wxGrid performance

Jeff Peery wrote:
> Hello, I'm using a wxgrid in my application and it
seems to get very 
> slow in I have more than 1000 cells. most of the
problems occurs when I 
> set the background color of cells, using
SetCellBackgroundColor(). If I 
> don't set the background color the grid performs much
quicker (I can 
> scoll through the spreadsheet without have to wait for
it to refresh). 
> Is there a better way to set the background color so it
won't cause the 
> grid to be so slow?
> 
> Also to set the cell data I iterate through all the
data points and use 
> SetCellValue() to set the cell data. I also use
SetRowLabelValue() to 
> set the row label. For datasets that are large (in the
thousands) this 
> is too slow to redraw. Is there a quicker way to draw
the spreadsheet? 
> Thanks.

You can get lightning-fast grid performance if you implement
it in a 
virtual fashion. Going virtual means you never iterate your
data points. 
Instead, you configure the grid and the underlying data
table to only 
look up and return the data the grid asks for. You do this
in the 
GetValue() method of the grid's table.

See the wxPython demo - I think it is call GridMegaWidget or
something 
like that.

You can use similar techniques for the cell background
color.

If your data is coming from a database like SQLite, MySQL,
or the like, 
you may wish to take a look at Dabo: our dGrid handles all
the complex 
bits underneath, leaving a nice clean API for you to deal
with for 
displaying records and fields from a data cursor. However,
if what you 
want is a spreadsheet, that may have arbitrary cell content
not related 
to an underlying data cursor, our grid is probably not
suitable for your 
needs.

HTH

-- 
pkm ~ http://paulmcnett.com

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Jeff Peery wrote:
> Hello, I'm using a wxgrid in my application and it
seems to get very 
> slow in I have more than 1000 cells. most of the
problems occurs when I 
> set the background color of cells, using
SetCellBackgroundColor(). If I 
> don't set the background color the grid performs much
quicker (I can 
> scoll through the spreadsheet without have to wait for
it to refresh). 
> Is there a better way to set the background color so it
won't cause the 
> grid to be so slow?
> 
> Also to set the cell data I iterate through all the
data points and use 
> SetCellValue() to set the cell data. I also use
SetRowLabelValue() to 
> set the row label. For datasets that are large (in the
thousands) this 
> is too slow to redraw. Is there a quicker way to draw
the spreadsheet? 
> Thanks.

Use a table and provide the cell data and attributes from it

"on-demand".  Take a look at the "HUGE
table" sample in the demo.  It 
has 100 million cells, uses background colors, and is very
fast.


-- 
Robin Dunn
Software Craftsman
http://wxPython.org  Java
give you jitters?  Relax with wxPython!


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