__init__.py

Requirement =====================================================================================

    literal_block = 0

    def visit_literal_block(self, node):
        self.literal_block = 1

    def depart_literal_block(self, node):
        self.literal_block = 0

    visit_doctest_block = visit_literal_block
    depart_doctest_block = depart_literal_block

    inline_literal = 0

    def visit_literal(self, node):
        self.inline_literal += 1

    def depart_literal(self, node):
        self.inline_literal -= 1

    def visit_comment(self, node):
        self.append('\n'.join(['% ' + line for line
                               in node.astext().splitlines(0)]), newline='\n')
        raise nodes.SkipChildren

    def before_topic(self, node):
        if 'contents' in node['classes']:
            for bullet_list in list(node.traverse(nodes.bullet_list)):
                p = bullet_list.parent
                if isinstance(p, nodes.list_item):
                    p.parent.insert(p.parent.index(p) + 1, bullet_list)
                    del p[1]
            for paragraph in node.traverse(nodes.paragraph):
                paragraph.attributes.update(paragraph[0].attributes)
                paragraph[:] = paragraph[0]
                paragraph.parent['tocrefid'] = paragraph['refid']
            node['contents'] = 1
        else:
            node['contents'] = 0

    bullet_list_level = 0

    def visit_bullet_list(self, node):
        self.append(r'\Dsetbullet{\labelitem%s}' %
                    ['i', 'ii', 'iii', 'iv'][min(self.bullet_list_level, 3)])
        self.bullet_list_level += 1

    def depart_bullet_list(self, node):
        self.bullet_list_level -= 1

    enum_styles = {'arabic': 'arabic', 'loweralpha': 'alph', 'upperalpha':
                   'Alph', 'lowerroman': 'roman', 'upperroman': 'Roman'}

    enum_counter = 0

    def visit_enumerated_list(self, node):
        # We create our own enumeration list environment.  This allows
        # to set the style and starting value and unlimited nesting.
        # Maybe this can be moved to the stylesheet?
        self.enum_counter += 1
        enum_prefix = self.encode(node['prefix'])
        enum_suffix = self.encode(node['suffix'])
        enum_type = '\\' + self.enum_styles.get(node['enumtype'], r'arabic')
        start = node.get('start', 1) - 1
        counter = 'Denumcounter%d' % self.enum_counter
        self.append(r'\Dmakeenumeratedlist{%s}{%s}{%s}{%s}{%s}{'
                    % (enum_prefix, enum_type, enum_suffix, counter, start))
                    # for Emacs: }

    def depart_enumerated_list(self, node):
        self.append('}')  # for Emacs: {

    def before_list_item(self, node):
        # XXX needs cleanup.
        if (len(node) and (isinstance(node[-1], nodes.TextElement) or
                           isinstance(node[-1], nodes.Text)) and
            node.parent.index(node) == len(node.parent) - 1):
            node['lastitem'] = 'true'

    before_line = before_list_item

    def before_raw(self, node):
        if 'latex' in node.get('format', '').split():
            # We're inserting the text in before_raw and thus outside
            # of \DN... and \Dattr in order to make grouping with
            # curly brackets work.
            self.append(node.astext())
        raise nodes.SkipChildren

    def process_backlinks(self, node, type):
        self.append(r'\renewcommand{\Dsinglebackref}{}')
        self.append(r'\renewcommand{\Dmultiplebackrefs}{}')
        if len(node['backrefs']) > 1:
            refs = []
            for i in range(len(node['backrefs'])):
                refs.append(r'\Dmulti%sbacklink{%s}{%s}'
                            % (type, node['backrefs'][i], i + 1))
            self.append(r'\renewcommand{\Dmultiplebackrefs}{(%s){ }}'
                        % ', '.join(refs))
        elif len(node['backrefs']) == 1:
            self.append(r'\renewcommand{\Dsinglebackref}{%s}'
                        % node['backrefs'][0])

    def visit_footnote(self, node):
        self.process_backlinks(node, 'footnote')

    def visit_citation(self, node):
        self.process_backlinks(node, 'citation')

    def before_table(self, node):
        # A table contains exactly one tgroup.  See before_tgroup.
        pass

    def before_tgroup(self, node):
        widths = []
        total_width = 0
        for i in range(int(node['cols'])):
            assert isinstance(node[i], nodes.colspec)
            widths.append(int(node[i]['colwidth']) + 1)
            total_width += widths[-1]
        del node[:len(widths)]
        tablespec = '|'
        for w in widths:
            # 0.93 is probably wrong in many cases.  XXX Find a
            # solution which works *always*.
            tablespec += r'p{%s\textwidth}|' % (0.93 * w /
                                                max(total_width, 60))
        self.append(r'\Dmaketable{%s}{' % tablespec)
        self.context.append('}')
        raise SkipAttrParentLaTeX

