feat: Added Widget system.

packages/katana_cli/lib/command/code/code.dart

@@ -19,6 +19,9 @@ part 'value.dart';
 part 'redirect_query.dart';
 part 'boot.dart';
 part 'prefs.dart';
+part 'widget.dart';
+part 'stateless.dart';
+part 'stateful.dart';
 
 class CodeCliCommand extends CliCommandGroup {
   const CodeCliCommand();
@@ -41,5 +44,8 @@ class CodeCliCommand extends CliCommandGroup {
         "value": CodeValueCliCommand(),
         "redirect": CodeRedirectQueryCliCommand(),
         "prefs": CodePrefsCliCommand(),
+        "widget": CodeWidgetCliCommand(),
+        "stateless": CodeStatelessCliCommand(),
+        "stateful": CodeStatefulCliCommand(),
       };
 }

packages/katana_cli/lib/command/code/redirect_query.dart

@@ -27,7 +27,7 @@ class CodeRedirectQueryCliCommand extends CliCodeCommand {
     final path = context.args.get(2, "");
     if (path.isEmpty) {
       error(
-        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code page [path]\r\n",
+        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code redirect [path]\r\n",
       );
       return;
     }

packages/katana_cli/lib/command/code/stateful.dart

@@ -0,0 +1,83 @@
+part of katana_cli.code;
+
+/// Create a base class to create a StatefulWidget.
+///
+/// StatefulWidgetを作成するベースクラスを作成します。
+class CodeStatefulCliCommand extends CliCodeCommand {
+  /// Create a base class to create a StatefulWidget.
+  ///
+  /// StatefulWidgetを作成するベースクラスを作成します。
+  const CodeStatefulCliCommand();
+
+  @override
+  String get name => "stateful";
+
+  @override
+  String get prefix => "stateful";
+
+  @override
+  String get directory => "lib/widgets";
+
+  @override
+  String get description =>
+      "Create a StatefulWidget in `$directory/(filepath).dart`. StatefulWidgetを`$directory/(filepath).dart`に作成します。";
+
+  @override
+  Future<void> exec(ExecContext context) async {
+    final path = context.args.get(2, "");
+    if (path.isEmpty) {
+      error(
+        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code stateful [path]\r\n",
+      );
+      return;
+    }
+    label("Create a StatefulWidget class in `$directory/$path.dart`.");
+    await generateDartCode("$directory/$path");
+  }
+
+  @override
+  String import(String path, String baseName, String className) {
+    return """
+// ignore: unused_import, unnecessary_import
+import 'package:flutter/material.dart';
+// ignore: unused_import, unnecessary_import
+import 'package:masamune/masamune.dart';
+
+// ignore: unused_import, unnecessary_import
+import '/main.dart';
+""";
+  }
+
+  @override
+  String header(String path, String baseName, String className) {
+    return """
+""";
+  }
+
+  @override
+  String body(String path, String baseName, String className) {
+    return """
+/// StatefulWidget.
+@immutable
+class ${className}Widget extends StatefulWidget {
+  const ${className}Widget({
+    super.key,
+    // TODO: Set parameters for the widget.
+    \${1}
+  });
+
+  @override
+  State<StatefulWidget> createState() => _${className}State();
+}
+
+class _${className}State extends State<${className}Widget> {
+  @override
+  Widget build(BuildContext context) {
+    // Describes the structure of the widget.
+    // TODO: Implement the view.
+    return \${2:Empty()};
+  }
+}
+""";
+  }
+}

packages/katana_cli/lib/command/code/stateless.dart

@@ -0,0 +1,78 @@
+part of katana_cli.code;
+
+/// Create a base class to create a StatelessWidget.
+///
+/// StatelessWidgetを作成するベースクラスを作成します。
+class CodeStatelessCliCommand extends CliCodeCommand {
+  /// Create a base class to create a StatelessWidget.
+  ///
+  /// StatelessWidgetを作成するベースクラスを作成します。
+  const CodeStatelessCliCommand();
+
+  @override
+  String get name => "stateless";
+
+  @override
+  String get prefix => "stateless";
+
+  @override
+  String get directory => "lib/widgets";
+
+  @override
+  String get description =>
+      "Create a StatelessWidget in `$directory/(filepath).dart`. StatelessWidgetを`$directory/(filepath).dart`に作成します。";
+
+  @override
+  Future<void> exec(ExecContext context) async {
+    final path = context.args.get(2, "");
+    if (path.isEmpty) {
+      error(
+        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code stateless [path]\r\n",
+      );
+      return;
+    }
+    label("Create a StatelessWidget class in `$directory/$path.dart`.");
+    await generateDartCode("$directory/$path");
+  }
+
+  @override
+  String import(String path, String baseName, String className) {
+    return """
+// ignore: unused_import, unnecessary_import
+import 'package:flutter/material.dart';
+// ignore: unused_import, unnecessary_import
+import 'package:masamune/masamune.dart';
+
+// ignore: unused_import, unnecessary_import
+import '/main.dart';
+""";
+  }
+
+  @override
+  String header(String path, String baseName, String className) {
+    return """
+""";
+  }
+
+  @override
+  String body(String path, String baseName, String className) {
+    return """
+/// StatelessWidget.
+@immutable
+class ${className}Widget extends StatelessWidget {
+  const ${className}Widget({
+    super.key,
+    // TODO: Set parameters for the widget.
+    \${1}
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    // Describes the structure of the widget.
+    // TODO: Implement the view.
+    return \${2:Empty()};
+  }
+}
+""";
+  }
+}

