Do not use the pyqtProperty technique to pass data between JS and Qt as it fails with newer versions of QtWebKit

src/calibre/ebooks/oeb/display/extract.coffee

@@ -163,8 +163,8 @@ class CalibreExtract
         cnode = inline_styles(node)
         return cnode.outerHTML
 
-    is_footnote_link: (a, prefix) ->
-        return is_footnote_link(a, a.href, py_bridge.value, prefix)
+    is_footnote_link: (a, prefix, linked_to_anchors) ->
+        return is_footnote_link(a, a.href, linked_to_anchors, prefix)
 
     show_footnote: (target, known_targets) ->
         if not target

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

@@ -13,7 +13,7 @@ from math import floor
 from collections import defaultdict
 
 from PyQt5.Qt import (
-    QObject, QPainter, Qt, QSize, QTimer, pyqtProperty, QEventLoop, QPixmap, QRect, pyqtSlot)
+    QObject, QPainter, Qt, QSize, QTimer, QEventLoop, QPixmap, QRect, pyqtSlot)
 from PyQt5.QtWebKit import QWebSettings
 from PyQt5.QtWebKitWidgets import QWebView, QWebPage
 
@@ -127,16 +127,6 @@ def draw_image_page(page_rect, painter, p, preserve_aspect_ratio=True):
 
 class PDFWriter(QObject):
 
-    def _pass_json_value_getter(self):
-        val = json.dumps(self.bridge_value)
-        return val
-
-    def _pass_json_value_setter(self, value):
-        self.bridge_value = json.loads(unicode(value))
-
-    _pass_json_value = pyqtProperty(str, fget=_pass_json_value_getter,
-            fset=_pass_json_value_setter)
-
     @pyqtSlot(result=unicode)
     def title(self):
         return self.doc_title
@@ -361,33 +351,32 @@ class PDFWriter(QObject):
         evaljs(self.paged_js)
         self.load_mathjax()
 
-        evaljs('''
-        Object.defineProperty(py_bridge, 'value', {
-               get : function() { return JSON.parse(this._pass_json_value); },
-               set : function(val) { this._pass_json_value = JSON.stringify(val); }
-        });
-
+        amap = evaljs('''
         document.body.style.backgroundColor = "white";
         paged_display.set_geometry(1, %d, %d, %d);
         paged_display.layout();
         paged_display.fit_images();
-        py_bridge.value = book_indexing.all_links_and_anchors();
+        ret = book_indexing.all_links_and_anchors();
         window.scrollTo(0, 0); // This is needed as getting anchor positions could have caused the viewport to scroll
+        ret;
         '''%(self.margin_top, 0, self.margin_bottom))
 
-        amap = self.bridge_value
         if not isinstance(amap, dict):
             amap = {'links':[], 'anchors':{}}  # Some javascript error occurred
+        for val in amap['anchors'].itervalues():
+            if isinstance(val, dict) and 'column' in val:
+                val['column'] = int(val['column'])
+        for href, val in amap['links']:
+            if isinstance(val, dict) and 'column' in val:
+                val['column'] = int(val['column'])
         sections = self.get_sections(amap['anchors'])
         tl_sections = self.get_sections(amap['anchors'], True)
         col = 0
 
         if self.header:
-            self.bridge_value = self.header
-            evaljs('paged_display.header_template = py_bridge.value')
+            evaljs('paged_display.header_template = ' + json.dumps(self.header))
         if self.footer:
-            self.bridge_value = self.footer
-            evaljs('paged_display.footer_template = py_bridge.value')
+            evaljs('paged_display.footer_template = ' + json.dumps(self.footer))
         if self.header or self.footer:
             evaljs('paged_display.create_header_footer("%s");'%self.hf_uuid)
 

src/calibre/gui2/toc/location.py

@@ -31,7 +31,6 @@ class Page(QWebPage):  # {{{
         secure_web_page(self.settings())
         self.js = None
         self.evaljs = self.mainFrame().evaluateJavaScript
-        self.bridge_value = None
         nam = self.networkAccessManager()
         nam.setNetworkAccessible(nam.NotAccessible)
         self.setLinkDelegationPolicy(self.DelegateAllLinks)

