[PyQt] Design plugins in Windows

[Phil Thompson]

On 29 Mar 2016, at 12:05 am, Kyle Altendorf <sda at fstab.net> wrote:
> 
> On 2016-03-28 18:49, Kyle Altendorf wrote:
>> On 2016-03-28 18:12, Phil Thompson wrote:
>>> On 28 Mar 2016, at 10:47 pm, Kyle Altendorf <sda at fstab.net> wrote:
>>>> While my Designer widgets work quite nicely in Linux (thank you) I am unable to get them working in Windows.  I have tried many permutations of / and \ and quotes or not in PYQTDESIGNERPATH.  I also located my files in one of the default path locations (C:\Users\IEUser\.designer\plugins\python).  In no case do they show up within Designer (pyqt5.dll is listed as a plugin).  Any recommendations on how to debug/resolve this before I attempt to rebuild pyqt5.dll with debug statements written to a file?  My widgets/plugins are available on GitHub [1].
>>>> Thank you for any suggestions you care to share.
>>>> Cheers,
>>>> -kyle
>>>> [1] https://github.com/altendky/st/tree/fda167f20081ba0f24293d71535b68b2e6954bb0/epyq/widgets
>>> Does the standard example work for you?
>>> Phil
>> No, it does not seem to work either via the examples app or from the
>> command line.  In fact, unless I set PYTHONPATH to something else,
>> Designer won't even open (so example app doesn't open Designer at
>> all).  I looked for the widgets in the list and also for entries under
>> the listing of pyqt5.dll in the dialog under help and neither
>>  C:\Users\IEUser>set
>> PYQTDESIGNERPATH=c:\python34\lib\site-packages\PyQt5\examples\designer\plugins\python
>>  C:\Users\IEUser>set
>> PYTHONPATH=c:\python34\lib\site-packages\PyQt5\examples\designer\plugins\widgets
>>  C:\Users\IEUser>designer
>> <no output nor designer window>
>>  C:\Users\IEUser>set
>> PYTHONPATH=c:\python34\lib\site-packages\PyQt5\examples\designer\plugins\widget
>>  C:\Users\IEUser>designer
>>  C:\Users\IEUser>
>> <no output but designer window comes up>
>> I'm bringing up a fresh virtual machine (modern.ie Vagrant/Win10/Edge
>> x64) and will install Python 3.4.4 and PyQt 5.5.1 (both x32).  I will
>> let you know the results there.
> 
> The fresh virtual failed in the same way.  Any other particular combination you think it would be helpful to try?

A side effect of the recent changes related to uncaught Python exceptions means that, if your plugin or widget implementation has bugs it will bring down Designer. There is such a bug in one of the PyQt examples (fixed in the current snapshot) which means the whole Designer plugins example will probably fail.

You could try the latest version of the example, or remove the bad part of the version you have (it's the widget that uses OpenGL I think).

I will look at ways of making the whole thing more resilient to failures.

Phil