From 7342aebe664c7deed6dd844ef188adbd65f24c9d Mon Sep 17 00:00:00 2001
From: "Davide P. Cervone" <dpvc@union.edu>
Date: Wed, 9 Dec 2015 16:16:45 -0500
Subject: [PATCH 1/2] Allow page to enable/disable previews via API calls (for
 use with editor previews, for example).

---
 unpacked/extensions/fast-preview.js | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/unpacked/extensions/fast-preview.js b/unpacked/extensions/fast-preview.js
index a14a6d719..c71108205 100644
--- a/unpacked/extensions/fast-preview.js
+++ b/unpacked/extensions/fast-preview.js
@@ -33,6 +33,7 @@
 
   var FastPreview = MathJax.Extension["fast-preview"] = {
     version: "2.6.0-beta",
+    enabled: true,
 
     //
     //  Configuration for the chunking of the main output
@@ -62,7 +63,7 @@
         HUB.Config({"HTML-CSS": config.Chunks, CommonHTML: config.Chunks, SVG: config.Chunks});
       }
       HUB.Register.MessageHook("Begin Math Output",function () {
-        if (!done && SETTINGS.FastPreview && SETTINGS.renderer !== "PreviewHTML") {
+        if (!done && SETTINGS.FastPreview && this.enabled && SETTINGS.renderer !== "PreviewHTML") {
           update = HUB.processUpdateTime; delay = HUB.processUpdateDelay;
           style = HUB.config.messageStyle;
           HUB.processUpdateTime = config.updateTime;
@@ -81,13 +82,19 @@
         }
       });
     },
+    
+    //
+    //  Allow page to override user settings (for things like editor previews)
+    //
+    Disable: function () {this.enabled = false},
+    Enable: function () {this.enabled = true},
 
     //
     //  Insert a preview span, if there isn't one already,
     //  and call the PreviewHTML output jax to create the preview
     //
     Preview: function (data) {
-      if (!SETTINGS.FastPreview || SETTINGS.renderer === "PreviewHTML") return;
+      if (!SETTINGS.FastPreview || !this.enabled || SETTINGS.renderer === "PreviewHTML") return;
       var preview = data.script.MathJax.preview || data.script.previousSibling;
       if (!preview || preview.className !== MathJax.Hub.config.preRemoveClass) {
         preview = HTML.Element("span",{className:MathJax.Hub.config.preRemoveClass});

From 59736941161cc73d03c546fe54b8b96a9e2c28dd Mon Sep 17 00:00:00 2001
From: "Davide P. Cervone" <dpvc@union.edu>
Date: Wed, 9 Dec 2015 16:26:41 -0500
Subject: [PATCH 2/2] Make a flag for output jax to control fast preview (so we
 don't have to maintain a blakc-list here).

---
 unpacked/extensions/fast-preview.js       | 10 ++++++++--
 unpacked/jax/output/PreviewHTML/config.js |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/unpacked/extensions/fast-preview.js b/unpacked/extensions/fast-preview.js
index c71108205..2d64959ea 100644
--- a/unpacked/extensions/fast-preview.js
+++ b/unpacked/extensions/fast-preview.js
@@ -29,6 +29,7 @@
 (function (HUB,HTML,BROWSER) {
   
   var SETTINGS = HUB.config.menuSettings;
+  var JAX = MathJax.OutputJax;
   var msieColorBug = BROWSER.isMSIE && (document.documentMode||0) < 8;
 
   var FastPreview = MathJax.Extension["fast-preview"] = {
@@ -63,7 +64,7 @@
         HUB.Config({"HTML-CSS": config.Chunks, CommonHTML: config.Chunks, SVG: config.Chunks});
       }
       HUB.Register.MessageHook("Begin Math Output",function () {
-        if (!done && SETTINGS.FastPreview && this.enabled && SETTINGS.renderer !== "PreviewHTML") {
+        if (!done && FastPreview.Active()) {
           update = HUB.processUpdateTime; delay = HUB.processUpdateDelay;
           style = HUB.config.messageStyle;
           HUB.processUpdateTime = config.updateTime;
@@ -88,13 +89,18 @@
     //
     Disable: function () {this.enabled = false},
     Enable: function () {this.enabled = true},
+    
+    Active: function () {
+      return SETTINGS.FastPreview && this.enabled &&
+             !(JAX[SETTINGS.renderer]||{}).noFastPreview;
+    },
 
     //
     //  Insert a preview span, if there isn't one already,
     //  and call the PreviewHTML output jax to create the preview
     //
     Preview: function (data) {
-      if (!SETTINGS.FastPreview || !this.enabled || SETTINGS.renderer === "PreviewHTML") return;
+      if (!this.Active()) return;
       var preview = data.script.MathJax.preview || data.script.previousSibling;
       if (!preview || preview.className !== MathJax.Hub.config.preRemoveClass) {
         preview = HTML.Element("span",{className:MathJax.Hub.config.preRemoveClass});
diff --git a/unpacked/jax/output/PreviewHTML/config.js b/unpacked/jax/output/PreviewHTML/config.js
index 822f077fa..ddfe33bc7 100644
--- a/unpacked/jax/output/PreviewHTML/config.js
+++ b/unpacked/jax/output/PreviewHTML/config.js
@@ -30,6 +30,7 @@ MathJax.OutputJax.PreviewHTML = MathJax.OutputJax({
   version: "2.6.0-beta",
   directory: MathJax.OutputJax.directory + "/PreviewHTML",
   extensionDir: MathJax.OutputJax.extensionDir + "/PreviewHTML",
+  noFastPreview: true,  // don't do fast preview for this output jax
   
   config: {
     scale: 100, minScaleAdjust: 50, // global math scaling factor, and minimum adjusted scale factor