src/calibre/gui2/viewer/documentview.py

@@ -10,7 +10,7 @@ from functools import partial
 from future_builtins import map
 
 from PyQt5.Qt import (
-    QSize, QSizePolicy, QUrl, Qt, pyqtProperty, QPainter, QPalette, QBrush,
+    QSize, QSizePolicy, QUrl, Qt, QPainter, QPalette, QBrush,
     QDialog, QColor, QPoint, QImage, QRegion, QIcon, QAction, QMenu,
     pyqtSignal, QApplication, pyqtSlot, QKeySequence, QMimeData)
 from PyQt5.QtWebKitWidgets import QWebPage, QWebView
@@ -89,10 +89,6 @@ class Document(QWebPage):  # {{{
         self.setNetworkAccessManager(self.nam)
         self.setObjectName("py_bridge")
         self.in_paged_mode = False
-        # Use this to pass arbitrary JSON encodable objects between python and
-        # javascript. In python get/set the value as: self.bridge_value. In
-        # javascript, get/set the value as: py_bridge.value
-        self.bridge_value = None
         self.first_load = True
         self.jump_to_cfi_listeners = set()
 
@@ -197,12 +193,6 @@ class Document(QWebPage):  # {{{
 
     def add_window_objects(self):
         self.mainFrame().addToJavaScriptWindowObject("py_bridge", self)
-        self.javascript('''
-        Object.defineProperty(py_bridge, 'value', {
-               get : function() { return JSON.parse(this._pass_json_value); },
-               set : function(val) { this._pass_json_value = JSON.stringify(val); }
-        });
-        ''')
         self.loaded_javascript = False
 
     def load_javascript_libraries(self):
@@ -238,16 +228,6 @@ class Document(QWebPage):  # {{{
     def page_turn_requested(self, backwards):
         self.page_turn.emit(bool(backwards))
 
-    def _pass_json_value_getter(self):
-        val = json.dumps(self.bridge_value)
-        return val
-
-    def _pass_json_value_setter(self, value):
-        self.bridge_value = json.loads(unicode(value))
-
-    _pass_json_value = pyqtProperty(str, fget=_pass_json_value_getter,
-            fset=_pass_json_value_setter)
-
     def after_load(self, last_loaded_path=None):
         self.javascript('window.paged_display.read_document_margins()')
         self.set_bottom_padding(0)
@@ -267,19 +247,15 @@ class Document(QWebPage):  # {{{
         self.first_load = False
 
     def colors(self):
-        self.javascript('''
+        ans = self.javascript('''
             bs = getComputedStyle(document.body);
-            py_bridge.value = [bs.backgroundColor, bs.color]
+            [bs.backgroundColor, bs.color]
             ''')
-        ans = self.bridge_value
-        return (ans if isinstance(ans, list) else ['white', 'black'])
+        return ans if isinstance(ans, list) else ['white', 'black']
 
     def read_anchor_positions(self, use_cache=True):
-        self.bridge_value = tuple(self.index_anchors)
-        self.javascript(u'''
-            py_bridge.value = book_indexing.anchor_positions(py_bridge.value, %s);
-            '''%('true' if use_cache else 'false'))
-        self.anchor_positions = self.bridge_value
+        self.anchor_positions = self.javascript('book_indexing.anchor_positions(%s, %s);' % (
+            json.dumps(tuple(self.index_anchors)), 'true' if use_cache else 'false'))
         if not isinstance(self.anchor_positions, dict):
             # Some weird javascript error happened
             self.anchor_positions = {}
@@ -323,8 +299,8 @@ class Document(QWebPage):  # {{{
     def column_boundaries(self):
         if not self.loaded_javascript:
             return (0, 1)
-        self.javascript(u'py_bridge.value = paged_display.column_boundaries()')
-        return tuple(self.bridge_value)
+        ans = self.javascript(u'paged_display.column_boundaries()')
+        return tuple(int(x) for x in ans)
 
     def after_resize(self):
         if self.in_paged_mode:

src/calibre/gui2/viewer/footnote.py

@@ -137,8 +137,7 @@ class Footnotes(object):
                 linked_to_anchors = {}
             else:
                 linked_to_anchors = {anchor:0 for path, anchor in dest_path.verified_links if path == current_path}
-            self.view.document.bridge_value = linked_to_anchors
-            if a.evaluateJavaScript('calibre_extract.is_footnote_link(this, "%s://%s")' % (FAKE_PROTOCOL, FAKE_HOST)):
+            if a.evaluateJavaScript('calibre_extract.is_footnote_link(this, "%s://%s", %s)' % (FAKE_PROTOCOL, FAKE_HOST, json.dumps(linked_to_anchors))):
                 if dest_path not in self.known_footnote_targets:
                     self.known_footnote_targets[dest_path] = s = set()
                     for item in self.view.manager.iterator.spine: