Add support for page number mapping

src/calibre/ebooks/pdf/html_writer.py

@@ -33,7 +33,7 @@ from calibre.gui2.webengine import secure_webengine
 from calibre.utils.logging import default_log
 from calibre.utils.podofo import get_podofo, set_metadata_implementation
 from calibre.utils.short_uuid import uuid4
-from polyglot.builtins import iteritems, range
+from polyglot.builtins import iteritems, range, unicode_type
 from polyglot.urllib import urlparse
 
 OK, KILL_SIGNAL = range(0, 2)
@@ -175,6 +175,19 @@ class RenderManager(QObject):
             raise SystemExit('Unknown error occurred')
         return self.results
 
+    def evaljs(self, js):
+        if not self.workers:
+            self.create_worker()
+        w = self.workers[0]
+        self.evaljs_result = None
+        w.runJavaScript(js, self.evaljs_callback)
+        QApplication.exec_()
+        return self.evaljs_result
+
+    def evaljs_callback(self, result):
+        self.evaljs_result = result
+        QApplication.instance().exit(0)
+
     def assign_work(self):
         free_workers = [w for w in self.workers if not w.working]
         while free_workers and self.pending:
@@ -423,7 +436,30 @@ def add_toc(pdf_parent, toc_parent):
             add_toc(pdf_child, child)
 
 
-def add_pagenum_toc(root, toc, opts):
+def get_page_number_display_map(render_manager, opts, num_pages, log):
+    num_pages *= 2
+    default_map = {n:n for n in range(1, num_pages + 1)}
+    if opts.pdf_page_number_map:
+        js = '''
+        function map_num(n) { return eval(MAP_EXPRESSION); }
+        var ans = {};
+        for (var i=1; i <= NUM_PAGES; i++) ans[i] = map_num(i);
+        JSON.stringify(ans);
+        '''.replace('MAP_EXPRESSION', json.dumps(opts.pdf_page_number_map), 1).replace(
+                'NUM_PAGES', unicode_type(num_pages), 1)
+        result = render_manager.evaljs(js)
+        try:
+            result = json.loads(result)
+            if not isinstance(result, dict):
+                raise ValueError('Not a dict')
+        except Exception:
+            log.warn('Could not do page number mapping, got unexpected result: {}'.format(repr(result)))
+        else:
+            default_map = {int(k): int(v) for k, v in iteritems(result)}
+    return default_map
+
+
+def add_pagenum_toc(root, toc, opts, page_number_display_map):
     body = root[-1]
     indents = []
     for i in range(1, 7):
@@ -464,7 +500,9 @@ def add_pagenum_toc(root, toc, opts):
     for level, node in toc.iterdescendants(level=0):
         tr = E('tr', cls='level-%d' % level, parent=table)
         E('td', text=node.title or _('Unknown'), parent=tr)
-        E('td', text='{}'.format(node.pdf_loc.pagenum), parent=tr)
+        num = node.pdf_loc.pagenum
+        num = page_number_display_map.get(num, num)
+        E('td', text='{}'.format(num), parent=tr)
 
 # }}}
 
@@ -504,12 +542,14 @@ def convert(opf_path, opts, metadata=None, output_path=None, log=default_log, co
         else:
             pdf_doc.append(doc)
 
+    page_number_display_map = get_page_number_display_map(manager, opts, num_pages, log)
+
     if has_toc:
         annotate_toc(toc, anchor_locations, name_anchor_map, log)
         if opts.pdf_add_toc:
             tocname = create_skeleton(container)
             root = container.parsed(tocname)
-            add_pagenum_toc(root, toc, opts)
+            add_pagenum_toc(root, toc, opts, page_number_display_map)
             container.commit()
             jobs = [job_for_name(container, tocname, None, page_layout)]
             results = manager.convert_html_files(jobs, settle_time=1)
@@ -526,6 +566,7 @@ def convert(opf_path, opts, metadata=None, output_path=None, log=default_log, co
     # TODO: Remove unused fonts
     # TODO: Remove duplicate fonts
     # TODO: Subset and embed fonts before rendering PDF
+    # TODO: Support for mathematics
 
     if cover_data:
         add_cover(pdf_doc, cover_data, page_layout, opts)

src/calibre/ebooks/pdf/render/toc.py

@@ -1,86 +0,0 @@
-#!/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>'
-
-import os
-
-from lxml.html import tostring
-from lxml.html.builder import (HTML, HEAD, BODY, TABLE, TR, TD, H2, STYLE)
-
-from polyglot.builtins import range, unicode_type
-
-
-def calculate_page_number(num, map_expression, evaljs):
-    if map_expression:
-        num = int(evaljs('(function(){{var n={}; return {};}})()'.format(
-            num, map_expression)))
-    return num
-
-
-def convert_node(toc, table, level, pdf, pdf_page_number_map, evaljs):
-    tr = TR(
-        TD(toc.text or _('Unknown')), TD(),
-    )
-    tr.set('class', 'level-%d' % level)
-    anchors = pdf.links.anchors
-
-    path = toc.abspath or None
-    frag = toc.fragment or None
-    if path is None:
-        return
-    path = os.path.normcase(os.path.abspath(path))
-    if path not in anchors:
-        return None
-    a = anchors[path]
-    dest = a.get(frag, a[None])
-    num = calculate_page_number(pdf.page_tree.obj.get_num(dest[0]), pdf_page_number_map, evaljs)
-    tr[1].text = unicode_type(num)
-    table.append(tr)
-
-
-def process_children(toc, table, level, pdf, pdf_page_number_map, evaljs):
-    for child in toc:
-        convert_node(child, table, level, pdf, pdf_page_number_map, evaljs)
-        process_children(child, table, level+1, pdf, pdf_page_number_map, evaljs)
-
-
-def toc_as_html(toc, pdf, opts, evaljs):
-    pdf = pdf.engine.pdf
-    indents = []
-    for i in range(1, 7):
-        indents.extend((i, 1.4*i))
-    html = HTML(
-        HEAD(
-            STYLE(
-            '''
-            .calibre-pdf-toc table { width: 100%% }
-
-            .calibre-pdf-toc table tr td:last-of-type { text-align: right }
-
-            .calibre-pdf-toc .level-0 {
-                font-size: larger;
-            }
-
-            .calibre-pdf-toc .level-%d td:first-of-type { padding-left: %.1gem }
-            .calibre-pdf-toc .level-%d td:first-of-type { padding-left: %.1gem }
-            .calibre-pdf-toc .level-%d td:first-of-type { padding-left: %.1gem }
-            .calibre-pdf-toc .level-%d td:first-of-type { padding-left: %.1gem }
-            .calibre-pdf-toc .level-%d td:first-of-type { padding-left: %.1gem }
-            .calibre-pdf-toc .level-%d td:first-of-type { padding-left: %.1gem }
-            ''' % tuple(indents) + (opts.extra_css or '')
-            )
-        ),
-        BODY(
-            H2(opts.toc_title or _('Table of Contents')),
-            TABLE(),
-        )
-    )
-    body = html[1]
-    body.set('class', 'calibre-pdf-toc')
-
-    process_children(toc, body[1], 0, pdf, opts.pdf_page_number_map, evaljs)
-
-    return tostring(html, pretty_print=True, include_meta_content_type=True, encoding='utf-8')