateChange;
+
+  Event get onUpdate;
+
+  void changeState(ManipulationState newState);
+
+  void update();
+
+  void mouseMove(double x, double y);
+
+  void mouseDown(double x, double y);
+
+  void mouseUp();
+
+  void mouseDoubleClick(double x, double y);
+
+  void keyDown(KeyEvent keyEvent);
+
+  void paint(Canvas canvas);
+}
diff --git a/patterns/state/manipulator_state/shapes/base_shape.dart b/patterns/state/manipulator_state/shapes/base_shape.dart
new file mode 100644
index 0000000..c14eae8
--- /dev/null
+++ b/patterns/state/manipulator_state/shapes/base_shape.dart
@@ -0,0 +1,48 @@
+import 'package:flutter/material.dart';
+
+import 'shape.dart';
+
+abstract class BaseShape implements Shape {
+  BaseShape(double x, double y, double width, double height)
+      : _x = x,
+        _y = y,
+        _width = width,
+        _height = height;
+
+  @override
+  double get x => _x;
+
+  @override
+  double get y => _y;
+
+  @override
+  double get height => _height;
+
+  @override
+  double get width => _width;
+
+  @override
+  Rect get rect => Rect.fromLTWH(
+        _width < 0 ? x + _width : x,
+        _height < 0 ? y + _height : y,
+        _width.abs(),
+        _height.abs(),
+      );
+
+  @override
+  void move(double x, double y) {
+    _x = x;
+    _y = y;
+  }
+
+  @override
+  void resize(double width, double height) {
+    _width = width;
+    _height = height;
+  }
+
+  double _x;
+  double _y;
+  double _width;
+  double _height;
+}
diff --git a/patterns/state/manipulator_state/shapes/circle_shape.dart b/patterns/state/manipulator_state/shapes/circle_shape.dart
new file mode 100644
index 0000000..6efb1a5
--- /dev/null
+++ b/patterns/state/manipulator_state/shapes/circle_shape.dart
@@ -0,0 +1,86 @@
+import 'package:flutter/material.dart';
+
+import '../states/selections/inner_radius_state.dart';
+import '../states/selections/selection_state.dart';
+import 'base_shape.dart';
+
+class CircleShape extends BaseShape {
+  CircleShape(
+    super.x,
+    super.y,
+    super.width,
+    super.height,
+    double innerRadius,
+  ) {
+    this.innerRadius = innerRadius;
+  }
+
+  double get innerRadius =>
+      _turnOnInnerRadius && _drawInnerRadius ? _innerRadius : width / 2;
+
+  set innerRadius(double newValue) {
+    if (newValue > width / 2) {
+      _turnOnInnerRadius = false;
+      _innerRadius = newValue;
+      _buildPath();
+      return;
+    } else if (newValue < 1) {
+      newValue = 1;
+    }
+
+    _drawInnerRadius = true;
+    _turnOnInnerRadius = _drawInnerRadius;
+    _innerRadius = newValue;
+    _buildPath();
+  }
+
+  @override
+  void resize(double width, double height) {
+    super.resize(width, height);
+    _drawInnerRadius = width > _innerRadius * 2;
+    _buildPath();
+  }
+
+  @override
+  void move(double x, double y) {
+    super.move(x, y);
+    _buildPath();
+  }
+
+  @override
+  SelectionState createSelectionState() {
+    return InnerRadiusState(selectedShape: this);
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    canvas.drawPath(
+      _path,
+      Paint()..color = Colors.white,
+    );
+  }
+
+  void _buildPath() {
+    _path = Path()
+      ..fillType = PathFillType.evenOdd
+      ..addOval(rect);
+
+    if (_drawInnerRadius) {
+      final fixHeight = height / width;
+      final doubleRadius = innerRadius * 2;
+      _path.addOval(
+        Rect.fromLTWH(
+          x + innerRadius,
+          y + innerRadius * fixHeight,
+          width - doubleRadius,
+          height - doubleRadius * fixHeight,
+        ),
+      );
+    }
+  }
+
+  late double _innerRadius;
+  late Path _path;
+  bool _drawInnerRadius = true;
+  bool _turnOnInnerRadius = true;
+}
diff --git a/patterns/state/manipulator_state/shapes/marker_shape.dart b/patterns/state/manipulator_state/shapes/marker_shape.dart
new file mode 100644
index 0000000..aef7acf
--- /dev/null
+++ b/patterns/state/manipulator_state/shapes/marker_shape.dart
@@ -0,0 +1,18 @@
+import 'package:flutter/material.dart';
+
+import '../states/selections/selection_state.dart';
+import 'base_shape.dart';
+import 'shape.dart';
+
+class MarkerShape extends BaseShape {
+  MarkerShape(double size) : super(0, 0, size, -1);
+
+  @override
+  Rect get rect => Rect.fromLTWH(x - width, y - width, width * 2, width * 2);
+
+  @override
+  void paint(Canvas canvas) => throw UnimplementedError();
+
+  @override
+  SelectionState<Shape> createSelectionState() => throw UnimplementedError();
+}
diff --git a/patterns/state/manipulator_state/shapes/rectangle_shape.dart b/patterns/state/manipulator_state/shapes/rectangle_shape.dart
new file mode 100644
index 0000000..c6eeedd
--- /dev/null
+++ b/patterns/state/manipulator_state/shapes/rectangle_shape.dart
@@ -0,0 +1,22 @@
+import 'package:flutter/material.dart';
+
+import '../states/selections/resizable_state.dart';
+import '../states/selections/selection_state.dart';
+import 'base_shape.dart';
+
+class RectangleShape extends BaseShape {
+  RectangleShape(super.x, super.y, super.width, super.height);
+
+  @override
+  SelectionState createSelectionState() {
+    return ResizableState(selectedShape: this);
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    canvas.drawRect(
+      rect,
+      Paint()..color = Colors.white,
+    );
+  }
+}
diff --git a/patterns/state/manipulator_state/shapes/shape.dart b/patterns/state/manipulator_state/shapes/shape.dart
new file mode 100644
index 0000000..4484439
--- /dev/null
+++ b/patterns/state/manipulator_state/shapes/shape.dart
@@ -0,0 +1,23 @@
+import 'dart:ui';
+
+import '../states/selections/selection_state.dart';
+
+abstract class Shape {
+  double get x;
+
+  double get y;
+
+  double get width;
+
+  double get height;
+
+  Rect get rect;
+
+  void move(double x, double y);
+
+  void resize(double width, double height);
+
+  void paint(Canvas canvas);
