arrow key navigation through images

allows visitors to use left-right keyboard keys to navigate to different images using post/next/(id) and post/prev/(id)

ext/arrowkey_navigation/main.php

@@ -0,0 +1,35 @@
+<?php
+/**
+ * Name: Arrow Key Navigation
+ * Author: Drudex Software <support@drudexsoftware.com>
+ * Link: http://drudexsoftware.com
+ * License: GPLv2
+ * Description: Allows viewers no navigate between images using the left & right arrow keys.
+ * Documentation:
+ *  Simply enable this extention in the extention manager to enable arrow key navigation.
+ */
+class arrowkey_navigation extends Extension {   
+    public function onDisplayingImage(DisplayingImageEvent $event) {
+        global $page;
+
+        $prev_url = "http://".$_SERVER['HTTP_HOST']."/post/prev/".$event->image->id;
+        $next_url = "http://".$_SERVER['HTTP_HOST']."/post/next/".$event->image->id;
+        
+        $page->add_html_header("<script type=\"text/javascript\">
+            document.onkeyup=checkKeycode;
+            function checkKeycode(e)
+            {
+                var keycode;
+                if(window.event) keycode=window.event.keyCode;
+                else if(e) keycode=e.which;
+
+                if (e.srcElement.tagName != \"INPUT\")
+                {
+                    if(keycode==\"37\") window.location.href='$prev_url';
+                    else if(keycode==\"39\") window.location.href='$next_url';
+                }
+            }
+            </script>");
+    }  
+}
+?>