    def depart_tgroup(self, node):
        self.append(self.context.pop())

    def before_row(self, node):
        raise SkipAttrParentLaTeX

    def before_thead(self, node):
        raise SkipAttrParentLaTeX

    def before_tbody(self, node):
        raise SkipAttrParentLaTeX

    def is_simply_entry(self, node):
        return (len(node) == 1 and isinstance(node[0], nodes.paragraph) or
                len(node) == 0)

    def before_entry(self, node):
        is_leftmost = 0
        if node.hasattr('morerows'):
            self.document.reporter.severe('Rowspans are not supported.')
            # Todo: Add empty cells below rowspanning cell and issue
            # warning instead of severe.
        if node.hasattr('morecols'):
            # The author got a headache trying to implement
            # multicolumn support.
            if not self.is_simply_entry(node):
                self.document.reporter.severe(
                    'Colspanning table cells may only contain one paragraph.')
                # Todo: Same as above.
            # The number of columns this entry spans (as a string).
            colspan = int(node['morecols']) + 1
            del node['morecols']
        else:
            colspan = 1
        # Macro to call.
        macro_name = r'\Dcolspan'
        if node.parent.index(node) == 0:
            # Leftmost column.
            macro_name += 'left'
            is_leftmost = 1
        if colspan > 1:
            self.append('%s{%s}{' % (macro_name, colspan))
            self.context.append('}')
        else:
            # Do not add a multicolumn with colspan 1 beacuse we need
            # at least one non-multicolumn cell per column to get the
            # desired column widths, and we can only do colspans with
            # cells consisting of only one paragraph.
            if not is_leftmost:
                self.append(r'\Dsubsequententry{')
                self.context.append('}')
            else:
                self.context.append('')
        if isinstance(node.parent.parent, nodes.thead):
            node['tableheaderentry'] = 'true'

        # Don't add \renewcommand{\Dparent}{...} because there must
        # not be any non-expandable commands in front of \multicolumn.
        raise SkipParentLaTeX

    def depart_entry(self, node):
        self.append(self.context.pop())

    def before_substitution_definition(self, node):
        raise nodes.SkipNode

    indentation_level = 0

    def node_name(self, node):
        return node.__class__.__name__.replace('_', '')

    # Attribute propagation order.
    attribute_order = ['align', 'classes', 'ids']

    def attribute_cmp(self, a1, a2):
        """
        Compare attribute names `a1` and `a2`.  Used in
        propagate_attributes to determine propagation order.

        See built-in function `cmp` for return value.
        """
        if a1 in self.attribute_order and a2 in self.attribute_order:
            return cmp(self.attribute_order.index(a1),
                       self.attribute_order.index(a2))
        if (a1 in self.attribute_order) != (a2 in self.attribute_order):
            # Attributes not in self.attribute_order come last.
            return a1 in self.attribute_order and -1 or 1
        else:
            return cmp(a1, a2)

    def propagate_attributes(self, node):
        # Propagate attributes using \Dattr macros.
        node_name = self.node_name(node)
        attlist = []
        if isinstance(node, nodes.Element):
            attlist = node.attlist()
        attlist.sort(lambda pair1, pair2: self.attribute_cmp(pair1[0],
                                                             pair2[0]))
        # `numatts` may be greater than len(attlist) due to list
        # attributes.
        numatts = 0
        pass_contents = self.pass_contents(node)
        for key, value in attlist:
            if isinstance(value, ListType):
                self.append(r'\renewcommand{\Dattrlen}{%s}' % len(value))
                for i in range(len(value)):
                    self.append(r'\Dattr{%s}{%s}{%s}{%s}{' %
                                (i+1, key, self.encode(value[i], attval=key),
                                 node_name))
                    if not pass_contents:
                        self.append('}')
                numatts += len(value)
            else:
                self.append(r'\Dattr{}{%s}{%s}{%s}{' %
                            (key, self.encode(unicode(value), attval=key),
                             node_name))
                if not pass_contents:
                    self.append('}')
                numatts += 1
        if pass_contents:
            self.context.append('}' * numatts)  # for Emacs: {
        else:
            self.context.append('')

    def visit_docinfo(self, node):
        raise NotImplementedError('Docinfo not yet implemented.')

