calcFirstRecord method
Implementation
int calcFirstRecord(int index) {
final ds = dataSource!.dataSet!;
int result;
if (ds._activeRecord > _firstRecord + index + _bufferCount - 1) {
result = ds._activeRecord - (_firstRecord + index + _bufferCount - 1);
} else if (ds._activeRecord < _firstRecord + index) {
result = ds._activeRecord - (_firstRecord + index);
} else {
result = 0;
}
_firstRecord += index + result;
return result;
}