Developing Mobile…Force.com and Sencha-Part 3, Step 2: Lookback at Query() on Apex controller

PocketCRMController.Query()

@RemoteAction
public static Response Query(QueryRequest qr) {
    Response resp = new Response();
    List < Lead > LeadList;
    filterString = qr.searchFilter;

    try {
        //Fetch all Leads for the user
        LeadList = getAllLeads();
    } catch (Exception e) {
        resp.success = false;
        resp.errorMessage = 'Query failed: ' + e.getMessage();
        return resp;
    }

    //Supply only the requested records
    for (Integer recno = qr.start; recno < (qr.start + qr.recordCount) && recno < LeadList.size(); ++recno) {
        resp.records.add(LeadList[recno]);
    }

    resp.total = LeadList.size();
    resp.success = true;
    return resp;
}