+
+  SelectionState createSelectionState();
+}
diff --git a/patterns/state/manipulator_state/shapes/text_shape.dart b/patterns/state/manipulator_state/shapes/text_shape.dart
new file mode 100644
index 0000000..9c8d51f
--- /dev/null
+++ b/patterns/state/manipulator_state/shapes/text_shape.dart
@@ -0,0 +1,74 @@
+import 'dart:ui';
+
+import '../states/selections/selection_state.dart';
+import '../states/selections/text_resize_state.dart';
+import 'base_shape.dart';
+
+class TextShape extends BaseShape {
+  TextShape(double x, double y, double height) : super(x, y, 0, height) {
+    _buildParagraph(height);
+  }
+
+  String get text => _text;
+
+  set text(String newText) {
+    _text = newText;
+    _buildParagraph(_textHeight);
+  }
+
+  double get userHeight => _textHeight;
+
+  Paragraph get paragraph => _paragraph;
+
+  @override
+  Rect get rect {
+    final fixY = height - _textHeight;
+    return Rect.fromLTWH(x, y + fixY, width, height - fixY);
+  }
+
+  @override
+  void paint(Canvas can) {
+    can.drawParagraph(_paragraph, Offset(x, y));
+  }
+
+  @override
+  SelectionState createSelectionState() {
+    return TextResizeState(selectedShape: this);
+  }
+
+  @override
+  void resize(double _, double newHeight) {
+    if (newHeight < 2) {
+      newHeight = 2;
+    }
+
+    final oldWidth = width;
+    _buildParagraph(newHeight);
+    final centerX = x - (width - oldWidth) / 2;
+    move(centerX, y);
+  }
+
+  void _buildParagraph(double newHeight) {
+    _textHeight = newHeight;
+
+    final style = ParagraphStyle(
+      textDirection: TextDirection.ltr,
+    );
+    final tStyle = TextStyle(
+      fontFamily: 'Arial',
+      color: Color(0xffffffff),
+      fontSize: newHeight,
+    );
+    _paragraph = (ParagraphBuilder(style)
+          ..pushStyle(tStyle)
+          ..addText(_text))
+        .build();
+    _paragraph.layout(ParagraphConstraints(width: double.infinity));
+
+    super.resize(_paragraph.maxIntrinsicWidth, _paragraph.height);
+  }
+
+  late Paragraph _paragraph;
+  String _text = 'Text';
+  late double _textHeight;
+}
diff --git a/patterns/state/manipulator_state/states/_/creation_state.dart b/patterns/state/manipulator_state/states/_/creation_state.dart
new file mode 100644
index 0000000..3485c86
--- /dev/null
+++ b/patterns/state/manipulator_state/states/_/creation_state.dart
@@ -0,0 +1,75 @@
+import 'dart:ui';
+
+import '../../pattern/manipulator.dart';
+import '../../shapes/shape.dart';
+
+abstract class CreationState extends ManipulationState {
+  Shape createShape(double x, double y);
+
+  @override
+  void mouseDown(double x, double y) {
+    _startCreatingShape(x, y);
+  }
+
+  @override
+  void mouseMove(double x, double y) {
+    if (_isCreatingNotStart) {
+      return;
+    }
+
+    _resizeNewShape(x, y);
+  }
+
+  @override
+  void mouseUp() {
+    if (_isCreatingNotStart) {
+      return;
+    }
+
+    _repositionNewShape();
+    context.shapes.add(_newShape!);
+    _finishCreatingShape();
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    _newShape?.paint(canvas);
+  }
+
+  bool get _isCreatingNotStart => _newShape == null;
+
+  void _startCreatingShape(double x, double y) {
+    _startX = x;
+    _startY = y;
+    _newShape = createShape(x, y);
+  }
+
+  void _resizeNewShape(double x, double y) {
+    _isDragged = true;
+    _newShape!.resize(x - _startX, y - _startY);
+    context.update();
+  }
+
+  void _repositionNewShape() {
+    if (!_isDragged) {
+      _newShape!.resize(100, 100);
+      final rect = _newShape!.rect;
+      _newShape!.move(
+        _startX - rect.width / 2,
+        _startY - rect.height / 2,
+      );
+    }
+  }
+
+  void _finishCreatingShape() {
+    final selectedShapeState = _newShape!.createSelectionState();
+    context.changeState(selectedShapeState);
+    _isDragged = false;
+    _newShape = null;
+  }
+
+  var _startX = 0.0;
+  var _startY = 0.0;
+  Shape? _newShape;
+  var _isDragged = false;
+}
diff --git a/patterns/state/manipulator_state/states/_/marker.dart b/patterns/state/manipulator_state/states/_/marker.dart
new file mode 100644
index 0000000..ea9a188
--- /dev/null
+++ b/patterns/state/manipulator_state/states/_/marker.dart
@@ -0,0 +1,35 @@
+import 'package:flutter/rendering.dart';
+
+import '../../shapes/marker_shape.dart';
+import '../../shapes/shape.dart';
+import 'sub_states/child_state.dart';
+import 'sub_states/parent_state.dart';
+
+abstract class Marker<T extends Shape> extends ChildState<T> {
+  Marker({
+    required ParentState<T> parentState,
+  }) : super(
+          parentState: parentState,
+          markerShape: MarkerShape(5),
+        );
+
+  @override
+  MouseCursor get hoverCursor {
+    final rect = parentState.selectedShape.rect;
+    final corner = Offset(markerShape.x, markerShape.y);
+
+    if (corner == rect.topLeft) {
+      return SystemMouseCursors.resizeUpLeft;
+    } else if (corner == rect.topRight) {
+      return SystemMouseCursors.resizeUpRight;
+    } else if (corner == rect.bottomLeft) {
+      return SystemMouseCursors.resizeDownLeft;
+    } else if (corner == rect.bottomRight) {
+      return SystemMouseCursors.resizeDownRight;
+    }
+
+    return SystemMouseCursors.move;
+  }
+
+  T get selectedShape => parentState.selectedShape;
+}
diff --git a/patterns/state/manipulator_state/states/_/mixins/hover_shape_mixin.dart b/patterns/state/manipulator_state/states/_/mixins/hover_shape_mixin.dart
new file mode 100644
index 0000000..6e5679f
--- /dev/null
+++ b/patterns/state/manipulator_state/states/_/mixins/hover_shape_mixin.dart
@@ -0,0 +1,48 @@
+import 'package:flutter/material.dart';
+
+import '../../../pattern/manipulator.dart';
+import '../../../shapes/shape.dart';
+
+mixin HoverShapeMixin implements ManipulationState {
+  Shape? findShapeByCoordinates(double x, double y) {
