fetchSpellCheckSuggestions method

Implementation

@override
Future<List<SuggestionSpan>?> fetchSpellCheckSuggestions(
    Locale locale, String text) async {

  final List<dynamic> rawResults;
  final String languageTag = locale.toLanguageTag();

  try {
    rawResults = await spellCheckChannel.invokeMethod(
      'SpellCheck.initiateSpellCheck',
      <String>[languageTag, text],
    ) as List<dynamic>;
  } catch (e) {
    // Spell check request canceled due to pending request.
    return null;
  }

  List<SuggestionSpan> suggestionSpans = <SuggestionSpan>[
    for (final Map<dynamic, dynamic> resultMap in rawResults.cast<Map<dynamic, dynamic>>())
      SuggestionSpan(
        TextRange(start: resultMap['startIndex'] as int, end: resultMap['endIndex'] as int),
        (resultMap['suggestions'] as List<Object?>).cast<String>(),
      ),
  ];

  if (lastSavedResults != null) {
    // Merge current and previous spell check results if between requests,
    // the text has not changed but the spell check results have.
    final bool textHasNotChanged = lastSavedResults!.spellCheckedText == text;
    final bool spansHaveChanged =
        listEquals(lastSavedResults!.suggestionSpans, suggestionSpans);

    if (textHasNotChanged && spansHaveChanged) {
      suggestionSpans = mergeResults(lastSavedResults!.suggestionSpans, suggestionSpans);
    }
  }
  lastSavedResults = SpellCheckResults(text, suggestionSpans);

  return suggestionSpans;
}