public TilesetImporterViewModel(TilesetDocument tileset)
        {
            _importer = new TilesetImporter(tileset);
            SetTileset(tileset);
            ImportImagesCommand = new RelayCommand(x => ImportImages());
            ExtractCommand = new RelayCommand(x => ExtractImages());
            CompactSheetCommand = new RelayCommand(x => CompactSheet());

            RefreshSheet();
        }
 protected override void SetTileset(TilesetDocument tileset)
 {
     base.SetTileset(tileset);
     _importer = new TilesetImporter(tileset);
     RefreshSheet();
 }