+    return context.shapes.findShapeByCoordinates(x, y);
+  }
+
+  Shape? get hoverShape => _hoverShape;
+
+  bool get isHover => _hoverShape != null;
+
+  @override
+  void mouseMove(double x, double y) {
+    final newHover = findShapeByCoordinates(x, y);
+
+    if (newHover == _hoverShape) {
+      return;
+    }
+
+    _hoverShape = newHover;
+
+    if (newHover == null) {
+      onMouseLeave();
+    } else {
+      onHover();
+    }
+
+    context.update();
+  }
+
+  void onHover() {}
+
+  void onMouseLeave() {}
+
+  @override
+  void paint(Canvas canvas) {
+    if (_hoverShape == null) {
+      return;
+    }
+
+    context.paintStyle.paintHover(canvas, _hoverShape!);
+  }
+
+  Shape? _hoverShape;
+}
diff --git a/patterns/state/manipulator_state/states/_/paint_style.dart b/patterns/state/manipulator_state/states/_/paint_style.dart
new file mode 100644
index 0000000..a26d70e
--- /dev/null
+++ b/patterns/state/manipulator_state/states/_/paint_style.dart
@@ -0,0 +1,95 @@
+import 'package:flutter/material.dart';
+
+import '../../shapes/circle_shape.dart';
+import '../../shapes/shape.dart';
+import '../../shapes/text_shape.dart';
+import '../selections/text/text_cursor.dart';
+
+class PaintStyle {
+  PaintStyle(this.color)
+      : _selectStroke = Paint()
+          ..color = color
+          ..style = PaintingStyle.stroke
+          ..strokeWidth = 2.0,
+        _markerStroke = Paint()
+          ..color = color
+          ..style = PaintingStyle.stroke
+          ..strokeWidth = 1.5,
+        _markerFill = Paint()
+          ..style = PaintingStyle.fill
+          ..color = Colors.black;
+
+  final Color color;
+
+  void paintHover(Canvas canvas, Shape shape) {
+    canvas.drawRect(
+      shape.rect.deflate(1),
+      _selectStroke,
+    );
+  }
+
+  void paintSelection(Canvas canvas, Shape shape) {
+    paintHover(canvas, shape);
+  }
+
+  void paintMarker(Canvas canvas, Shape markerShape) {
+    final point = Offset(markerShape.x, markerShape.y);
+    canvas.drawCircle(
+      point,
+      markerShape.width,
+      _markerFill,
+    );
+    canvas.drawCircle(
+      point,
+      markerShape.width,
+      _markerStroke,
+    );
+  }
+
+  void paintRadiusLine(CircleShape selectedShape, Canvas canvas) {
+    canvas.save();
+    canvas.translate(selectedShape.x, selectedShape.y);
+    final x = selectedShape.width - selectedShape.innerRadius;
+    final y = selectedShape.height / 2;
+    canvas.drawLine(
+      Offset(x, y),
+      Offset(selectedShape.width, y),
+      Paint()
+        ..color = color
+        ..strokeWidth = 1.5,
+    );
+
+    canvas.restore();
+  }
+
+  void paintSelectedText(TextShape selectedShape, Canvas canvas) {
+    canvas.drawRect(
+      selectedShape.rect,
+      Paint()..color = color.withOpacity(0.3),
+    );
+  }
+
+  void paintTextCursor(
+    TextCursor cursor,
+    TextShape selectedShape,
+    Canvas canvas,
+  ) {
+    canvas.drawLine(
+      Offset(
+        cursor.xCoordinate,
+        selectedShape.y + (selectedShape.height - selectedShape.userHeight) + 2,
+      ),
+      Offset(
+        cursor.xCoordinate,
+        selectedShape.y + (selectedShape.height) - 2,
+      ),
+      Paint()
+        ..strokeWidth = 2.2
+        ..color = Colors.white,
+    );
+  }
+
+  final Paint _selectStroke;
+  final Paint _markerStroke;
+  final Paint _markerFill;
+}
diff --git a/patterns/state/manipulator_state/states/_/sub_states/child_state.dart b/patterns/state/manipulator_state/states/_/sub_states/child_state.dart
new file mode 100644
index 0000000..b1a1747
--- /dev/null
+++ b/patterns/state/manipulator_state/states/_/sub_states/child_state.dart
@@ -0,0 +1,88 @@
+import 'dart:ui';
+
+import 'package:flutter/services.dart';
+
+import '../../../shapes/shape.dart';
+import '../../../pattern/manipulator.dart';
+import '../../_/mixins/hover_shape_mixin.dart';
+import 'parent_state.dart';
+
+abstract class ChildState<T extends Shape> extends ManipulationState
+    with HoverShapeMixin {
+  final ParentState<T> parentState;
+  final Shape markerShape;
+
+  ChildState({
+    required this.parentState,
+    required this.markerShape,
+  }) {
+    updatePosition();
+  }
+
+  void updatePosition();
+
+  void mouseDragAction(double x, double y);
+
+  MouseCursor get hoverCursor;
+
+  @override
+  void onHover() {
+    context.cursor = hoverCursor;
+  }
+
+  @override
+  void onMouseLeave() {
+    context.cursor = SystemMouseCursors.basic;
+  }
+
+  @override
+  void mouseDown(double x, double y) {
+    if (isHover) {
+      _isDown = true;
+      context.changeState(this);
+    }
+  }
+
+  @override
+  void mouseMove(double x, double y) {
+    super.mouseMove(x, y);
+    if (_isDown) {
+      mouseDragAction(x, y);
+      parentState.updateKids();
+      context.cursor = hoverCursor;
+      context.update();
+    }
+  }
+
+  @override
+  void mouseUp() {
+    if (!_isDown) {
+      return;
+    }
+
+    context.changeState(parentState);
+    _isDown = false;
+
+    if (!isHover) {
+      context.cursor = SystemMouseCursors.basic;
+      context.update();
+    }
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    parentState.paint(canvas);
+  }
+
+  @override
+  Manipulator get context => parentState.context;
+
+  @override
+  Shape? findShapeByCoordinates(double x, double y) {
+    return markerShape.rect.contains(Offset(x, y)) ? markerShape : null;
+  }
+
+  bool get isDown => _isDown;
+
+  bool _isDown = false;
+}
diff --git a/patterns/state/manipulator_state/states/_/sub_states/parent_state.dart b/patterns/state/manipulator_state/states/_/sub_states/parent_state.dart
new file mode 100644
index 0000000..ba0638f
--- /dev/null
+++ b/patterns/state/manipulator_state/states/_/sub_states/parent_state.dart
@@ -0,0 +1,56 @@
+import 'dart:ui';
+
+import '../../selections/selection_state.dart';
+import 'child_state.dart';
