class GameListUI(object):

    @staticmethod
    def from_database(**kwargs):
        all_games = []
        for library_id, library_name in database.queryLibrary():
            games = database.queryOrganicGames(library_id, 'libraryname.name', True)
            all_games.extend(games)
        return GameListUI(game_list=all_games, **kwargs)

    def __init__(self, **kwargs):
        self.game_list = kwargs['game_list']
        self.bound_rect = kwargs['bound_rect']
        self.start_x, self.start_y, self.end_x, self.end_y = self.bound_rect
        self.width = self.end_x - self.start_x
        self.height = self.end_y - self.start_y
        self.max_visible_games = 4
        self.horizontal_gap = 10
        self.vertical_gap = 10
        self.selected_index = 0
        self.line_height = (self.height - ((self.max_visible_games-1) * self.vertical_gap)) / self.max_visible_games

    def scroll(self, offset):
        self.selected_index += offset
        if self.selected_index < 0:
            self.selected_index = 0
        elif self.selected_index >= len(self.game_list):
            self.selected_index = len(self.game_list) - 1
        print(self.selected_index)

    def render(self):
        for curr_index, game in enumerate(self.game_list[self.selected_index:self.selected_index+self.max_visible_games]):
            curr_pos_y = self.start_y + (self.line_height + self.vertical_gap) * curr_index
            picture = pygame.image.load('mame/snap/{}'.format(game['picture']))
            big_pic = pygame.transform.scale(picture, (self.line_height, self.line_height))
            rect_pic = big_pic.get_rect(topleft=(self.start_x, curr_pos_y))
            screen.blit(big_pic, rect_pic)