private void addButton_Click(object sender, System.EventArgs e)
        {
            Map.Object o = new Map.Object();
            o.Extent = 0;
            ObjectPropertiesDialog propDlg = new ObjectPropertiesDialog();

            propDlg.Object = o;
            propDlg.ShowDialog();
            obj.InventoryList.Add(propDlg.Object);
            UpdateList();
        }
 private void objectsList_DoubleClick(object sender, System.EventArgs e)
 {
     if (objectsList.SelectedItem != null)
     {
         int ndx = obj.InventoryList.IndexOf((Map.Object)objectsList.SelectedItem);
         ObjectPropertiesDialog propDlg = new ObjectPropertiesDialog();
         propDlg.Object = obj.InventoryList[ndx];
         propDlg.ShowDialog();
         // Update reference because object has been cloned
         obj.InventoryList[ndx] = propDlg.Object;
         UpdateList();
     }
 }