+import '../../../shapes/shape.dart';
+
+abstract class ParentState<T extends Shape> extends SelectionState<T> {
+  ParentState({
+    required super.selectedShape,
+  });
+
+  void addChildren(List<ChildState> markers) {
+    _children.addAll(markers);
+  }
+
+  void updateKids() {
+    for (final child in _children) {
+      child.updatePosition();
+    }
+  }
+
+  @override
+  void mouseDown(double x, double y) {
+    for (final child in _children) {
+      child.mouseDown(x, y);
+      if (context.state == child) {
+        return;
+      }
+    }
+
+    super.mouseDown(x, y);
+  }
+
+  @override
+  void mouseMove(double x, double y) {
+    super.mouseMove(x, y);
+
+    for (final child in _children) {
+      child.mouseMove(x, y);
+      if (child.isHover) {
+        return;
+      }
+    }
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    super.paint(canvas);
+
+    for (final child in _children) {
+      context.paintStyle.paintMarker(canvas, child.markerShape);
+    }
+  }
+
+  final _children = <ChildState>[];
+}
diff --git a/patterns/state/manipulator_state/states/creations/circle_creation_state.dart b/patterns/state/manipulator_state/states/creations/circle_creation_state.dart
new file mode 100644
index 0000000..dabf811
--- /dev/null
+++ b/patterns/state/manipulator_state/states/creations/circle_creation_state.dart
@@ -0,0 +1,15 @@
+import '../../shapes/circle_shape.dart';
+import '../../shapes/shape.dart';
+import '../_/creation_state.dart';
+
+class CircleCreationState extends CreationState {
+  @override
+  Shape createShape(double x, double y) {
+    return CircleShape(x, y, 100, 100, 25);
+  }
+
+  @override
+  String toString() {
+    return 'Circle Creation State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/creations/rectangle_creation_state.dart b/patterns/state/manipulator_state/states/creations/rectangle_creation_state.dart
new file mode 100644
index 0000000..4a61891
--- /dev/null
+++ b/patterns/state/manipulator_state/states/creations/rectangle_creation_state.dart
@@ -0,0 +1,15 @@
+import '../../shapes/rectangle_shape.dart';
+import '../../shapes/shape.dart';
+import '../_/creation_state.dart';
+
+class RectangleCreationState extends CreationState {
+  @override
+  Shape createShape(double x, double y) {
+    return RectangleShape(x, y, 0, 0);
+  }
+
+  @override
+  String toString() {
+    return 'Rectangle Creation State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/creations/text_creation_state.dart b/patterns/state/manipulator_state/states/creations/text_creation_state.dart
new file mode 100644
index 0000000..4425a84
--- /dev/null
+++ b/patterns/state/manipulator_state/states/creations/text_creation_state.dart
@@ -0,0 +1,15 @@
+import '../../shapes/shape.dart';
+import '../../shapes/text_shape.dart';
+import '../_/creation_state.dart';
+
+class TextCreationState extends CreationState {
+  @override
+  Shape createShape(double x, double y) {
+    return TextShape(x, y, 2);
+  }
+
+  @override
+  String toString() {
+    return 'Text Creation State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/free_sate.dart b/patterns/state/manipulator_state/states/free_sate.dart
new file mode 100644
index 0000000..e001070
--- /dev/null
+++ b/patterns/state/manipulator_state/states/free_sate.dart
@@ -0,0 +1,33 @@
+import '../pattern/manipulator.dart';
+import '_/mixins/hover_shape_mixin.dart';
+import 'selections/move_state.dart';
+
+class FreeState extends ManipulationState with HoverShapeMixin {
+  @override
+  void mouseDown(double x, double y) {
+    tryToSelectAndStartMovingShape(x, y);
+  }
+
+  bool tryToSelectAndStartMovingShape(double x, double y) {
+    final selectedShape = context.shapes.findShapeByCoordinates(x, y);
+
+    if (selectedShape == null) {
+      return false;
+    }
+
+    context.changeState(
+      MoveState(
+        startX: x,
+        startY: y,
+        selectedShape: selectedShape,
+      ),
+    );
+
+    return true;
+  }
+
+  @override
+  String toString() {
+    return 'Free State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/inner_radius_markers/inner_radius_marker_state.dart b/patterns/state/manipulator_state/states/selections/inner_radius_markers/inner_radius_marker_state.dart
new file mode 100644
index 0000000..ae60e1b
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/inner_radius_markers/inner_radius_marker_state.dart
@@ -0,0 +1,32 @@
+import 'package:flutter/src/services/mouse_cursor.dart';
+
+import '../../../shapes/circle_shape.dart';
+import '../../_/marker.dart';
+
+class InnerRadiusMarkerState extends Marker<CircleShape> {
+  InnerRadiusMarkerState({required super.parentState});
+
+  @override
+  void mouseDragAction(double x, double y) {
+    selectedShape.innerRadius = selectedShape.rect.right - x;
+  }
+
+  @override
+  void updatePosition() {
+    final y = selectedShape.y + selectedShape.height / 2;
+    final x = selectedShape.x + selectedShape.width;
+
+    markerShape.move(
+      x - selectedShape.innerRadius,
+      y,
+    );
+  }
+
+  @override
+  MouseCursor get hoverCursor => SystemMouseCursors.resizeLeftRight;
+
+  @override
+  String toString() {
+    return '${parentState.toString()} + Inner Radius Marker State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/inner_radius_state.dart b/patterns/state/manipulator_state/states/selections/inner_radius_state.dart
new file mode 100644
index 0000000..898b5b5
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/inner_radius_state.dart
@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+
+import '../../shapes/circle_shape.dart';
+import 'inner_radius_markers/inner_radius_marker_state.dart';
+import 'resizable_state.dart';
+
+class InnerRadiusState extends ResizableState<CircleShape> {
+  InnerRadiusState({required super.selectedShape}) {
+    addChildren([
