call method

@override String? call(TerminalKeyboardEvent event)

Implementation

@override
String? call(TerminalKeyboardEvent event) {
  if (event.type == TerminalKeyEventType.release) {
    return null;
  }
  if (!event.alt || event.ctrl || event.superKey) {
    return null;
  }
  if (event.platform == TerminalTargetPlatform.macos) {
    if (!event.state.altSendsEscapeMode) return null;
  } else {
    if (!event.state.altEscPrefixMode) return null;
  }

  final text = _legacyText(event);
  if (text == null) return null;

  // `_legacyText` only ever returns a single code point, so this cannot
  // be null - the `!` keeps that contract visible instead of silently
  // widening it.
  final codePoint = singleCodePoint(text)!;
  if (codePoint > 0x7f) return text;
  return '\x1b$text';
}