Update wxpython.py example for wxPython 4.0 (wxPhoenix)

[cztomczak]

Patch sent by Andrew Leech in this topic:
https://groups.google.com/d/topic/cefpython/2gvlnukJpJ0/discussion

I can't test it right now, because wxPython 4.0 installation fails, but the changes do work fine with old wxPython 2.8, so it can be commited safely.

[cztomczak]

Still TODO: Test it and add top comments on which configurations were tested.

[andrewleech]

For reference, my tested configuration is:
Windows 10 x64

Main packages installed with pip:
pip install -U --pre wxPython cefpython3

wxPython-4.0.0a1-cp35-cp35m-win32.whl
cefpython3-56.1-py2.py3-none-win32.whl

[wxpython.py] CEF Python 56.1
[wxpython.py] Python 3.5.2 32bit
[wxpython.py] wxPython 4.0.0a1 msw (phoenix)

[cztomczak]

Additional fixes for wxPython 4.0 / 3.0 on Linux were applied in Issue #349. So it works fine now on Windows and Linux.

@andrewleech On the Forum you've said that you have some issues on Mac. I wonder if these issues are similar to Linux issues with handle and maybe a similar fix will work. It seems to me this might be the issue on Mac as well after finding this Phoenix issue: wxWidgets/Phoenix#37

NOTE on installing wxPython 4.0 on Linux:

I've tried installing wheel package for Python 3.5 on Linux, but it failed with error that it couldn't load "libpython3.5m.so" (there is no such file in pyenv installation of Python, only .a file I see). I ended up installing wheel package for system Python 3.4.

The error:

Traceback (most recent call last):
  File "wxpython.py", line 11, in <module>
    import wx
  File "/home/cz/.pyenv/versions/3.5.3/lib/python3.5/site-packages/wx/__init__.py", line 17, in <module>
    from wx.core import *
  File "/home/cz/.pyenv/versions/3.5.3/lib/python3.5/site-packages/wx/core.py", line 12, in <module>
    from ._core import *
ImportError: libpython3.5m.so.1.0: cannot open shared object file: No such file or directory

[andrewleech]

I've done some further testing on mac and those issues don't seem to matter.
I've found some workarounds to my issues, detailed here: https://groups.google.com/forum/#!topic/cefpython/tM8SXp_a_u0

[cztomczak]

Issue #350 fixed problems on Mac. So now it runs fine on all platforms. Closing.

[cztomczak]

Note on installing/running wxPython 4.0 on Mac:

I was able to run it with homebrew Python. When running with pyenv installation of Python I had this error:

[wxpython.py] CEF Python 56.1
[wxpython.py] Python 3.6.0 64bit
[wxpython.py] wxPython 4.0.0a1 osx-cocoa (phoenix)
This program needs access to the screen. Please run with a
Framework build of python, and only when you are logged in
on the main display of your Mac.

[andrewleech]

Ah yes, I had this same issue with virtualenv
Basically virtualenv/pyvenv appears to be reall broken on macs with regard to apps that open a gui

Apparently it's a really common issue with gui python apps on osx which I couldn't find a clear consensus on how to resolve.
https://wiki.wxpython.org/wxPythonVirtualenvOnMac

Basically it wont run with the python wrapper execrable that's created by pyvenv in .venv/bin/python
It needs the real python exe

The simplest option I've found is to copy the real python exe into the virtualenv and set PYTHONHOME so it looks in the virtualenv folder for libs etc:

cp  /usr/local/bin/python3 .venv/bin/python
PYTHONHOME=$VIRTUAL_ENV python wxpython.py

Not sure if this breaks pip etc though, it may still reference system stuff for some things.

[cztomczak]

I have resolved issues with pyenv by building Pythons with --enable-shared option on Linux and --enable-framework option on Mac set via PYTHON_CONFIGURE_OPTS env variable. See here for explanation: wxWidgets/Phoenix#288 (comment)