opt. proj struct

lib/data/provider/virtual_keyboard.dart

@@ -0,0 +1,29 @@
+import 'package:flutter/widgets.dart';
+import 'package:xterm/core.dart';
+
+class VirtualKeyboard extends TerminalInputHandler with ChangeNotifier {
+  VirtualKeyboard();
+
+  bool ctrl = false;
+  bool alt = false;
+
+  void reset(TerminalKeyboardEvent e) {
+    if (e.ctrl) {
+      ctrl = false;
+    }
+    if (e.alt) {
+      alt = false;
+    }
+    notifyListeners();
+  }
+
+  @override
+  String? call(TerminalKeyboardEvent event) {
+    final e = event.copyWith(
+      ctrl: event.ctrl || ctrl,
+      alt: event.alt || alt,
+    );
+    reset(e);
+    return defaultInputHandler.call(e);
+  }
+}