Sqlite and performances in LiveCode

Trevor DeVore lists at mangomultimedia.com
Tue Mar 13 13:49:41 EDT 2012

On Mon, Mar 12, 2012 at 8:17 PM, Pete <pete at mollysrevenge.com> wrote:

> Thanks for making that change.
> I've been following up a bit more on the behavior of GetDataForLine being
> called in repeated cycles for the number of lines in the datagrid.  As a
> reminder, the datagrid has 11 visible lines, GetDataForLine gets called
> once for lines 1-12, then a second time for lines 1-2 again, and
> occasionally a third time for lines 1-2.
> I think I know the reason this is happening.
> The first GetDataForLine cycle happens when I set the dgProps["Columns"]
> property of the datagrid.
> The second cycle happens when I set the dgNumberOfRecords property.
> There's a possible third cycle because sometimes I set the dgProps["Sort By
> Column"] property.
> I have tried setting the dgNumberOfRecords to empty, zero, or NULL before
> any of the above properties are changed but it doesn't seem to make any
> difference.

If you have the dgNumberOfRecords set to a positive number then that makes
sense as the data grid has to redraw.

If the dgNumberOfRecords is set to 0 (and messages aren't locked when
setting it) then I'm not sure why that is. Setting the dgNumberOfRecords to
0 should do the trick as it empties out the internal sDataArray array.
GetDataForLine is only sent if an entry in the sDataArray array is NULL.

Trevor DeVore
Blue Mango Learning Systems
www.clarify-it.com    -    www.screensteps.com

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