From 67132b1e64038f65e9b8917ea29748785819f168 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 19 Jun 2020 19:09:33 +0530
Subject: [PATCH] Get MathJax 3 working with PDF output as well

---
 resources/pdf-mathjax-loader.js     | 76 +++++++++++++++--------------
 src/calibre/gui2/viewer/web_view.py | 29 +----------
 2 files changed, 40 insertions(+), 65 deletions(-)

diff --git a/resources/pdf-mathjax-loader.js b/resources/pdf-mathjax-loader.js
index 7a47fc4b56..bb941b807c 100644
--- a/resources/pdf-mathjax-loader.js
+++ b/resources/pdf-mathjax-loader.js
@@ -8,44 +8,46 @@
 
 (function() {
 "use strict";
+    var base = document.currentScript ? document.currentScript.getAttribute('data-mathjax-path') : null;
+    var for_pdf_renderer = !!base;
 
-    function init_mathjax() {
-        var orig = window.MathJax.Ajax.fileURL.bind(window.MathJax.Ajax);
-
-        window.MathJax.Ajax.fileURL = function(mathjax_name) {
-            var ans = orig(mathjax_name);
-            if (mathjax_name.startsWith('[MathJax]/../fonts')) {
-                ans = ans.replace('/../fonts', '/fonts');
-            }
-            return ans;
-        };
+    function on_mathjax_finish() {
+        if (for_pdf_renderer) document.title = "mathjax-load-complete";
+        else document.documentElement.dispatchEvent(new CustomEvent("calibre-mathjax-typeset-done"));
     }
-
-    var base = document.currentScript.getAttribute('data-mathjax-path');
-    if (!base.endsWith('/')) base += '/';
-
-    var script = document.createElement('script');
-    script.type = 'text/javascript';
-    script.setAttribute('async', 'async');
-    script.onerror = function (ev) {
-        console.log('Failed to load MathJax script: ' + ev.target.src);
+    window.MathJax = {};
+    window.MathJax.options = {
+        renderActions: {
+            // disable the mathjax context menu
+            addMenu: [0, '', ''],
+        },
     };
-    script.src = base + 'MathJax.js';
-    window.MathJax = {AuthorInit:  init_mathjax};
-    script.text = `
-        document.title = 'mathjax-load-started';
-        MathJax.Hub.signal.Interest(function (message) {if (String(message).match(/error/i)) {console.log(message)}});
-        MathJax.Hub.Config({
-            positionToHash: false,
-            showMathMenu: false,
-            extensions: ["tex2jax.js", "asciimath2jax.js", "mml2jax.js"],
-            jax: ["input/TeX", "input/MathML", "input/AsciiMath", "output/CommonHTML"],
-            TeX: {
-                extensions: ["AMSmath.js", "AMSsymbols.js", "noErrors.js", "noUndefined.js"]
-            }
-                });
-        MathJax.Hub.Startup.onload();
-        MathJax.Hub.Register.StartupHook("End", function() { document.title = "mathjax-load-complete"; });
-    `.trim();
-    document.head.appendChild(script);
+    window.MathJax.loader = {
+        load: ['input/tex-full', 'input/asciimath', 'input/mml', 'output/chtml'],
+    };
+    window.MathJax.startup = {
+        ready: () => {
+            MathJax.startup.defaultReady();
+            MathJax.startup.promise.then(on_mathjax_finish);
+        },
+    };
+    for (const s of document.scripts) {
+        if (s.type === "text/x-mathjax-config") {
+            var es = document.createElement('script');
+            es.text = s.text;
+            document.head.appendChild(es);
+            document.head.removeChild(es);
+        }
+    }
+    if (for_pdf_renderer) {
+        if (!base.endsWith('/')) base += '/';
+        var script = document.createElement('script');
+        script.type = 'text/javascript';
+        script.setAttribute('async', 'async');
+        script.onerror = function (ev) {
+            console.log('Failed to load MathJax script: ' + ev.target.src);
+        };
+        script.src = base + 'startup.js';
+        document.head.appendChild(script);
+    }
 })();
diff --git a/src/calibre/gui2/viewer/web_view.py b/src/calibre/gui2/viewer/web_view.py
index 62e568c257..83fe3de839 100644
--- a/src/calibre/gui2/viewer/web_view.py
+++ b/src/calibre/gui2/viewer/web_view.py
@@ -178,34 +178,7 @@ class UrlSchemeHandler(QWebEngineUrlSchemeHandler):
                     prints("Failed to get mathjax file: {} with error: {}".format(name, err))
                     return self.fail_request(rq, rq.RequestFailed)
                 if name.endswith('/startup.js'):
-                    raw = b'''
-                    window.MathJax = {};
-                    window.MathJax.options = {
-                        renderActions: {
-                            // disable the mathjax context menu
-                            addMenu: [0, '', ''],
-                        },
-                    };
-                    window.MathJax.loader = {
-                        load: ['input/tex-full', 'input/asciimath', 'input/mml', 'output/chtml'],
-                    };
-                    window.MathJax.startup = {
-                        ready: () => {
-                            MathJax.startup.defaultReady();
-                            MathJax.startup.promise.then(() => {
-                                document.documentElement.dispatchEvent(new CustomEvent("calibre-mathjax-typeset-done"));
-                            });
-                        },
-                    };
-                    for (const s of document.scripts) {
-                        if (s.type === "text/x-mathjax-config") {
-                            es = document.createElement('script');
-                            es.text = s.text;
-                            document.head.appendChild(es);
-                            document.head.removeChild(es);
-                        }
-                    }
-                    ''' + raw
+                    raw = P('pdf-mathjax-loader.js', data=True, allow_user_override=False) + raw
                 send_reply(rq, mt, raw)
         elif not name:
             send_reply(rq, 'text/html', viewer_html())