+      InnerRadiusMarkerState(parentState: this),
+    ]);
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    context.paintStyle.paintRadiusLine(selectedShape, canvas);
+    super.paint(canvas);
+  }
+
+  @override
+  String toString() {
+    return '${super.toString()} + Inner Radius State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/move_state.dart b/patterns/state/manipulator_state/states/selections/move_state.dart
new file mode 100644
index 0000000..8f0773c
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/move_state.dart
@@ -0,0 +1,31 @@
+import 'selection_state.dart';
+
+class MoveState extends SelectionState {
+  final double startX;
+  final double startY;
+
+  MoveState({
+    required double startX,
+    required double startY,
+    required super.selectedShape,
+  })  : startX = startX - selectedShape.x,
+        startY = startY - selectedShape.y;
+
+  @override
+  void mouseMove(double x, double y) {
+    selectedShape.move(x - startX, y - startY);
+    context.update();
+  }
+
+  @override
+  void mouseUp() {
+    context.changeState(
+      selectedShape.createSelectionState(),
+    );
+  }
+
+  @override
+  String toString() {
+    return '${super.toString()} + Moving State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/resizable_markers/bottom_left_marker_state.dart b/patterns/state/manipulator_state/states/selections/resizable_markers/bottom_left_marker_state.dart
new file mode 100644
index 0000000..9d2a1f8
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/resizable_markers/bottom_left_marker_state.dart
@@ -0,0 +1,30 @@
+import '../../_/marker.dart';
+
+class BottomLeftMarkerState extends Marker {
+  BottomLeftMarkerState({
+    required super.parentState,
+  });
+
+  @override
+  void mouseDragAction(double x, double y) {
+    final newX = selectedShape.width + selectedShape.x - x;
+    final newY = y - selectedShape.y;
+
+    selectedShape
+      ..resize(newX, newY)
+      ..move(x, selectedShape.y);
+  }
+
+  @override
+  void updatePosition() {
+    markerShape.move(
+      selectedShape.x,
+      selectedShape.y + selectedShape.height,
+    );
+  }
+
+  @override
+  String toString() {
+    return '${parentState.toString()} + Bottom Left Marker State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/resizable_markers/bottom_right_marker_state.dart b/patterns/state/manipulator_state/states/selections/resizable_markers/bottom_right_marker_state.dart
new file mode 100644
index 0000000..5db6e10
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/resizable_markers/bottom_right_marker_state.dart
@@ -0,0 +1,27 @@
+import '../../_/marker.dart';
+
+class BottomRightMarkerState extends Marker {
+  BottomRightMarkerState({
+    required super.parentState,
+  });
+
+  @override
+  void mouseDragAction(double x, double y) {
+    selectedShape.resize(
+      x - selectedShape.x,
+      y - selectedShape.y,
+    );
+  }
+
+  @override
+  void updatePosition() {
+    final width = selectedShape.x + selectedShape.width;
+    final height = selectedShape.y + selectedShape.height;
+    markerShape.move(width, height);
+  }
+
+  @override
+  String toString() {
+    return '${parentState.toString()} + Bottom Right Marker State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/resizable_markers/top_left_marker_state.dart b/patterns/state/manipulator_state/states/selections/resizable_markers/top_left_marker_state.dart
new file mode 100644
index 0000000..74bd92d
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/resizable_markers/top_left_marker_state.dart
@@ -0,0 +1,30 @@
+import '../../_/marker.dart';
+
+class TopLeftMarkerState extends Marker {
+  TopLeftMarkerState({
+    required super.parentState,
+  });
+
+  @override
+  void mouseDragAction(double x, double y) {
+    final newWidth = selectedShape.width + selectedShape.x - x;
+    final newHeight = selectedShape.height + selectedShape.y - y;
+
+    selectedShape
+      ..resize(newWidth, newHeight)
+      ..move(x, y);
+  }
+
+  @override
+  void updatePosition() {
+    markerShape.move(
+      selectedShape.x,
+      selectedShape.y,
+    );
+  }
+
+  @override
+  String toString() {
+    return '${parentState.toString()} + Top Left Marker State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/resizable_markers/top_right_marker_state.dart b/patterns/state/manipulator_state/states/selections/resizable_markers/top_right_marker_state.dart
new file mode 100644
index 0000000..f03f484
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/resizable_markers/top_right_marker_state.dart
@@ -0,0 +1,30 @@
+import '../../_/marker.dart';
+
+class TopRightMarkerState extends Marker {
+  TopRightMarkerState({
+    required super.parentState,
+  });
+
+  @override
+  void mouseDragAction(double x, double y) {
+    final width = x - selectedShape.x;
+    final height = selectedShape.height + selectedShape.y - y;
+
+    selectedShape
+      ..resize(width, height)
+      ..move(selectedShape.x, y);
+  }
+
+  @override
+  void updatePosition() {
+    markerShape.move(
+      selectedShape.x + selectedShape.width,
+      selectedShape.y,
+    );
+  }
+
+  @override
+  String toString() {
+    return '${parentState.toString()} + Top Right Marker State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/resizable_state.dart b/patterns/state/manipulator_state/states/selections/resizable_state.dart
new file mode 100644
index 0000000..92236b0
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/resizable_state.dart
@@ -0,0 +1,22 @@
+import 'resizable_markers/bottom_left_marker_state.dart';
+import 'resizable_markers/bottom_right_marker_state.dart';
+import 'resizable_markers/top_left_marker_state.dart';
+import 'resizable_markers/top_right_marker_state.dart';
+import '../_/sub_states/parent_state.dart';
+import '../../shapes/shape.dart';
+
