feat(terminal): use platform-native copy and paste shortcuts (#15931)

flutter/lib/models/terminal_copy_shortcut.dart

@@ -0,0 +1,66 @@
+import 'dart:async';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/widgets.dart';
+import 'package:xterm/xterm.dart';
+
+const _controlShiftVPasteShortcut = SingleActivator(
+  LogicalKeyboardKey.keyV,
+  control: true,
+  shift: true,
+);
+
+Future<void> writeTerminalClipboard(String text) async {
+  try {
+    await Clipboard.setData(ClipboardData(text: text));
+  } catch (error) {
+    debugPrint('[Terminal] Failed to write clipboard: $error');
+  }
+}
+
+Map<ShortcutActivator, Intent>? platformTerminalShortcuts() {
+  if (defaultTargetPlatform != TargetPlatform.linux) return null;
+  return {
+    for (final entry in defaultTerminalShortcuts.entries)
+      if (!_isControlVShortcut(entry.key)) entry.key: entry.value,
+    _controlShiftVPasteShortcut:
+        const PasteTextIntent(SelectionChangedCause.keyboard),
+  };
+}
+
+bool _isControlVShortcut(ShortcutActivator shortcut) =>
+    shortcut is SingleActivator &&
+    shortcut.trigger == LogicalKeyboardKey.keyV &&
+    shortcut.control &&
+    !shortcut.shift &&
+    !shortcut.alt &&
+    !shortcut.meta;
+
+FocusOnKeyEventCallback terminalCopyHandler(
+  Terminal terminal,
+  TerminalController controller,
+) =>
+    (_, event) {
+      if (!_isWindowsCopyShortcut(event)) return KeyEventResult.ignored;
+      final selection = controller.selection;
+      if (selection == null || selection.isCollapsed) {
+        return KeyEventResult.ignored;
+      }
+      if (event is KeyDownEvent) {
+        final text = terminal.buffer.getText(selection);
+        unawaited(writeTerminalClipboard(text));
+      }
+      return KeyEventResult.handled;
+    };
+
+bool _isWindowsCopyShortcut(KeyEvent event) {
+  final keyboard = HardwareKeyboard.instance;
+  return defaultTargetPlatform == TargetPlatform.windows &&
+      (event is KeyDownEvent || event is KeyRepeatEvent) &&
+      event.logicalKey == LogicalKeyboardKey.keyC &&
+      keyboard.isControlPressed &&
+      !keyboard.isShiftPressed &&
+      !keyboard.isAltPressed &&
+      !keyboard.isMetaPressed;
+}

flutter/lib/models/terminal_mouse_handler.dart

@@ -4,6 +4,7 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/widgets.dart';
 import 'package:xterm/xterm.dart';
 
+import 'terminal_copy_shortcut.dart';
 import 'terminal_mouse_drag_reporter.dart';
 
 /// xterm 4.0.0 encodes wheel buttons as 68..71; the extra bit reads as a Shift
@@ -291,6 +292,8 @@ class _TerminalMouseInteractionState extends State<TerminalMouseInteraction> {
         focusNode: widget.focusNode,
         backgroundOpacity: widget.backgroundOpacity,
         padding: widget.padding,
+        shortcuts: platformTerminalShortcuts(),
+        onKeyEvent: terminalCopyHandler(widget.terminal, widget.controller),
         onSecondaryTapDown: widget.onSecondaryTapDown,
       ),
     );