    def visit_document(self, node):
        document = node
        # Move IDs into TextElements.  This won't work for images.
        # Need to review this.
        for node in document.traverse(nodes.Element):
            if node.has_key('ids') and not isinstance(node,
                                                      nodes.TextElement):
                next_text_element = node.next_node(nodes.TextElement)
                if next_text_element:
                    next_text_element['ids'].extend(node['ids'])
                    node['ids'] = []

    def pass_contents(self, node):
        r"""
        Return true if the node contents should be passed in
        parameters of \DN... and \Dattr.
        """
        return not isinstance(node, (nodes.document, nodes.section))

    def dispatch_visit(self, node):
        skip_attr = skip_parent = 0
        # TreePruningException to be propagated.
        tree_pruning_exception = None
        if hasattr(self, 'before_' + node.__class__.__name__):
            try:
                getattr(self, 'before_' + node.__class__.__name__)(node)
            except SkipParentLaTeX:
                skip_parent = 1
            except SkipAttrParentLaTeX:
                skip_attr = 1
                skip_parent = 1
            except nodes.SkipNode:
                raise
            except (nodes.SkipChildren, nodes.SkipSiblings), instance:
                tree_pruning_exception = instance
            except nodes.SkipDeparture:
                raise NotImplementedError(
                    'SkipDeparture not usable in LaTeX writer')

        if not isinstance(node, nodes.Text):
            node_name = self.node_name(node)
            # attribute_deleters will be appended to self.context.
            attribute_deleters = []
            if not skip_parent and not isinstance(node, nodes.document):
                self.append(r'\renewcommand{\Dparent}{%s}'
                            % self.node_name(node.parent))
                for name, value in node.attlist():
                    if not isinstance(value, ListType) and not ':' in name:
                        macro = r'\DcurrentN%sA%s' % (node_name, name)
                        self.append(r'\def%s{%s}' % (
                            macro, self.encode(unicode(value), attval=name)))
                        attribute_deleters.append(r'\let%s=\relax' % macro)
            self.context.append('\n'.join(attribute_deleters))
            if self.pass_contents(node):
                self.append(r'\DN%s{' % node_name)
                self.context.append('}')
            else:
                self.append(r'\Dvisit%s' % node_name)
                self.context.append(r'\Ddepart%s' % node_name)
            self.indentation_level += 1
            if not skip_attr:
                self.propagate_attributes(node)
            else:
                self.context.append('')

        if (isinstance(node, nodes.TextElement) and
            not isinstance(node.parent, nodes.TextElement)):
            # Reset current quote to left.
            self.left_quote = 1

        # Call visit_... method.
        try:
            nodes.SparseNodeVisitor.dispatch_visit(self, node)
        except LaTeXException:
            raise NotImplementedError(
                'visit_... methods must not raise LaTeXExceptions')

        if tree_pruning_exception:
            # Propagate TreePruningException raised in before_... method.
            raise tree_pruning_exception

    def is_invisible(self, node):
        # Return true if node is invisible or moved away in the LaTeX
        # rendering.
        return (not isinstance(node, nodes.Text) and
                (isinstance(node, nodes.Invisible) or
                 isinstance(node, nodes.footnote) or
                 isinstance(node, nodes.citation) or
                 # Assume raw nodes to be invisible.
                 isinstance(node, nodes.raw) or
                 # Floating image or figure.
                 node.get('align') in ('left', 'right')))

    def is_visible(self, node):
        return not self.is_invisible(node)

    def needs_space(self, node):
        """Two nodes for which `needs_space` is true need auxiliary space."""
        # Return true if node is a visible block-level element.
        return ((isinstance(node, nodes.Body) or
                 isinstance(node, nodes.topic)) and
                not (self.is_invisible(node) or
                     isinstance(node.parent, nodes.TextElement)))

    def always_needs_space(self, node):
        """
        Always add space around nodes for which `always_needs_space()`
        is true, regardless of whether the other node needs space as
        well.  (E.g. transition next to section.)
        """
        return isinstance(node, nodes.transition)

    def dispatch_departure(self, node):
        # Call departure method.
        nodes.SparseNodeVisitor.dispatch_departure(self, node)

        if not isinstance(node, nodes.Text):
            # Close attribute and node handler call (\DN...{...}).
            self.indentation_level -= 1
            self.append(self.context.pop() + self.context.pop())
            # Delete \Dcurrent... attribute macros.
            self.append(self.context.pop())
            # Get next sibling.
            next_node = node.next_node(
                ascend=0, siblings=1, descend=0,
                condition=self.is_visible)
            # Insert space if necessary.
            if  (self.needs_space(node) and self.needs_space(next_node) or
                 self.always_needs_space(node) or
                 self.always_needs_space(next_node)):
                if isinstance(node, nodes.paragraph) and isinstance(next_node, nodes.paragraph):
                    # Space between paragraphs.
                    self.append(r'\Dparagraphspace')
                else:
                    # One of the elements is not a paragraph.
                    self.append(r'\Dauxiliaryspace')