Processing indicator for jquery datatable tools

Question

Am using Jquery Datatable tools for exporting a report grid contents.When i need to export a with large number of rows , the tools take lots of time delay.I need to put a "processing" indicator on this delay. I use following code for table tools -

 $('#mytable').dataTable({
    "scrollY": 385,
    "scrollX": true,
    "scrollCollapse": true,
    "bProcessing": true,
    "jQueryUI": true,
    "bSort": false,
    "bJQueryUI": true,
    "dom": 'T<"clear">lfrtip',
    "tableTools": {
        "sSwfPath": "http://cdn.datatables.net/tabletools/2.2.3/swf/copy_csv_xls_pdf.swf "
    }
});

Also i tried following callback method to put a customized indicator-

"fnClick": function ( nButton, oConfig, oFlash ) {
                        alert( 'Mouse click' );
}

This method works fine with a click event on the buttons.The actual problem is both export to pdf and click event will not work together!! How to do exporting to pdf with a processing indicator on untill its exported??