packages/katana_cli/lib/command/code/tmp/basic.dart

@@ -27,7 +27,7 @@ class CodeTmpBasicCliCommand extends CliCodeCommand {
     final path = context.args.get(3, "");
     if (path.isEmpty) {
       error(
-        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code tmp form [path]\r\n",
+        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code tmp basic [path]\r\n",
       );
       return;
     }

packages/katana_cli/lib/command/code/value.dart

@@ -27,7 +27,7 @@ class CodeValueCliCommand extends CliCodeCommand {
     final path = context.args.get(2, "");
     if (path.isEmpty) {
       error(
-        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code page [path]\r\n",
+        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code value [path]\r\n",
       );
       return;
     }

packages/katana_cli/lib/command/code/widget.dart

@@ -0,0 +1,83 @@
+part of katana_cli.code;
+
+/// Create a base class to create a ScopedWidget.
+///
+/// ScopedWidgetを作成するベースクラスを作成します。
+class CodeWidgetCliCommand extends CliCodeCommand {
+  /// Create a base class to create a ScopedWidget.
+  ///
+  /// ScopedWidgetを作成するベースクラスを作成します。
+  const CodeWidgetCliCommand();
+
+  @override
+  String get name => "widget";
+
+  @override
+  String get prefix => "widget";
+
+  @override
+  String get directory => "lib/widgets";
+
+  @override
+  String get description =>
+      "Create a ScopedWidget in `$directory/(filepath).dart`. ScopedWidgetを`$directory/(filepath).dart`に作成します。";
+
+  @override
+  Future<void> exec(ExecContext context) async {
+    final path = context.args.get(2, "");
+    if (path.isEmpty) {
+      error(
+        "[path] is not specified. Please enter [path] according to the following command.\r\nkatana code widget [path]\r\n",
+      );
+      return;
+    }
+    label("Create a ScopedWidget class in `$directory/$path.dart`.");
+    await generateDartCode("$directory/$path");
+  }
+
+  @override
+  String import(String path, String baseName, String className) {
+    return """
+// ignore: unused_import, unnecessary_import
+import 'package:flutter/material.dart';
+// ignore: unused_import, unnecessary_import
+import 'package:masamune/masamune.dart';
+
+// ignore: unused_import, unnecessary_import
+import '/main.dart';
+""";
+  }
+
+  @override
+  String header(String path, String baseName, String className) {
+    return """
+""";
+  }
+
+  @override
+  String body(String path, String baseName, String className) {
+    return """
+/// ScopedWidget.
+@immutable
+class ${className}Widget extends ScopedWidget {
+  const ${className}Widget({
+    super.key,
+    // TODO: Set parameters for the widget.
+    \${1}
+  });
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Describes the process of loading
+    // and defining variables required for the widget.
+    // TODO: Implement the variable loading process.
+    \${2}
+
+    // Describes the structure of the widget.
+    // TODO: Implement the view.
+    return \${3:Empty()};
+  }
+}
+""";
+  }
+}

packages/katana_cli/pubspec.lock

@@ -109,10 +109,10 @@ packages:
     dependency: "direct main"
     description:
       name: image
-      sha256: "1f9ecf99b08c92dedb699de1d28549f5d79b4423b48cf3f95d6968156db5dd67"
+      sha256: "3686865febd85c57a632d87a0fb1f0a8a9ef602fdb68d909c3e9aa29ec70fd24"
       url: "https://pub.dev"
     source: hosted
-    version: "4.0.12"
+    version: "4.0.13"
   import_sorter:
     dependency: "direct dev"
     description:
@@ -157,10 +157,10 @@ packages:
     dependency: transitive
     description:
       name: meta
-      sha256: "6c268b42ed578a53088d834796959e4a1814b5e9e164f147f580a386e5decf42"
+      sha256: "12307e7f0605ce3da64cf0db90e5fcab0869f3ca03f76be6bb2991ce0a55e82b"
       url: "https://pub.dev"
     source: hosted
-    version: "1.8.0"
+    version: "1.9.0"
   path:
     dependency: transitive
     description: