From 1246df80afff60fb934de9e8600f2b2eb1e10ac9 Mon Sep 17 00:00:00 2001
From: Nicolas Stepien <stepien.nicolas@gmail.com>
Date: Sun, 24 Feb 2013 18:49:35 +0100
Subject: [PATCH] Use Mutation Observers to observe captcha changes instead of
 Mutation Listeners when possible.

---
 4chan_x.user.js | 11 +++++++++--
 src/qr.coffee   | 12 +++++++++---
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/4chan_x.user.js b/4chan_x.user.js
index da2b3568f..1ff91b2ac 100644
--- a/4chan_x.user.js
+++ b/4chan_x.user.js
@@ -6276,7 +6276,7 @@
         }), this.ready.bind(this));
       },
       ready: function() {
-        var imgContainer, inputContainer;
+        var MutationObserver, imgContainer, inputContainer, observer;
         imgContainer = $.el('div', {
           className: 'captchaimg',
           title: 'Reload',
@@ -6293,9 +6293,16 @@
           img: imgContainer.firstChild,
           input: inputContainer.firstChild
         };
+        if (MutationObserver = window.MutationObserver || window.WebKitMutationObserver || window.OMutationObserver) {
+          observer = new MutationObserver(this.load.bind(this));
+          observer.observe(this.nodes.challenge, {
+            childList: true
+          });
+        } else {
+          $.on(this.nodes.challenge, 'DOMNodeInserted', this.load.bind(this));
+        }
         $.on(imgContainer, 'click', this.reload.bind(this));
         $.on(this.nodes.input, 'keydown', this.keydown.bind(this));
-        $.on(this.nodes.challenge, 'DOMNodeInserted', this.load.bind(this));
         $.sync('captchas', this.count.bind(this));
         this.count($.get('captchas', []));
         this.reload();
diff --git a/src/qr.coffee b/src/qr.coffee
index 505899b76..b0b312a66 100644
--- a/src/qr.coffee
+++ b/src/qr.coffee
@@ -522,9 +522,15 @@ QR =
         img:            imgContainer.firstChild
         input:          inputContainer.firstChild
 
-      $.on imgContainer,     'click',           @reload.bind @
-      $.on @nodes.input,     'keydown',         @keydown.bind @
-      $.on @nodes.challenge, 'DOMNodeInserted', @load.bind @
+      if MutationObserver = window.MutationObserver or window.WebKitMutationObserver or window.OMutationObserver
+        observer = new MutationObserver @load.bind @
+        observer.observe @nodes.challenge,
+          childList: true
+      else
+        $.on @nodes.challenge, 'DOMNodeInserted', @load.bind @
+
+      $.on imgContainer, 'click',   @reload.bind @
+      $.on @nodes.input, 'keydown', @keydown.bind @
       $.sync 'captchas', @count.bind @
       @count $.get 'captchas', []
       # start with an uncached captcha