Mixing Txinter and Pygame

[Tim Knauf]

Hi everyone, I'm glad to have found this list.

I've written a small script for my own use which, amongst other things,
captures mouse click information from a window containing an image. I
used Pygame to manage the image window, as it was the easiest way to
implement the functionality I needed. The surrounding interface windows
(there are two) are constructed with Tkinter.

Despite their unholy union, Pygame and Tkinter seem, generally, to
cooperate. I'm using this main loop to update one, then the other:

while 1:
gameLoop() # This function pumps the Pygame events and checks for
mouse and keyboard events
pygame.time.wait(10)
mainwin.update() # mainwin is an instance of Application class,
which is a child of Tkinter.frame

I have my interface set up so that when *any* of the windows' close
boxes are clicked, this function will be called:

# This portion of the Pygame loop calls doquit() when it gets a 'QUIT'
event...
def gameLoop():
pygame.event.pump()
for event in pygame.event.get():
if event.type == QUIT:
doquit()
# Etc.

# And this portion of the Tkinter interface sets the
WM_DELETE_WINDOW protocol to call doquit()
def createWidgets(self):
self.title("Region Management")
self.geometry('+830+8')
self.protocol("WM_DELETE_WINDOW", doquit)
# Etc.

# A temporary file is removed, and both Pygame and Tkinter are
instructed to quit
def doquit():
if os.access('recalc.tmp', os.F_OK):
os.remove('recalc.tmp')
pygame.quit()
mainwin.master.destroy()

Perhaps you've begun to see where I might be having problems. You see,
if I close the script by closing the Pygame window, I get this exception:

Traceback (most recent call last):
File "D:\Development\Python\sludge helpers\addScreenRegion
helper.pyw", line 363, in ?
mainwin.update()
File "C:\Python24\lib\lib-tk\Tkinter.py", line 859, in update
self.tk.call('update')
TclError: can't invoke "update" command: application has been destroyed

Conversely, if I close the application by closing a Tkinter window, I
get this exception:

Traceback (most recent call last):
File "D:\Development\Python\sludge helpers\addScreenRegion
helper.pyw", line 361, in ?
gameLoop()
File "D:\Development\Python\sludge helpers\addScreenRegion
helper.pyw", line 203, in gameLoop
pygame.event.pump()
error: video system not initialized

Obviously, Pygame doesn't like Tkinter telling it to quit (when it's
trying to do something from its internal loop) and vice versa. Is there
a simple way that I can avoid getting these exceptions on exit, or have
I taken the wrong approach? Everything else appears to work fine. Please
do excuse me if this seems a silly question, as I'm fairly new to Python
and Pygame, and a total novice when it comes to Tkinter.

On a side note, has anyone else found the Tkinter documentation awfully
obscure? I've found Python a joy to learn about, and Pygame's tutorials
are a lot of fun. I can't say the same for Tkinter, and found myself
having to do many Google searches before I uncovered information I could
put to use. Has anyone found any high-quality (online) documentation
that proves me wrong? :^)

Thanks in advance,
Tim Knauf

[Eric Brunel]

On Tue, 22 Feb 2005 13:17:37 +1300, Tim Knauf <ti*@upperorbit.com> wrote:

Hi everyone, I'm glad to have found this list.

I've written a small script for my own use which, amongst other things,
captures mouse click information from a window containing an image. I
used Pygame to manage the image window, as it was the easiest way to
implement the functionality I needed. The surrounding interface windows
(there are two) are constructed with Tkinter.

Despite their unholy union, Pygame and Tkinter seem, generally, to
cooperate. I'm using this main loop to update one, then the other:

while 1:
gameLoop() # This function pumps the Pygame events and checks for
mouse and keyboard events
pygame.time.wait(10)
mainwin.update() # mainwin is an instance of Application class,
which is a child of Tkinter.frame

I have my interface set up so that when *any* of the windows' close
boxes are clicked, this function will be called:

# This portion of the Pygame loop calls doquit() when it gets a 'QUIT'
event...
def gameLoop():
pygame.event.pump()
for event in pygame.event.get():
if event.type == QUIT:
doquit()
# Etc.

# And this portion of the Tkinter interface sets the
WM_DELETE_WINDOW protocol to call doquit()
def createWidgets(self):
self.title("Region Management")
self.geometry('+830+8')
self.protocol("WM_DELETE_WINDOW", doquit)
# Etc.

