Return all files in folder.

def next(self):
        """
        Return all files in folder.
        """
        # get depth of starting root directory
        base_depth = self.__root.count(os.path.sep)

        # walk files and folders
        for root, subFolders, files in os.walk(self.__root):

            # apply folder filter
            if not self.filter_folder(root):
                continue

            # make sure we don't pass depth limit
            if self.__depth_limit is not None:
                curr_depth = root.count(os.path.sep)
                if curr_depth - base_depth > self.__depth_limit:
                    continue

            # if need to return folders return it
            if self.__ret_folders:
                yield root

            # return files
            if self.__ret_files:
                for f in files:
                    yield os.path.join(root, f)

        # end iterator
        raise StopIteration