update method

Implementation

@override
(SuggestModel, Cmd?) update(Msg msg) {
  if (msg is! KeyMsg) return (this, null);
  final key = msg.key;

  // Cancel
  if (keyMatches(key, [keyMap.cancel])) {
    return (this, Cmd.message(const SuggestCancelledMsg()));
  }

  // Accept
  if (keyMatches(key, [keyMap.accept])) {
    final value = _acceptedValue();
    return (this, Cmd.message(SuggestSubmittedMsg(value)));
  }

  // Navigate up / down
  if (keyMatches(key, [keyMap.moveDown])) {
    _moveHighlight(1);
    return (this, null);
  }
  if (keyMatches(key, [keyMap.moveUp])) {
    _moveHighlight(-1);
    return (this, null);
  }
  if (keyMatches(key, [keyMap.moveFirst])) {
    if (_highlighted >= 0) {
      _highlighted = 0;
      _firstVisible = 0;
    }
    return (this, null);
  }
  if (keyMatches(key, [keyMap.moveLast])) {
    if (_highlighted >= 0) {
      final m = matches;
      if (m.isNotEmpty) {
        _highlighted = m.length - 1;
        _firstVisible = (m.length - scroll).clamp(0, m.length - 1);
      }
    }
    return (this, null);
  }

  // Left / Right arrows clear the highlight but don't consume the key
  // (future: cursor movement within the input)
  if (keyMatches(key, [keyMap.moveCursorLeft])) {
    _highlighted = -1;
    if (_cursor > 0) _cursor--;
    return (this, null);
  }
  if (keyMatches(key, [keyMap.moveCursorRight])) {
    _highlighted = -1;
    final graphemes = uni.graphemes(_rawInput).toList();
    if (_cursor < graphemes.length) _cursor++;
    return (this, null);
  }

  // Backspace
  if (keyMatches(key, [keyMap.deleteBackward])) {
    _highlighted = -1;
    if (_rawInput.isNotEmpty) {
      final gs = uni.graphemes(_rawInput).toList();
      if (_cursor > 0) {
        gs.removeAt(_cursor - 1);
        _rawInput = gs.join();
        _cursor--;
      }
    }
    _firstVisible = 0;
    return (this, null);
  }

  // Character input
  if (key.runes.isNotEmpty) {
    final ch = String.fromCharCodes(key.runes);
    _highlighted = -1;
    final gs = uni.graphemes(_rawInput).toList();
    gs.insert(_cursor, ch);
    _rawInput = gs.join();
    _cursor++;
    _firstVisible = 0;
    return (this, null);
  }

  return (this, null);
}