--- a/client/digitallibrary/jquery/jquery-test-full.html	Sun Feb 06 22:17:41 2011 +0100
+++ b/client/digitallibrary/jquery/jquery-test-full.html	Tue Feb 08 23:57:39 2011 +0100
@@ -36,7 +36,17 @@
                     interactionMode : 'fullscreen',
                     scalerBaseUrl : 'http://digilib.biblhertz.it/digilib04/servlet/Scaler'
                     };
-                 $('div.digilib').digilib(opts);
+                var $div = $('div.digilib');
+                $div.digilib(opts);
+                var obj = {
+                    'initExtension' : function() {
+                        var settings = $(this).data('digilib').settings;
+                        console.debug('initExtension:', this, 'settings:', settings);
+                        },
+                    'options' : { 'test' : 'content of option "test"' },
+                    };
+                $div.digilib('extendPlugin', obj);
+                $div.digilib('initExtension');
             });
 
         </script>

--- a/client/digitallibrary/jquery/jquery.digilib.js	Sun Feb 06 22:17:41 2011 +0100
+++ b/client/digitallibrary/jquery/jquery.digilib.js	Tue Feb 08 23:57:39 2011 +0100
@@ -585,11 +585,12 @@
                 redisplay(data);
             }
         },
-        
+
         // calibrate (only faking)
         calibrate : function (data) {
             getImageInfo(data);
-        }
+        },
+
     };
 
     // returns parameters from page url
@@ -1121,13 +1122,13 @@
         return function () {
             var $img = $(this);
             var $scaler = data.$scaler;
-            // create Transform from current area and picsize
+            // create Transform from current zoomArea and image size
             data.imgTrafo = getImgTrafo($img, data.zoomArea,
                     data.settings.rot, data.scalerFlags.hmir, data.scalerFlags.vmir);
-            console.debug("imgTrafo=", data.imgTrafo);
+            // console.debug("imgTrafo=", data.imgTrafo);
+            var imgRect = geom.rectangle($img);
+            // console.debug("imgrect=", imgRect);
             // adjust scaler div size
-            var imgRect = geom.rectangle($img);
-            console.debug("imgrect=", imgRect);
             imgRect.adjustDiv($scaler);
             // show image in case it was hidden (for example in zoomDrag)
             $img.css('visibility', 'visible');
@@ -1580,8 +1581,28 @@
         }
 
     // hook plugin into jquery
-    $.fn.digilib = function(action) {
-        if (actions[action]) {
+    $.fn.digilib = function(action, obj) {
+        // plugin extension mechanism
+        if (action === 'extendPlugin') {
+            // for each digilib $elem extend data.settings with obj.options
+            if (obj.options) {
+                this.each(function() {
+                    var $elem = $(this);
+                    // console.debug('extending:', $elem);
+                    var data = $elem.data('digilib');
+                    if (!data) {
+                        return console.log('cannot extend digilib plugin, element not initialised!');
+                        }
+                    var settings = data.settings;
+                    $.extend(settings, obj.options);
+                    // console.log('settings:', settings);
+                    });
+                }
+            delete(obj.options);
+            // extend the plugin actions (to make this useful, 
+            // maybe we need to expose some more internal functions)
+            $.extend(actions, obj);
+        } else if (actions[action]) {
             // call action on this with the remaining arguments (inserting data as first argument)
             var $elem = $(this);
             var data = $elem.data('digilib');