+class ResizableState<T extends Shape> extends ParentState<T> {
+  ResizableState({required super.selectedShape}) {
+    addChildren([
+      TopLeftMarkerState(parentState: this),
+      TopRightMarkerState(parentState: this),
+      BottomRightMarkerState(parentState: this),
+      BottomLeftMarkerState(parentState: this),
+    ]);
+  }
+
+  @override
+  String toString() {
+    return '${super.toString()} + Resizable State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/selection_state.dart b/patterns/state/manipulator_state/states/selections/selection_state.dart
new file mode 100644
index 0000000..26fb82d
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/selection_state.dart
@@ -0,0 +1,30 @@
+import 'package:flutter/material.dart';
+
+import '../../shapes/shape.dart';
+import '../free_sate.dart';
+
+class SelectionState<TShape extends Shape> extends FreeState {
+  final TShape selectedShape;
+
+  SelectionState({required this.selectedShape});
+
+  @override
+  void mouseDown(double x, double y) {
+    final isShapeNotSelected = !tryToSelectAndStartMovingShape(x, y);
+
+    if (isShapeNotSelected) {
+      context.changeState(FreeState());
+    }
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    super.paint(canvas);
+    context.paintStyle.paintSelection(canvas, selectedShape);
+  }
+
+  @override
+  String toString() {
+    return '${super.toString()} + Selection State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/text/keyboard_actions.dart b/patterns/state/manipulator_state/states/selections/text/keyboard_actions.dart
new file mode 100644
index 0000000..ed0f11b
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/text/keyboard_actions.dart
@@ -0,0 +1,31 @@
+import 'package:flutter/services.dart';
+
+class KeyboardActions {
+  final Map<PhysicalKeyboardKey, void Function()> actions;
+  final void Function(String) inputCharAction;
+
+  KeyboardActions({
+    required this.actions,
+    required this.inputCharAction,
+  });
+
+  void keyDown(KeyEvent keyEvent) {
+    final isNotKeyDown =
+        !(keyEvent is KeyDownEvent || keyEvent is KeyRepeatEvent);
+
+    if (isNotKeyDown) {
+      return;
+    }
+
+    final foundEvent = actions[keyEvent.physicalKey];
+
+    if (foundEvent != null) {
+      foundEvent.call();
+      return;
+    }
+
+    if (keyEvent.character != null) {
+      inputCharAction.call(keyEvent.character!);
+    }
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/text/text_cursor.dart b/patterns/state/manipulator_state/states/selections/text/text_cursor.dart
new file mode 100644
index 0000000..b09f9b8
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/text/text_cursor.dart
@@ -0,0 +1,89 @@
+import 'dart:ui';
+
+import '../../../shapes/text_shape.dart';
+
+class TextCursor {
+  TextCursor(this._textShape) : _xPosition = _textShape.x;
+
+  double get xCoordinate => _xPosition;
+
+  void changePosition(double x) {
+    x = x - _textShape.x;
+
+    final pos =
+        _textShape.paragraph.getPositionForOffset(Offset(x, _textShape.y));
+
+    _charIndex = pos.offset;
+    _xPosition = _textShape.x;
+
+    final range = _textShape.paragraph.getBoxesForRange(
+      pos.offset - 1,
+      pos.offset,
+    );
+
+    if (range.isNotEmpty) {
+      _xPosition += range.first.right;
+    }
+  }
+
+  void inputText(String char) {
+    _changeText(char: char);
+    moveRight();
+  }
+
+  void backspace() {
+    if (_charIndex <= 0) {
+      return;
+    }
+
+    _changeText(removeChars: -1);
+    moveLeft();
+  }
+
+  void moveLeft() {
+    _charIndex--;
+    _xPosition = _textShape.x;
+
+    if (_charIndex <= 0) {
+      _charIndex = 0;
+      return;
+    }
+
+    final range =
+        _textShape.paragraph.getBoxesForRange(_charIndex - 1, _charIndex);
+
+    if (range.isNotEmpty) {
+      _xPosition += range.first.right;
+    }
+  }
+
+  void moveRight() {
+    _charIndex++;
+    _xPosition = _textShape.x;
+
+    if (_charIndex >= _textShape.text.length) {
+      _charIndex = _textShape.text.length;
+      _xPosition += _textShape.width;
+      return;
+    }
+
+    final range =
+        _textShape.paragraph.getBoxesForRange(_charIndex - 1, _charIndex);
+
+    if (range.isNotEmpty) {
+      _xPosition += range.first.right;
+    }
+  }
+
+  void _changeText({String char = '', int removeChars = 0}) {
+    final start = _textShape.text.substring(0, _charIndex + removeChars);
+    final end = _textShape.text.length > start.length
+        ? _textShape.text.substring(_charIndex)
+        : '';
+    _textShape.text = '$start$char$end';
+  }
+
+  final TextShape _textShape;
+  int _charIndex = 0;
+  late double _xPosition = 0;
+}
diff --git a/patterns/state/manipulator_state/states/selections/text/text_cursor_animation.dart b/patterns/state/manipulator_state/states/selections/text/text_cursor_animation.dart
new file mode 100644
index 0000000..22b6bee
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/text/text_cursor_animation.dart
@@ -0,0 +1,30 @@
+import 'dart:async';
+
+class TextCursorAnimation {
+  final Duration speed;
+  final void Function() onBlink;
+
+  TextCursorAnimation({
+    required this.speed,
+    required this.onBlink,
+  }) {
+    _timer = Timer.periodic(speed, (_) {
+      _isShowCursor = !_isShowCursor;
+      onBlink.call();
+    });
+  }
+
+  bool get isVisible => _isShowCursor;
+
+  void touch() {
+    _isShowCursor = true;
+    onBlink.call();
+  }
+
+  void dispose() {
+    _timer.cancel();
+  }
+
+  bool _isShowCursor = true;
+  late Timer _timer;
+}
diff --git a/patterns/state/manipulator_state/states/selections/text/text_size_marker_state.dart b/patterns/state/manipulator_state/states/selections/text/text_size_marker_state.dart
new file mode 100644
index 0000000..05c250f
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/text/text_size_marker_state.dart
