def _pre_render(self):
        # split markup, words, and lines
        # result: list of word with position and width/height
        # during the first pass, we don't care about h/valign
        self._cached_lines = lines = []
        self._refs = {}
        self._anchors = {}
        clipped = False
        w = h = 0
        uw, uh = self.text_size
        spush = self._push_style
        spop = self._pop_style
        opts = options = self.options
        options['_ref'] = None
        options['_anchor'] = None
        options['script'] = 'normal'
        shorten = options['shorten']
        # if shorten, then don't split lines to fit uw, because it will be
        # flattened later when shortening and broken up lines if broken
        # mid-word will have space mid-word when lines are joined
        uw_temp = None if shorten else uw
        xpad = options['padding_x']
        uhh = (None if uh is not None and options['valign'] != 'top' or
               options['shorten'] else uh)
        options['strip'] = options['strip'] or options['halign'] == 'justify'
        for item in self.markup:
            if item == '[b]':
                spush('bold')
                options['bold'] = True
                self.resolve_font_name()
            elif item == '[/b]':
                spop('bold')
                self.resolve_font_name()
            elif item == '[i]':
                spush('italic')
                options['italic'] = True
                self.resolve_font_name()
            elif item == '[/i]':
                spop('italic')
                self.resolve_font_name()
            elif item == '[u]':
                spush('underline')
                options['underline'] = True
                self.resolve_font_name()
            elif item == '[/u]':
                spop('underline')
                self.resolve_font_name()
            elif item == '[s]':
                spush('strikethrough')
                options['strikethrough'] = True
                self.resolve_font_name()
            elif item == '[/s]':
                spop('strikethrough')
                self.resolve_font_name()
            elif item[:6] == '[size=':
                item = item[6:-1]
                try:
                    if item[-2:] in ('px', 'pt', 'in', 'cm', 'mm', 'dp', 'sp'):
                        size = dpi2px(item[:-2], item[-2:])
                    else:
                        size = int(item)
                except __HOLE__:
                    raise
                    size = options['font_size']
                spush('font_size')
                options['font_size'] = size
            elif item == '[/size]':
                spop('font_size')
            elif item[:7] == '[color=':
                color = parse_color(item[7:-1])
                spush('color')
                options['color'] = color
            elif item == '[/color]':
                spop('color')
            elif item[:6] == '[font=':
                fontname = item[6:-1]
                spush('font_name')
                options['font_name'] = fontname
                self.resolve_font_name()
            elif item == '[/font]':
                spop('font_name')
                self.resolve_font_name()
            elif item[:5] == '[sub]':
                spush('font_size')
                spush('script')
                options['font_size'] = options['font_size'] * .5
                options['script'] = 'subscript'
            elif item == '[/sub]':
                spop('font_size')
                spop('script')
            elif item[:5] == '[sup]':
                spush('font_size')
                spush('script')
                options['font_size'] = options['font_size'] * .5
                options['script'] = 'superscript'
            elif item == '[/sup]':
                spop('font_size')
                spop('script')
            elif item[:5] == '[ref=':
                ref = item[5:-1]
                spush('_ref')
                options['_ref'] = ref
            elif item == '[/ref]':
                spop('_ref')
            elif not clipped and item[:8] == '[anchor=':
                options['_anchor'] = item[8:-1]
            elif not clipped:
                item = item.replace('&bl;', '[').replace(
                    '&br;', ']').replace('&amp;', '&')
                opts = copy(options)
                extents = self.get_cached_extents()
                opts['space_width'] = extents(' ')[0]
                w, h, clipped = layout_text(item, lines, (w, h),
                    (uw_temp, uhh), opts, extents, True, False)

        if len(lines):  # remove any trailing spaces from the last line
            old_opts = self.options
            self.options = copy(opts)
            w, h, clipped = layout_text('', lines, (w, h), (uw_temp, uhh),
                self.options, self.get_cached_extents(), True, True)
            self.options = old_opts