# A temporary file is removed, and both Pygame and Tkinter are
instructed to quit
def doquit():
if os.access('recalc.tmp', os.F_OK):
os.remove('recalc.tmp')
pygame.quit()
mainwin.master.destroy()

Perhaps you've begun to see where I might be having problems. You see,
if I close the script by closing the Pygame window, I get this exception:

Traceback (most recent call last):
File "D:\Development\Python\sludge helpers\addScreenRegion
helper.pyw", line 363, in ?
mainwin.update()
File "C:\Python24\lib\lib-tk\Tkinter.py", line 859, in update
self.tk.call('update')
TclError: can't invoke "update" command: application has been destroyed

Conversely, if I close the application by closing a Tkinter window, I
get this exception:

Traceback (most recent call last):
File "D:\Development\Python\sludge helpers\addScreenRegion
helper.pyw", line 361, in ?
gameLoop()
File "D:\Development\Python\sludge helpers\addScreenRegion
helper.pyw", line 203, in gameLoop
pygame.event.pump()
error: video system not initialized

Obviously, Pygame doesn't like Tkinter telling it to quit (when it's
trying to do something from its internal loop) and vice versa. Is there
a simple way that I can avoid getting these exceptions on exit, or have
I taken the wrong approach? Everything else appears to work fine. Please
do excuse me if this seems a silly question, as I'm fairly new to Python
and Pygame, and a total novice when it comes to Tkinter.
Well, since these are just exceptions, a simple try... except block would be fine, and you can even figure out the reason for the exception. Here is what I'd do:
- when you create your Tkinter main window, initialize an attribute that you'll use to see if the application has quit, e.g mainwin.hasQuit = False
- rewrite doquit this way:
def doquit():
if os.access('recalc.tmp', os.F_OK):
os.remove('recalc.tmp')
mainwin.hasQuit = True
pygame.quit()
- rewrite your custom event loop this way:
while 1:
gameLoop()
pygame.time.wait(10)
try:
mainwin.update()
except TclError:
if not mainwin.hasQuit:
raise

And: (1) your problem should go away; (2) the "real" exceptions you may get from Tkinter windows should not passed unnoticed.
On a side note, has anyone else found the Tkinter documentation awfully
obscure? I've found Python a joy to learn about, and Pygame's tutorials
are a lot of fun. I can't say the same for Tkinter, and found myself
having to do many Google searches before I uncovered information I could
put to use. Has anyone found any high-quality (online) documentation
that proves me wrong? :^)

Incomplete, but very useful: http://www.pythonware.com/library/tk...tion/index.htm
But the best reference documentation you'll ever find is the tcl/tk man pages, on-line here: http://www.tcl.tk/man/tcl8.4/TkCmd/contents.htm
It unfortunately requires to know how to convert the tcl/tk syntax to Python/Tkinter syntax, but it is actually quite easy (mainly read "option=value" when the tcl/tk documentation says "-option value")

HTH
- Eric Brunel -

[Tim Knauf]

Eric Brunel wrote:

Well, since these are just exceptions, a simple try... except block
would be fine, and you can even figure out the reason for the
exception. Here is what I'd do:
- when you create your Tkinter main window, initialize an attribute
that you'll use to see if the application has quit, e.g
mainwin.hasQuit = False
- rewrite doquit this way:
def doquit():
if os.access('recalc.tmp', os.F_OK):
os.remove('recalc.tmp')
mainwin.hasQuit = True
pygame.quit()
- rewrite your custom event loop this way:
while 1:
gameLoop()
pygame.time.wait(10)
try:
mainwin.update()
except TclError:
if not mainwin.hasQuit:
raise

And: (1) your problem should go away; (2) the "real" exceptions you
may get from Tkinter windows should not passed unnoticed.

I adapted your suggestion slightly, and my final event loop looks like this:

while not mainwin.hasQuit:
try:
gameLoop()
except pygame.error:
if not mainwin.hasQuit:
raise
pygame.time.wait(10)
try:
mainwin.update()
except Tkinter.TclError:
if not mainwin.hasQuit:
raise

That seems to work perfectly. Thanks, Eric!
Incomplete, but very useful:
http://www.pythonware.com/library/tk...tion/index.htm
But the best reference documentation you'll ever find is the tcl/tk
man pages, on-line here: http://www.tcl.tk/man/tcl8.4/TkCmd/contents.htm
It unfortunately requires to know how to convert the tcl/tk syntax to
Python/Tkinter syntax, but it is actually quite easy (mainly read
"option=value" when the tcl/tk documentation says "-option value")

Ah, yes, I had managed to find the pythonware.com pages in my travels,
and they proved quite helpful. Good to know about the man pages, too.
(When I'm starting on a language feature, though, I usually find I learn
a lot more from worked examples than from straight command information.
I have friends who are just the opposite, so I suppose it's just a
learning styles thing.)

wxPython seems to be highly regarded. I might experiment with that for
my next project, and see which framework I like the best. Thanks again.

[Eric Brunel]

On Wed, 23 Feb 2005 10:23:09 +1300, Tim Knauf <bu**@upperorbit.com> wrote:
[snip]

(When I'm starting on a language feature, though, I usually find I learn
a lot more from worked examples than from straight command information.

You may be interested in Tkinter best kept secret: the example scripts in the Demo/tkinter sub-directory of the Python source installation. It mainly covers the basics, but may be quite helpful when you start.

HTH
- eric -