@@ -0,0 +1,30 @@
+import 'package:flutter/services.dart';
+
+import '../../../shapes/text_shape.dart';
+import '../../_/marker.dart';
+
+class TextSizeMarkerState extends Marker<TextShape> {
+  TextSizeMarkerState({required super.parentState});
+
+  @override
+  void mouseDragAction(double x, double y) {
+    final newHeight =
+        y - selectedShape.y - (selectedShape.height - selectedShape.userHeight);
+
+    selectedShape.resize(0, newHeight);
+  }
+
+  @override
+  void updatePosition() {
+    final bottomCenter = selectedShape.rect.bottomCenter;
+    markerShape.move(bottomCenter.dx, bottomCenter.dy);
+  }
+
+  @override
+  MouseCursor get hoverCursor => SystemMouseCursors.resizeUpDown;
+
+  @override
+  String toString() {
+    return '${parentState.toString()} + Text Size Marker State';
+  }
+}
diff --git a/patterns/state/manipulator_state/states/selections/text_edit_state.dart b/patterns/state/manipulator_state/states/selections/text_edit_state.dart
new file mode 100644
index 0000000..c11b288
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/text_edit_state.dart
@@ -0,0 +1,87 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+import '../../shapes/text_shape.dart';
+import 'selection_state.dart';
+import 'text/keyboard_actions.dart';
+import 'text/text_cursor.dart';
+import 'text/text_cursor_animation.dart';
+
+class TextEditState extends SelectionState<TextShape> {
+  TextEditState({
+    required Offset startPointer,
+    required super.selectedShape,
+  }) : _startPointer = startPointer;
+
+  @override
+  void init() {
+    _textCursor = TextCursor(selectedShape)..changePosition(_startPointer.dx);
+
+    _keyboardActions = KeyboardActions(
+      actions: {
+        PhysicalKeyboardKey.backspace: _textCursor.backspace,
+        PhysicalKeyboardKey.arrowLeft: _textCursor.moveLeft,
+        PhysicalKeyboardKey.arrowRight: _textCursor.moveRight,
+      },
+      inputCharAction: _textCursor.inputText,
+    );
+
+    _animationCursor = TextCursorAnimation(
+      speed: Duration(milliseconds: 400),
+      onBlink: context.update,
+    );
+
+    context.cursor = SystemMouseCursors.text;
+    context.update();
+  }
+
+  @override
+  void mouseDown(double x, double y) {
+    if (selectedShape.rect.contains(Offset(x, y))) {
+      _textCursor.changePosition(x);
+      _animationCursor.touch();
+      return;
+    }
+
+    _animationCursor.dispose();
+    super.mouseDown(x, y);
+  }
+
+  @override
+  void keyDown(KeyEvent keyEvent) {
+    _keyboardActions.keyDown(keyEvent);
+    _animationCursor.touch();
+  }
+
+  @override
+  void paint(Canvas canvas) {
+    context.paintStyle.paintSelectedText(selectedShape, canvas);
+    super.paint(canvas);
+
+    if (_animationCursor.isVisible) {
+      context.paintStyle.paintTextCursor(_textCursor, selectedShape, canvas);
+    }
+  }
+
+  @override
+  void onHover() {
+    if (hoverShape == selectedShape) {
+      context.cursor = SystemMouseCursors.text;
+    }
+  }
+
+  @override
+  void onMouseLeave() {
+    context.cursor = SystemMouseCursors.basic;
+  }
+
+  @override
+  String toString() {
+    return '${super.toString()} + Text Edit State';
+  }
+
+  final Offset _startPointer;
+  late final TextCursor _textCursor;
+  late final KeyboardActions _keyboardActions;
+  late final TextCursorAnimation _animationCursor;
+}
diff --git a/patterns/state/manipulator_state/states/selections/text_resize_state.dart b/patterns/state/manipulator_state/states/selections/text_resize_state.dart
new file mode 100644
index 0000000..c79e4cb
--- /dev/null
+++ b/patterns/state/manipulator_state/states/selections/text_resize_state.dart
@@ -0,0 +1,29 @@
+import 'dart:ui';
+
+import '../../shapes/text_shape.dart';
+import '../_/sub_states/parent_state.dart';
+import 'text_edit_state.dart';
+import 'text/text_size_marker_state.dart';
+
+class TextResizeState extends ParentState<TextShape> {
+  TextResizeState({required super.selectedShape}) {
+    addChildren([
+      TextSizeMarkerState(parentState: this),
+    ]);
+  }
+
+  @override
+  void mouseDoubleClick(double x, double y) {
+    context.changeState(
+      TextEditState(
+        startPointer: Offset(x, y),
+        selectedShape: selectedShape,
+      ),
+    );
+  }
+
+  @override
+  String toString() {
+    return '${super.toString()} + Text Resize State';
+  }
+}
diff --git a/patterns/state/manipulator_state/widgets/current_state.dart b/patterns/state/manipulator_state/widgets/current_state.dart
new file mode 100644
index 0000000..458c06d
--- /dev/null
+++ b/patterns/state/manipulator_state/widgets/current_state.dart
@@ -0,0 +1,45 @@
+import 'package:flutter/material.dart';
+
+import '../../../abstract_factory/tool_panel_factory/widgets/independent/event_listenable_builder.dart';
+import '../../../abstract_factory/tool_panel_factory/widgets/independent/panel.dart';
+import '../pattern/manipulator.dart';
+
+class CurrentState extends StatelessWidget {
+  final Manipulator manipulator;
+
+  const CurrentState({
+    Key? key,
+    required this.manipulator,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Positioned(
+      top: 12,
+      left: 300,
+      child: Panel(
+        thicknessHeight: 64,
+        direction: Axis.horizontal,
+        child: Padding(
+          padding: EdgeInsets.symmetric(horizontal: 16),
+          child: Center(
+            child: EventListenableBuilder(
+              event: manipulator.onStateChange,
+              builder: (context) {
+                return EventListenableBuilder(
+                  event: manipulator.onUpdate,
+                  builder: (context) {
+                    return Text(
+                      manipulator.toString(),
+                      style: TextStyle(color: Colors.white, fontSize: 16),
+                    );
+                  },
+                );
