[Edu-sig] PySqueak: pyGTK & Cairo & pygtkglext (OpenGL) next?
Paul D. Fernhout
pdfernhout at kurtz-fernhout.com
Sat Jun 3 01:00:14 CEST 2006
Would people here be willing to install PyGTK 2.x and pygtkglext (OpenGL
on GTK) and related files on their machines *if* there was a Python-based
software package they *really* wanted to use? Mac and Windows are of
issue mainly, since GNU/Linux probably is probably trivial install. Does
anyone under Mac or Windows have happy experience doing that for either
PyGTK or the 3D extension pygtkglext (either in a home or a lab setting
While exploring the issue of restricted evaluation environments (I am
considering having PataPata windows communicate by passing textual Python
programs :-) I came across this on Python 3.0 wish list:
"Include wxPython or PyGtk in core library [for Py3K]? Would anygui also
be a good option. Place Tkinter into legacy status? (Musing again. Seems
like we need a more mainstream, higher performance standard GUI in the
core distribution. wxPython is very popular, so I suggested it as an
option. The PyGtk is an awesomely thin layer over the C library and it
makes Gtk objects look like native Python classes.)"
Now given the wx bashing lately (including from the OSI Chandler project I
linked to), and the Cairo blessing(?), that PyGTK comment got me thinking.
Also, Francois mentions somewhere he wanted to move beyond TK for his work.
Well, I just implemented a rudimentary TK proof-of-concept version of
PataPata. And the inspector is live in the world. And I am not as
dissatisfied with the look or performance of TK as I thought I would.
[Though of course it still needs more work.(*)] BUT, I read that, and the
squeaky gears in my brain start creaking, thinking, "hmmm, Python2.x, GTK,
And after a Google, this link has me pretty excited:
Writing a Widget Using Cairo and PyGTK 2.8
and so I tried the file there and it ran on my Debian machine without
needing to install anything (though I have in the past installed lots of
stuff, so I don't know about stock distributions of Debian Python, but
clearly this support is just an apt-get away apparently, at least as far
From the link:
"Cairo is a powerful 2-dimensional graphics library designed to support a
number of modern graphics techniques including stroking, alpha blending
and antialiasing. It supports multiple output formats, which allows
developers to use the same code to display graphics on the screen, print
them to the printer or accelerate them with OpenGL. As of GTK+ 2.8, GTK+
has been integrated with the Cairo 1.0 rendering library, giving
developers access to this flexible graphics API. PyGTK added Cairo support
in the 2.8 version. See the wiki for further info."
There is also PyGtkGLExt for Python 3D OpenGL support (though I have not
Example Python 3D program:
I really like the idea of using something like Cairo if it is picking up
steam (see my previous post in "Elementary Graphics Library"). And 3D
support sounds good too (rather than the TK developers leaving behind TK's
togl :-( ). As I reflect on it, I am also willing to trade-off 90% of
popularity for PataPata right now in terms of easy install for Mac/Windows
*if* it would make my life under Debian easier to get something neat
working that I and a few others want to use, and has the promise of
picking up easy install in a couple of years (like if Python3K went with
pyGTK as a default). Plus I already have wx and tk versions, so it's not
like people could not try the basic idea on those platforms.
The issue is more a matter of where I shoudl be putting more energy, since
if I could use GTK and Cairo and PyGtkGLExt for cross-platform widgets, 2D
graphics, and 3D graphics, then long-term it makes it easier for me to
maintain a system using common cross-platform standards, especially
because I don't have to put in much of an extra dumbed down
"compatibility" layer. For example, I can just pass GTK events around
rather than translate them to my own; I can use Cairo calls rather than my
own simplified 2D context; I can assume everyone is using the same way to
access 3D graphics rather than try to abstract initialization out; and so
on. Now, this compatibility issue is a bit more complex, because I would
like to run PataPata things as applets on Jython, but I'm not sure that is
important enough at the start to prevent using an otherwise promising
cross-platform solution CPython works with, given that I'm not sure how
important Applets really are, and in the future there might be more
person-power to make some GUI object wrappers that runs both on GTK and Swing.
Obviously, I could search the PyGTK and gtkglext list archives:
but I was curious what people here had to say from an educator context.
There are also other cool software projects like PythonCAD that use PyGTK:
It woudl be more work to switch yet again, but I find just about anything
can be made right if you are willing to start over a couple of times. :-)
Or, in short, having done the sensible thing of deciding to "Run away!" to
TK when faced with all the choices in the "Elementary graphics library"
thread, I'm wondering now whether the "Holy Hand Grenade" sacred relic
Brother GTK Maynard from Cairo carries:
could get the PataPata entourage safely past the killer rabbit of
cross-platform issues. :-)
I'm certainly not the only one asking that question right around now:
I've looked in the edusig list's archive and pyGTK is mentioned in about
30 posts over about six thread. Dave Reed on 12/26/2004 05:30 PM was very
encouraging of is a year and a half ago.
"I've used it on Linux/Solaris, Windows XP and Mac OS X and it works fine
on all of them. If I was coding for Windows only, I'd probably pick a
different widget set, but since I have little interest in programming
for Windows right now, I think glade/gtk is a great combination."
So it seems like by now it should be a fairly safe choice?
So, my question to educators or parents here using Mac and Windows is, are
you willing to go to the trouble (or have you already?) to make sure PyGTK
and a >= 2.8 GTK are running on your system at school or at home *if*
there was an application you really wanted to use? Would using PyGTK &
PyCairo & pygtkglext be more a show stopper or an incentive? I'm not
saying you would do it right now, just more, would you or could you do it
if you really wanted to? If so, or if there is at least a sense that it is
possible, I think I will be very tempted to (once again) make another
version of PataPata (PySqueak) that is GTK oriented. I've never tried to
use PyGTK on the Mac or Windows, so any feedback on it's current use in an
educational context of for packages you use for other things would be
appreciated (i.e. do you already use packages that depend on PyGTK?)
(*) The TK version still has a bug retrieving text from a multi-line TK
text box. And everything is sloppily floating around. And no save/load
world buttons yet.
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