private void TargetFilter_TextChanged(object sender, TextChangedEventArgs e)
        {
            if (RegexSearchMethod == true && (!TmxHandler.IsValidRegex(SourceFilterString) || !TmxHandler.IsValidRegex(TargetFilterString)))
            {
                return;
            }
            var workingCollection = FilterBaseCollection;

            MainCollection = TmxHandler.FilterCollection(workingCollection, SourceFilterString, TargetFilterString, RegexSearchMethod);
        }
        private async void LoadButton_Click(object sender, RoutedEventArgs e)
        {
            List <string> newList;

            try
            {
                newList = TmxHandler.GetFileList(SelectedPath);
            }
            catch (Exception)
            {
// dodaj message boxa ktory wyswietli error.
                return;
            }

            await Task.Run(() => MainCollection = TmxHandler.ReadTmxData(newList));

            FilterBaseCollection = MainCollection;
        }