+              },
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/patterns/state/manipulator_state/widgets/drawing_board.dart b/patterns/state/manipulator_state/widgets/drawing_board.dart
new file mode 100644
index 0000000..2f25926
--- /dev/null
+++ b/patterns/state/manipulator_state/widgets/drawing_board.dart
@@ -0,0 +1,104 @@
+import 'package:flutter/material.dart';
+
+import '../../../abstract_factory/tool_panel_factory/widgets/independent/event_listenable_builder.dart';
+import '../app/app.dart';
+
+class DrawingBoard extends StatefulWidget {
+  final App app;
+
+  const DrawingBoard({Key? key, required this.app}) : super(key: key);
+
+  @override
+  State<DrawingBoard> createState() => _DrawingBoardState();
+}
+
+class _DrawingBoardState extends State<DrawingBoard> {
+  late FocusNode focusNode;
+  late Offset _lastMouseDown;
+
+  @override
+  void initState() {
+    focusNode = FocusNode(skipTraversal: true);
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return KeyboardListener(
+      autofocus: true,
+      focusNode: focusNode,
+      onKeyEvent: widget.app.manipulator.keyDown,
+      child: GestureDetector(
+        onDoubleTap: () => widget.app.manipulator.mouseDoubleClick(
+          _lastMouseDown.dx,
+          _lastMouseDown.dy,
+        ),
+        child: Listener(
+          onPointerDown: (e) {
+            _lastMouseDown = e.localPosition;
+            FocusScope.of(context).requestFocus(focusNode);
+            widget.app.manipulator.mouseDown(
+              e.localPosition.dx,
+              e.localPosition.dy,
+            );
+          },
+          onPointerHover: (e) => widget.app.manipulator.mouseMove(
+            e.localPosition.dx,
+            e.localPosition.dy,
+          ),
+          onPointerMove: (e) => widget.app.manipulator.mouseMove(
+            e.localPosition.dx,
+            e.localPosition.dy,
+          ),
+          onPointerUp: (e) => widget.app.manipulator.mouseUp(),
+          child: Container(
+            constraints: BoxConstraints.expand(),
+            color: Color(0xff1f1f1f),
+            child: EventListenableBuilder(
+              event: widget.app.shapes.onChange,
+              builder: (_) {
+                return EventListenableBuilder(
+                  event: widget.app.manipulator.onUpdate,
+                  builder: (_) {
+                    return MouseRegion(
+                      cursor: widget.app.manipulator.cursor,
+                      child: CustomPaint(
+                        painter: _Painter(widget.app),
+                      ),
+                    );
+                  },
+                );
+              },
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  @override
+  void dispose() {
+    focusNode.dispose();
+    super.dispose();
+  }
+}
+
+class _Painter extends CustomPainter {
+  final App app;
+
+  _Painter(this.app);
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    for (final shape in app.shapes) {
+      shape.paint(canvas);
+    }
+
+    app.manipulator.paint(canvas);
+  }
+
+  @override
+  bool shouldRepaint(covariant CustomPainter oldDelegate) {
+    return true;
+  }
+}
diff --git a/patterns/state/manipulator_state/widgets/tool_bar.dart b/patterns/state/manipulator_state/widgets/tool_bar.dart
new file mode 100644
index 0000000..b40adaf
--- /dev/null
+++ b/patterns/state/manipulator_state/widgets/tool_bar.dart
@@ -0,0 +1,63 @@
+import 'package:flutter/material.dart';
+
+import '../../../abstract_factory/tool_panel_factory/widgets/independent/event_listenable_builder.dart';
+import '../../../abstract_factory/tool_panel_factory/widgets/independent/panel.dart';
+import '../../../abstract_factory/tool_panel_factory/widgets/independent/tool_button.dart';
+import '../app/app.dart';
+import '../app/tool.dart';
+import '../states/free_sate.dart';
+import '../states/selections/selection_state.dart';
+
+class ToolBar extends StatelessWidget {
+  final App app;
+
+  const ToolBar({Key? key, required this.app}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Positioned(
+      top: 12,
+      left: 12,
+      child: Panel(
+        thicknessHeight: 64,
+        direction: Axis.horizontal,
+        child: EventListenableBuilder(
+          event: app.manipulator.onStateChange,
+          builder: (_) {
+            return Row(
+              children: [
+                for (final tool in app.tools) buildButton(tool),
+              ],
+            );
+          },
+        ),
+      ),
+    );
+  }
+
+  Widget buildButton(Tool tool) {
+    return ToolButton(
+      active: isSelected(tool),
+      icon: Center(child: tool.icon),
+      onTap: () {
+        app.manipulator.changeState(tool.state);
+      },
+    );
+  }
+
+  bool isSelected(Tool tool) {
+    final currentState = app.manipulator.state;
+
+    if (currentState is SelectionState) {
+      if (tool.state is FreeState) {
+        return true;
+      }
+    }
+
+    if (currentState.runtimeType == tool.state.runtimeType) {
+      return true;
+    }
+
+    return false;
+  }
+}
diff --git a/pubspec.yaml b/pubspec.yaml
index 1e9ed57..b24b6fd 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,21 +1,22 @@
 name: design_patterns_dart
 description: Dart examples for all classic GoF design patterns.
-version: 0.23.14
+version: 0.24.0
 homepage: https://refactoring.guru/design-patterns
 repository: https://github.com/RefactoringGuru/design-patterns-dart
 issue_tracker: https://github.com/RefactoringGuru/design-patterns-dart/issue
 
 environment:
-  sdk: '>=2.15.0-68.0.dev <3.0.0'
+  sdk: ">=2.17.0 <3.0.0"
 
 dependencies:
   collection: ^1.15.0
   flutter:
     sdk: flutter
   cupertino_icons: ^1.0.2
+  material_design_icons_flutter: ^5.0.6595
   
 dev_dependencies:
-  lints: ^1.0.0
+  flutter_lints: ^2.0.0
 
 flutter:
   uses-material-design: true