private void ClearKeywords()
 {
     TitleKeywords.Clear();
     AuthorKeywords.Clear();
     ParodyKeywords.Clear();
     CharacterKeywords.Clear();
     TagKeywords.Clear();
 }
        private void ApplyAdvancedSearch()
        {
            DoujinsModel.FilteredDoujinsView.Filter = new Predicate <object>(o =>
            {
                Doujin doujin = ((Doujin)o);

                return(TitleKeywords.All(doujin.Title.ToLower().Contains) &&
                       AuthorKeywords.All(doujin.Author.ToLower().Contains) &&
                       ParodyKeywords.All(doujin.Parodies.ToLower().Contains) &&
                       CharacterKeywords.All(doujin.Characters.ToLower().Contains) &&
                       TagKeywords.All(doujin.Tags.ToLower().Contains));
            });
        }