var gridData = $("#grid").data("kendoGrid");
var intStartRN = 0;                 // start rownumber
var intEndRN = 0;                    // end rownumber
var nextStartRN = 0;                // if ctrl-clicked, this will be the next startpoint for shift-click
var arrSelectedRows = [];             // Rows to be selected
var arrCCSelectedRows = [];            // ctrl click selected rows (global)
var arrCCUnSelectedRows = [];        // ctrl click unselected rows (global)

gridData.bind('dataBound', function()
{
    // First check what items to select from previous selections
    gridData.clearSelection(); // always clear selection

    if(elements = $("#gridOutboundOrders").find("table.k-selectable tr.k-master-row"))
    {
        if(intStartRN>0)    // User has previously clicked
        {
            arrSelectedRows = []; // empty previous selection
            $.each(elements, function(index, objTr) // walk through all selectable rows
            {
                currentUid    = $(objTr).attr("data-uid"); // determine uid of current row
                currentRn    = gridData.dataSource.getByUid(currentUid).rn; // determine current row number from datasource

                if($.inArray(currentRn, arrCCSelectedRows)>=0 || ($.inArray(currentRn, arrCCUnSelectedRows) < 0 && currentRn >= intStartRN && currentRn <= intEndRN)) // check if row should be selected
                {
                    arrSelectedRows.push(objTr); // add item to arrSelectedRows (array of rows to be selected)
                }
            });

            gridData.select(arrSelectedRows); // do actual select via grid select function
        }
    }

    // Bind onclick to all trs
    if(elements = $("#gridOutboundOrders").find("table.k-selectable tr.k-master-row"))
    {
        $.each(elements, function(index, objTr) // bind click events to all selectable rows
        {
            $(objTr).off('click'); // clear all clicks first
            $(objTr).on('click', function(e) // bind new onclick
            {
                gridData.clearSelection(); // always clear selection, as Kendo delivers random selections on shift-click, and doesn't clear selections properly, either
                arrSelectedRows        = []; // in case of a click event, clear arrSelectedRows
                var selectedUid     = $(e.currentTarget).attr("data-uid"); // uid of clicked row
                var selectedRn        = gridData.dataSource.getByUid(selectedUid).rn; // get rn from datasource by uid

                // check what to select, based by rownumber
                if(e.shiftKey) // shift-click
                {
                    // empty all selections
                    arrCCSelectedRows     = [];
                    arrCCUnSelectedRows    = [];

                    if(nextStartRN>0) // previous click was ctrl-click;
                    {
                        intStartRN = nextStartRN; //use previous click location as start-location
                        nextStartRN = 0;
                    }

                    // set endrn to current row number
                    intEndRN            = gridData.dataSource.getByUid(selectedUid).rn;

                    if(intStartRN <= intEndRN) // make sure we start the loop from small to large number
                    {
                        loopCCStart = intStartRN;
                        loopCCEnd = intEndRN;
                    }
                    else
                    {
                        loopCCStart = intEndRN;
                        loopCCEnd = intStartRN;
                    }

                    for(i=loopCCStart, j=loopCCEnd; i<=j; i++) // loop from start to end for next possible control-click
                    {
                        arrCCSelectedRows.push(i); // add rownumber to selected rows for next possible control-click
                    }
                }
                else if(e.ctrlKey) // control-click
                {
                    // in case of a previous active shift-click selection, check what items are selected
                    nextStartRN = selectedRn; // set nextStartRN on current rn (to be used by next possible shift-click)
                    if($.inArray(selectedRn, arrCCSelectedRows) < 0) // ctrl-clicked row not in arrCCSelectedRows yet (not selected yet)
                    {
                        arrCCSelectedRows.push(selectedRn); // thus add it to arrCCSelectedRows
                        if($.inArray(selectedRn, arrCCUnSelectedRows)>=0) arrCCUnSelectedRows.splice($.inArray(selectedRn, arrCCUnSelectedRows),1); // and remove it from arrCCUnSelectedRows
                    }
                    else // ctrl-clicked row already in arrCCSelectedRows (thus already selected)
                    {
                        arrCCUnSelectedRows.push(selectedRn); // hence deselect row (add it to unselected rows)
                        if($.inArray(selectedRn, arrCCSelectedRows)>=0) arrCCSelectedRows.splice($.inArray(selectedRn, arrCCSelectedRows),1); // and remove it from arrCCSelectedRows
                    }
                }
                else // normal click (or other click+key combi)
                {
                    arrCCSelectedRows     = []; // remove all ctrl-click selected rows
                    arrCCUnSelectedRows    = []; // remove all ctrl-click unselected rows
                    intStartRN    = selectedRn; // set start rownumber to currently clicked row
                    intEndRN    = selectedRn; // set end rownumber to currently clicked row
                }

                // walk through currently shown rows and create selection
                // make sure we start from small row number to large rownumber
                var myStartRN     = intStartRN;
                var myEndRN        = intEndRN;
                if(intStartRN > intEndRN)
                {
                    myStartRN = intEndRN;
                    myEndRN = intStartRN;
                }
                var currentRows = $("#gridOutboundOrders").find("table.k-selectable tr.k-master-row"); // all currently shown selectable rows
                $.each(currentRows, function(index, currentRow) // walk over all these rows
                {
                    var currentUid    = $(currentRow).attr("data-uid");                // uid of current row
                    var currentRn    = gridData.dataSource.getByUid(currentUid).rn;    // rn of current row

                    if($.inArray(currentRn, arrCCSelectedRows) >= 0 || (currentRn >= myStartRN && currentRn <= myEndRN && $.inArray(currentRn, arrCCUnSelectedRows) < 0)) // check if row should be selected
                    {
                        arrSelectedRows.push(currentRow);                            // add row to arrSelectedRows array
                    }
                });

                gridData.select(arrSelectedRows); // select rows via grid select function
            });
        });
    }
});