✨ Keyboard navigation basis

lib/widgets/keyboard_navigation.dart

@@ -0,0 +1,86 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+enum VimMode { normal, insert }
+
+class KeyboardNavigation extends StatefulWidget {
+  const KeyboardNavigation({super.key, required this.child});
+
+  final Widget child;
+
+  @override
+  State<KeyboardNavigation> createState() => _KeyboardNavigationState();
+}
+
+class _KeyboardNavigationState extends State<KeyboardNavigation> {
+  VimMode _mode = VimMode.normal;
+  final FocusScopeNode _focusScopeNode = FocusScopeNode();
+
+  @override
+  void dispose() {
+    _focusScopeNode.dispose();
+    super.dispose();
+  }
+
+  KeyEventResult _handleKeyEvent(FocusNode node, KeyEvent event) {
+    if (event is! KeyDownEvent && event is! KeyRepeatEvent) {
+      return KeyEventResult.ignored;
+    }
+
+    if (_mode == VimMode.normal) {
+      if (event.logicalKey == LogicalKeyboardKey.keyJ) {
+        node.focusInDirection(TraversalDirection.down);
+        return KeyEventResult.handled;
+      } else if (event.logicalKey == LogicalKeyboardKey.keyK) {
+        node.focusInDirection(TraversalDirection.up);
+        return KeyEventResult.handled;
+      } else if (event.logicalKey == LogicalKeyboardKey.keyH) {
+        final focusNode = FocusManager.instance.primaryFocus;
+        if (focusNode != null) {
+          final scrollable = Scrollable.of(focusNode.context!);
+          if (scrollable.position.axis == Axis.horizontal) {
+            scrollable.position.moveTo(scrollable.position.pixels - 50);
+            return KeyEventResult.handled;
+          }
+        }
+        node.focusInDirection(TraversalDirection.left);
+        return KeyEventResult.handled;
+      } else if (event.logicalKey == LogicalKeyboardKey.keyL) {
+        final focusNode = FocusManager.instance.primaryFocus;
+        if (focusNode != null) {
+          final scrollable = Scrollable.of(focusNode.context!);
+          if (scrollable.position.axis == Axis.horizontal) {
+            scrollable.position.moveTo(scrollable.position.pixels + 50);
+            return KeyEventResult.handled;
+          }
+        }
+        node.focusInDirection(TraversalDirection.right);
+        return KeyEventResult.handled;
+      } else if (event.logicalKey == LogicalKeyboardKey.keyI) {
+        setState(() {
+          _mode = VimMode.insert;
+        });
+        return KeyEventResult.handled;
+      }
+    } else if (_mode == VimMode.insert) {
+      if (event.logicalKey == LogicalKeyboardKey.escape) {
+        setState(() {
+          _mode = VimMode.normal;
+        });
+        // Unfocus the current widget to prevent typing
+        node.unfocus();
+        return KeyEventResult.handled;
+      }
+    }
+    return KeyEventResult.ignored;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Focus(
+      focusNode: _focusScopeNode,
+      onKeyEvent: _handleKeyEvent,
+      child: widget.child,
+    );
+  }
+}