[PyQt] QPixmap issue with pyqt 4.5.1

Frank Schima schimaf at boulder.nist.gov
Mon Jun 29 19:49:06 BST 2009

On Jun 29, 2009, at 10:56 AM, Phil Thompson wrote:

> On Mon, 29 Jun 2009 08:48:12 -0600, Frank Schima <schimaf at boulder.nist.gov 
> >
> wrote:
>> On Jun 26, 2009, at 10:52 AM, Frank Schima wrote:
>>> I'm seeing a strange issue with either QPixmap or QImage loading
>>> from a data string. In pyqt 4.4.4, the following attached example
>>> code produces an image - it looks like noise as expected. But with
>>> pyqt 4.5.1, it appears completely blank. I expect to see the noise-
>>> like image. Am I doing something wrong, or has something changed
>>> with regards to this in 4.5?
>>> I'm running on Mac OS X 10.5.7 and python 2.5.4 using pyqt installed
>>> from Macports. Note: I modified my local portfile to install pyqt
>>> 4.5.1 because Macports is currently at version 4.4.4.
>> The problem turned out to be in my makeColorTable method.  
>> Specifically
>> the qRgb() function returns a different value for me with pyqt 4.5.1
>> and sip 4.8.1 than the value returned using 4.4.4/4.7.9. Should there
>> be any difference between versions for that function?
>> For example, for qRgb(0,0,0) I get -16777216 with 4.4.4 and  
>> 4278190080
>> with 4.5.1.
> Yes, there was a bug fix to ensure that the returned value was always
> unsigned.

Ah thanks. However, only the negative values work for me though (in  
either version of pyqt). My QImage with the positive values colortable  
comes out completely blank (or white). So I'm not sure how it is  
supposed to work?


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