/**
 * Enables filtration delay for keeping the browser more responsive while 
 * searching for a longer keyword.
 *  @name fnSetFilteringDelay
 *  @author <a href="http://www.zygimantas.com/">Zygimantas Berziunas</a>, <a href="http://www.sprymedia.co.uk/">Allan Jardine</a> and <i>vex</i>
 *
 *  @example
 *    $(document).ready(function() {
 *        $('.dataTable').dataTable().fnSetFilteringDelay();
 *    } );
 */

jQuery.fn.dataTableExt.oApi.fnSetFilteringDelay = function ( oSettings, iDelay ) {
    var
        _that = this,
        iDelay = (typeof iDelay == 'undefined') ? 250 : iDelay;
     
    this.each( function ( i ) {
        $.fn.dataTableExt.iApiIndex = i;
        var
            $this = this, 
            oTimerId = null, 
            sPreviousSearch = null,
            anControl = $( 'input', _that.fnSettings().aanFeatures.f );
         
            anControl.unbind( 'keyup' ).bind( 'keyup', function() {
            var $$this = $this;
 
            if (sPreviousSearch === null || sPreviousSearch != anControl.val()) {
                window.clearTimeout(oTimerId);
                sPreviousSearch = anControl.val();  
                oTimerId = window.setTimeout(function() {
                    $.fn.dataTableExt.iApiIndex = i;
                    _that.fnFilter( anControl.val() );
                }, iDelay);
            }
        });
         
        return this;
    } );
    return this;
};