Initial import

ebook_converter/ebooks/docx/toc.py

@@ -0,0 +1,143 @@
+#!/usr/bin/env python2
+# vim:fileencoding=utf-8
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+__license__ = 'GPL v3'
+__copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
+
+from collections import namedtuple
+from itertools import count
+
+from lxml.etree import tostring
+
+from calibre.ebooks.metadata.toc import TOC
+from calibre.ebooks.oeb.polish.toc import elem_to_toc_text
+from polyglot.builtins import iteritems, range
+
+
+def from_headings(body, log, namespace, num_levels=3):
+    ' Create a TOC from headings in the document '
+    tocroot = TOC()
+    all_heading_nodes = body.xpath('//*[@data-heading-level]')
+    level_prev = {i+1:None for i in range(num_levels)}
+    level_prev[0] = tocroot
+    level_item_map = {i:frozenset(
+        x for x in all_heading_nodes if int(x.get('data-heading-level')) == i)
+        for i in range(1, num_levels+1)}
+    item_level_map = {e:i for i, elems in iteritems(level_item_map) for e in elems}
+
+    idcount = count()
+
+    def ensure_id(elem):
+        ans = elem.get('id', None)
+        if not ans:
+            ans = 'toc_id_%d' % (next(idcount) + 1)
+            elem.set('id', ans)
+        return ans
+
+    for item in all_heading_nodes:
+        lvl = plvl = item_level_map.get(item, None)
+        if lvl is None:
+            continue
+        parent = None
+        while parent is None:
+            plvl -= 1
+            parent = level_prev[plvl]
+        lvl = plvl + 1
+        elem_id = ensure_id(item)
+        text = elem_to_toc_text(item)
+        toc = parent.add_item('index.html', elem_id, text)
+        level_prev[lvl] = toc
+        for i in range(lvl+1, num_levels+1):
+            level_prev[i] = None
+
+    if len(tuple(tocroot.flat())) > 1:
+        log('Generating Table of Contents from headings')
+        return tocroot
+
+
+def structure_toc(entries):
+    indent_vals = sorted({x.indent for x in entries})
+    last_found = [None for i in indent_vals]
+    newtoc = TOC()
+
+    if len(indent_vals) > 6:
+        for x in entries:
+            newtoc.add_item('index.html', x.anchor, x.text)
+        return newtoc
+
+    def find_parent(level):
+        candidates = last_found[:level]
+        for x in reversed(candidates):
+            if x is not None:
+                return x
+        return newtoc
+
+    for item in entries:
+        level = indent_vals.index(item.indent)
+        parent = find_parent(level)
+        last_found[level] = parent.add_item('index.html', item.anchor,
+                    item.text)
+        for i in range(level+1, len(last_found)):
+            last_found[i] = None
+
+    return newtoc
+
+
+def link_to_txt(a, styles, object_map):
+    if len(a) > 1:
+        for child in a:
+            run = object_map.get(child, None)
+            if run is not None:
+                rs = styles.resolve(run)
+                if rs.css.get('display', None) == 'none':
+                    a.remove(child)
+
+    return tostring(a, method='text', with_tail=False, encoding='unicode').strip()
+
+
+def from_toc(docx, link_map, styles, object_map, log, namespace):
+    XPath, get, ancestor = namespace.XPath, namespace.get, namespace.ancestor
+    toc_level = None
+    level = 0
+    TI = namedtuple('TI', 'text anchor indent')
+    toc = []
+    for tag in XPath('//*[(@w:fldCharType and name()="w:fldChar") or name()="w:hyperlink" or name()="w:instrText"]')(docx):
+        n = tag.tag.rpartition('}')[-1]
+        if n == 'fldChar':
+            t = get(tag, 'w:fldCharType')
+            if t == 'begin':
+                level += 1
+            elif t == 'end':
+                level -= 1
+                if toc_level is not None and level < toc_level:
+                    break
+        elif n == 'instrText':
+            if level > 0 and tag.text and tag.text.strip().startswith('TOC '):
+                toc_level = level
+        elif n == 'hyperlink':
+            if toc_level is not None and level >= toc_level and tag in link_map:
+                a = link_map[tag]
+                href = a.get('href', None)
+                txt = link_to_txt(a, styles, object_map)
+                p = ancestor(tag, 'w:p')
+                if txt and href and p is not None:
+                    ps = styles.resolve_paragraph(p)
+                    try:
+                        ml = int(ps.margin_left[:-2])
+                    except (TypeError, ValueError, AttributeError):
+                        ml = 0
+                    if ps.text_align in {'center', 'right'}:
+                        ml = 0
+                    toc.append(TI(txt, href[1:], ml))
+    if toc:
+        log('Found Word Table of Contents, using it to generate the Table of Contents')
+        return structure_toc(toc)
+
+
+def create_toc(docx, body, link_map, styles, object_map, log, namespace):
+    ans = from_toc(docx, link_map, styles, object_map, log, namespace) or from_headings(body, log, namespace)
+    # Remove heading level attributes
+    for h in body.xpath('//*[@data-heading-level]'):
+        del h.attrib['data-heading-level']
+    return ans