add 'offset' member to OpenLayers.Icon - and then use it in OpenLayers.Marker

git-svn-id: http://svn.openlayers.org/trunk/openlayers@127 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Icon.js

@@ -6,10 +6,21 @@ OpenLayers.Icon.prototype = {
     
     // {OpenLayers.Size}: size of image
     size:null,
+
+    /** distance in pixels to offset the image when being rendered
+    * @type OpenLayers.Pixel */
+    offset: null,    
     
-    initialize: function(url, size) {
+    initialize: function(url, size, offset) {
         this.size = size;
         this.url = url;
+
+        this.offset = offset;
+        if (offset == null) {
+            // default offset
+            this.offset = new OpenLayers.Pixel(size.w / 2, size.h);
+        }
+            
     },
 
     // Create a copy of this icon.

lib/OpenLayers/Marker.js

@@ -38,9 +38,7 @@ OpenLayers.Marker.prototype = {
     generateMarker: function(pixel) {
         // Create a div here, and set the location to the pixel above modified
         // by the icon size.
-        var markerOffset = new OpenLayers.Pixel(this.icon.size.w / 2, 
-                                                this.icon.size.h);
-        var iconPosition = pixel.diff(markerOffset);
+        var iconPosition = pixel.diff(this.icon.offset);
         var markerObject = OpenLayers.Util.createImage(this.icon.url,
                                                        this.icon.size,
                                                        iconPosition);