From 59c5baeb1ba72cfb0cfcd9139510feb264140f6b Mon Sep 17 00:00:00 2001
From: Usman Khalid <usman.khalid@arbisoft.com>
Date: Thu, 19 Sep 2013 20:50:05 +0500
Subject: [PATCH] Disables the previous/next arrows on pdf books on the
 first/last pages respectively

---
 common/static/js/pdfviewer.js         | 6 ++++++
 lms/static/sass/course/_textbook.scss | 8 ++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/common/static/js/pdfviewer.js b/common/static/js/pdfviewer.js
index 258541e0ad..889c1e7d71 100644
--- a/common/static/js/pdfviewer.js
+++ b/common/static/js/pdfviewer.js
@@ -200,6 +200,12 @@ PDFJS.disableWorker = true;
             document.getElementById('numPages').textContent = 'of ' + pdfDocument.numPages;
             $("#pageNumber").max = pdfDocument.numPages;
             $("#pageNumber").val(pageNum);
+
+            // Enable/disable the previous/next buttons
+            if (pageNum > 1) $("#previous").addClass("enabled");
+            else $("#previous").removeClass("enabled");
+            if (pageNum < pdfDocument.numPages) $("#next").addClass("enabled");
+            else $("#next").removeClass("enabled");
         }
 
         // Go to previous page
diff --git a/lms/static/sass/course/_textbook.scss b/lms/static/sass/course/_textbook.scss
index 72d73bdb78..f839c0dd10 100644
--- a/lms/static/sass/course/_textbook.scss
+++ b/lms/static/sass/course/_textbook.scss
@@ -160,11 +160,11 @@ div.book-wrapper {
             @include transition(none);
             vertical-align: middle;
             width: 100%;
+          }
 
-            &:hover {
-              opacity: 1.0;
-              filter: alpha(opacity=100);
-            }
+          a.enabled:hover {
+            opacity: 1.0;
+            filter: alpha(opacity=100);
           }
 
           &.last {