Re: [Plplot-devel] plplot_pyqt4 status

[Hazen B. <hba...@ma...>]

Hazen Babcock wrote:
> Alan W. Irwin wrote:
>> * I modified pyqt4_test.py a bit so that it would look for the plplot and
>>    plplot_pyqt4 extension modules in the correct place.  The result was a GUI
>>    with nothing plotted but no error messages.  I then modified pyqt4_test.py
>>    some more to put in some actual plot commands (as part of the
>>    initialization which, of course, is not right for the long term), but
>>    again I just got a blank GUI with no errors.  So there is obviously some
>>    more work to do on pyqt4_test.py and possibly plplot_pyqt4.sip to make an
>>    example that actually plots more than a blank screen. However, I will
>>    leave such further changes to you.  I believe all the build system stuff
>>    should just work now for you without issues.
>>
>>    N.B. it is important that the modules you import with
>>
>> from PyQt4 import QtCore, QtGui
>>
>>    in pyqt4_test.py link to the same Qt4 libraries as the plplot_pyqt4
>>    extension module.  For my downloaded Qt4.5.1 SDK version of Qt, I arrange
>>    that by specifying LD_LIBRARY_PATH appropriately.  This is not necessary
>>    if plplot_pyqt4.sip is built against the same system Qt4 libraries as
>>    QtCore and QtGui point to by default.
>>
>>    For both my system Qt4.4 version and the downloadable Qt4.5 version I get
>>    the above blank GUI result.
>>
>> I will be most interested to see whether you also replicate the blank GUI
>> for pyqt4_test.py regardless of what plplot commands are used, and, of
>> course, if you have any further build-system questions about the plplotqt
>> library or the plplot_pyqt4 extension module, let me know.
> 
> It now builds for me as well, thanks for all your efforts to get this to 
> work!
> 
> I confirm the blank plots. This is a little puzzling since the example 
> used to work. I'll see what I can do to resolve this.

Using printf debugging everything appears okay. The example is blank 
because the paint method of the ext_qt driver is getting called as 
expected. If you resize the window you can see the grey margins, also as 
expected. Plplot core calls to "plD_line_qt" are processed. The problem 
seems to be that in the function doPlot the plot buffer is empty. I 
assume that this driver still works fine for the non-python examples?

-Hazen