[Customdrawn] Force Screen Update When Busy Processing

[Peter]

I have raised this subject on the Android forum, but no solutions.
I am scanning through many lines of data (up tp 200000 lines) and would like to monitor how far the scan has progressed. As soon as the Scan button is pressed, the screen freezes and does not allow updates to the screen until the scan is complete.
I have tried Form and component update, refresh, invalidate and repaint, but none allow the screen to update until the scan is complete.
Is there a modification to the customdrawn widgetset or to the java activity file which will allow such updates? I notice in the activity.java that there are View Invalidate functions, but I do not know how to access them whilst a scan is in progress.

Regards
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.lazarus-ide.org/pipermail/customdrawn/attachments/20131110/5b2b3fce/attachment-0002.html>