/** Gibt ein ins Grid passende GridItem zurück, das das BitmapImage bitImg anzeigt **/
        public GridItem getGridItem(BitmapImage bitImg)
        {
            Image img = new Image();
            img.Source = bitImg;
            GridItem newItem = new GridItem();
            newItem.Content = img;

            if (img.MinHeight != 0 && img.MinWidth != 0)
            {
                newItem.Width = img.MinWidth * 2;
                newItem.Height = img.MinHeight * 2;
            }
            else
            {
                Size s = GetTileSize();
                newItem.Width = s.Width;
                newItem.Height = s.Height;
            }

            return newItem;
        }
        /** Entfernt das item mit der ID itemId vom Grid **/
        public void remove(string itemId)
        {
            GridItem itemToBeRemoved = getItemForId(itemId);

            this.Children.Remove(itemToBeRemoved);
        }
        /*  ---------------------------- 2D ---------------------------- */
        private void initGrid()
        {
            machineMap machines = ClientServerUtil.getInstance().getFactory();
            if (machines == null || machines.map == null)
            {
                return;
            }
            foreach (machineMapEntry machine in machines.map)
            {
                string instanceID = machine.key;
                int classID = getClassIdFromItemId(instanceID);
                position pos = machine.value;
                GridItem newItem = new GridItem();
                Image img = icons.getImage(classID);
                newItem.Content = img;

            #if DEBUG
                Console.WriteLine("MainWindow.initGrid: instanceID = " + instanceID);
                Console.WriteLine("MainWindow.initGrid: classID = " + classID);
            #endif

                Size s = GridC.GetTileSize();
                newItem.Width = s.Width;
                newItem.Height = s.Height;
                newItem.Angle = getAngleFromDirection(pos.direction);
                newItem.instanceId = instanceID;
                GridC.placeItem(newItem, pos.x, pos.y);
            }
        }