[platform-swt-dev] Large Tables

["Matthew Golby-Kirk" <Mgk@xxxxxxxxxx>]

Hi All,

I am writing a standalone SWT app on Windows, and require a table that holds a 
large number of rows (possibly as many as one million) with 10 columns.

Now using the Table / TableItem classes, the time taken to initialize the table
with all the data in one go takes too long, when the number of rows exceeds
about 15,000 on my machine (1.8Ghz P4, 1GB RAM WinXP), and when I exceed 160,000
entries it took over 2.5 hours to draw the table.

I have had two ideas as to ways to combat this, but both have problems, and I would
like opinions on how others may have solved this problem.


Idea 1: Write a viewport class that only shows the first 100 rows, then hook the vertical 
scroll bar with a listener , reset the maximum entries in the scroll bar and redraw the 
data in the table on each scroll event.

Now I have written the class ok, but cannot seem to hook all the events correctly,
as the table appears to reset the scroll bar's size and selection without sending an event,
so my viewport scrollbar's thumb seems to go from being small to large
without my being able to control it properly.

Idea 2: Subclass Table (which I know is not a good idea but I wanted to see if I could 
at least make things better) with a new LargeTable class and try to improve the speed 
at which things occur in the parent table by overriding methods.

Doing this I have improved the speed of showing 160,000 entries from 2.5 hours to 15 minutes
simply by adding a setNumberItems(int size) method that resized the items vector in one go, 
rather that incrementing the items vector by 4 each time as the standard Table code does. 
However this is still too slow really.

Has anyone got any better ideas, and which is the best way to go forward from here?

I have sample code I can post if it would help explain what I an trying to do in each idea...


Kind Regards,


MGK

-
Matthew Golby-Kirk   MQSeries Integrator Development
Hursley Park MP 211  IBM UK Internal 24-6700
Internet:: mgk@xxxxxxxxxx, Notes: Matthew Golby-Kirk/UK/IBM
Phone: +44-(0)-1962-816700 Fax: +44-(0)-1962-816898
http://muppet.hursey.ibm.com
"Skating away, on the thin ice of a new day..."