[Qt-interest] Poor performance of "setBackground()" API in QTableWidgetItem class in Qt 4.5.1

[Mark Pereira]

Hi Seam,

In my application I need to set the background color of couple of cells 
in the table only, so setting the background of the complete table wont 
work.

Regards,
Mark

Sean Harmer wrote:
> Hi,
>
> On Thursday 11 Jun 2009 04:26:25 Mark Pereira wrote:
>   
>> Hi,
>>
>> I have been using Qt 4.3.3 for a while and have recently moved to
>> Qt4.5.1. I have noticed that the performance of the "setBackground()"
>> API of QTableWidgetItem class has slowed down dramatically.
>>
>> I have attached a sample piece of code which can be used to reproduce
>> this problem. In Qt 4.3.3. it takes around 407msec to complete setting
>> the background, while in Qt 4.5.1 it takes 68,567msec for the same task.
>> I ran this test on a Intel Core Duo PC (1.8 GHz) with 2 GB RAM.
>>
>> Any suggestions as to how to improve this performance.
>>     
> Why not set the background colour of the whole widget just once rather than 
> setting the background colour of each of many items
>   
> Two simple ways to do this:
>
> (i) Set the Base color in the widgets pallet and then setAutoFillBackgrround( 
> true ).
>
> or 
>
> (ii) Use a simple style sheet:
>
> QTableWidget {
> background-color: yellow;
> }
>
> Cheers,
>
> Sean
>
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>   



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