        if shorten:
            options['_ref'] = None  # no refs for you!
            options['_anchor'] = None
            w, h, lines = self.shorten_post(lines, w, h)
            self._cached_lines = lines
        # when valign is not top, for markup we layout everything (text_size[1]
        # is temporarily set to None) and after layout cut to size if too tall
        elif uh != uhh and h > uh and len(lines) > 1:
            if options['valign'] == 'bottom':
                i = 0
                while i < len(lines) - 1 and h > uh:
                    h -= lines[i].h
                    i += 1
                del lines[:i]
            else:  # middle
                i = 0
                top = int(h / 2. + uh / 2.)  # remove extra top portion
                while i < len(lines) - 1 and h > top:
                    h -= lines[i].h
                    i += 1
                del lines[:i]
                i = len(lines) - 1  # remove remaining bottom portion
                while i and h > uh:
                    h -= lines[i].h
                    i -= 1
                del lines[i + 1:]

        # now justify the text
        if options['halign'] == 'justify' and uw is not None:
            # XXX: update refs to justified pos
            # when justify, each line should've been stripped already
            split = partial(re.split, re.compile('( +)'))
            uww = uw - 2 * xpad
            chr = type(self.text)
            space = chr(' ')
            empty = chr('')

            for i in range(len(lines)):
                line = lines[i]
                words = line.words
                # if there's nothing to justify, we're done
                if (not line.w or int(uww - line.w) <= 0 or not len(words) or
                    line.is_last_line):
                    continue

                done = False
                parts = [None, ] * len(words)  # contains words split by space
                idxs = [None, ] * len(words)  # indices of the space in parts
                # break each word into spaces and add spaces until it's full
                # do first round of split in case we don't need to split all
                for w in range(len(words)):
                    word = words[w]
                    sw = word.options['space_width']
                    p = parts[w] = split(word.text)
                    idxs[w] = [v for v in range(len(p)) if
                               p[v].startswith(' ')]
                    # now we have the indices of the spaces in split list
                    for k in idxs[w]:
                        # try to add single space at each space
                        if line.w + sw > uww:
                            done = True
                            break
                        line.w += sw
                        word.lw += sw
                        p[k] += space
                    if done:
                        break

                # there's not a single space in the line?
                if not any(idxs):
                    continue

                # now keep adding spaces to already split words until done
                while not done:
                    for w in range(len(words)):
                        if not idxs[w]:
                            continue
                        word = words[w]
                        sw = word.options['space_width']
                        p = parts[w]
                        for k in idxs[w]:
                            # try to add single space at each space
                            if line.w + sw > uww:
                                done = True
                                break
                            line.w += sw
                            word.lw += sw
                            p[k] += space
                        if done:
                            break

                # if not completely full, push last words to right edge
                diff = int(uww - line.w)
                if diff > 0:
                    # find the last word that had a space
                    for w in range(len(words) - 1, -1, -1):
                        if not idxs[w]:
                            continue
                        break
                    old_opts = self.options
                    self.options = word.options
                    word = words[w]
                    # split that word into left/right and push right till uww
                    l_text = empty.join(parts[w][:idxs[w][-1]])
                    r_text = empty.join(parts[w][idxs[w][-1]:])
                    left = LayoutWord(word.options,
                        self.get_extents(l_text)[0], word.lh, l_text)
                    right = LayoutWord(word.options,
                        self.get_extents(r_text)[0], word.lh, r_text)
                    left.lw = max(left.lw, word.lw + diff - right.lw)
                    self.options = old_opts

                    # now put words back together with right/left inserted
                    for k in range(len(words)):
                        if idxs[k]:
                            words[k].text = empty.join(parts[k])
                    words[w] = right
                    words.insert(w, left)
                else:
                    for k in range(len(words)):
                        if idxs[k]:
                            words[k].text = empty.join(parts[k])
                line.w = uww
                w = max(w, uww)

        self._internal_size = w, h
        if uw:
            w = uw
        if uh:
            h = uh
        if h > 1 and w < 2:
            w = 2
        if w < 1:
            w = 1
        if h < 1:
            h = 1
        return int(w), int(h)
dataset/ETHPy150Open kivy/kivy/kivy/core/text/markup.py/MarkupLabel._pre_render