Topo2: position grid nodes it relation to the sprite layer size

Change-Id: I634b89dcc60c2a9aafbe0ec08d6075892d5063f6
diff --git a/web/gui/src/main/webapp/app/view/topo2/topo2SpriteLayer.js b/web/gui/src/main/webapp/app/view/topo2/topo2SpriteLayer.js
index 95a785e..411d130 100644
--- a/web/gui/src/main/webapp/app/view/topo2/topo2SpriteLayer.js
+++ b/web/gui/src/main/webapp/app/view/topo2/topo2SpriteLayer.js
@@ -44,13 +44,22 @@
                     loadLayout: function (id) {
                         this.container.selectAll("*").remove();
                         this.layout = ss.layout(id);
+
+                        this.width = this.layout.data.w;
+                        this.height = this.layout.data.h;
+
                         this.renderLayout();
                     },
                     createSpriteDefs: function () {
                        this.defs = this.svg.append('defs')
                             .attr('id', 'sprites');
                     },
-
+                    getWidth: function () {
+                        return this.width;
+                    },
+                    getHeight: function () {
+                        return this.height;
+                    },
                     renderSprite: function (spriteData) {
 
                         var id = spriteData.sprite.data.id,