ManualTotalSummaryEngineFactory enlightenment

Can you shed some light your ManualTotalSummaryEngineFactory

My ggc is set up as fllw: I have two summary rows( one for the dollars and another for the qty). The w1, w2, and rate columns are the only editable columns. The total column is a expression/computed column.

I am interested updating the summary by just applying the delta between the old value and the new value like in the example.

Can you shed some light on how I can go about this instead of relying on the engine doing this.

I am afraid that with a couple of hundreds rows and a column length of w's which could be up to 52, I might run into some perfs issues relying on the engine to auto-calc + QueryCellStyleInfo.



dollar summary------------ $335----$235--- $100
qty summary--------------- 21------ 15 --- 6
header----descr---rate---- total--- w1 --- w2
record1---item1---10.00--- 50.00--- 4 --- 1
record2---item2---15.00---105.00--- 5 --- 2
record3---item3---20.00---180.00--- 6 --- 3