PySide compared to PyQt4 : problem with QImage __init__()

[lbordier]

Hello,

I'm trying to create a pyside backend for matplotlib by modifying the qt4agg backend.
Now i'm stuck with a QImage problem :

In PyQt4 the syntax is :

img = QtGui.QImage(stringBuffer, 640,480,QtGui.QImage.Format_ARGB32)

But converting to PySide raise an error because no init method accept these inputs (because of stringBuffer data).
I tried with the staticmethod QImage.fromData(stringBuffer) but it does not work.

I don't understand why pyside does not have the QImage ( uchar * data, int width, int height, Format format ) constructor ??

Could someone help me on this topic ?
How can i have the same result with a pyside syntax ?

Thanks.

[mairas]

Hi,

This is a bug in PySide - see:

http://bugs.openbossa.org/show_bug.cgi?id=489

Add yourself as a CC to the bug to get automatic updates about its progress.

Due to the bug backlog we have, it might take a month or so before we have time to fix that, though. :-(

Anyway, it's utterly cool that you're working on a matplotlib backend! I've really used matplotlib a lot for different kinds of projects of my own, and have always found the visual quality quite unmatched!

ma.

[lbordier]

OK, thanks for the reply.
Is there any way to get it working with methods like fromData or loadFromData ?

[mairas]

I haven't tested it myself, but according to the documentation, loadFromData should do exactly what you want. If it doesn't, it's a bug that should really be reported.

[lbordier]

I think i don't use it properly because with PyQt and the following code :

from PyQt4 import QtGui

fid = open('/tmp/buffer.out','r')
stringBuffer = fid.read()
fid.close()

img1 = QtGui.QImage(640,440, QtGui.QImage.Format_ARGB32)
img1.loadFromData(stringBuffer)

img1.save('test_pyqt4_1.png',format='png')

--> this make an empty png file*

img2 = QtGui.QImage(stringBuffer,640,440, QtGui.QImage.Format_ARGB32)

img2.save('test_pyqt4_2.png',format='png')

--> this make a good png file with my figure

Any idea how to use loadFromData in the good way so that i can reproduce with pyside??