protected override void AddHandler(object sender, EventArgs e)
        {
            var record = new TSValue();

            using (var dlg = new TSValueEditDlg()) {
                dlg.SetContext(fModel, record);

                if (dlg.ShowModal())
                {
                    fModel.TSDB.InsertValue(fPointId, record.Timestamp, record.Value);
                    UpdateContent();
                }
            }
        }
        protected override void EditHandler(object sender, EventArgs e)
        {
            var record = ListView.GetSelectedTag <TSValue>();

            if (record == null)
            {
                return;
            }

            using (var dlg = new TSValueEditDlg()) {
                dlg.SetContext(fModel, record);

                if (dlg.ShowModal())
                {
                    fModel.TSDB.UpdateValue(fPointId, record.Timestamp, record.Value);
                    UpdateContent();
                }
            }
        }