WCK and PIL
I've written an app using the wck library (widget construction kit, see http://www.effbot.org), in addition to the wckGraph module. What I'd like to do, is take the output of one of my windows (happens to be a graph), and save it as a *.png or *.gif. I was planning on using the PIL for this. I'd like to use the code I have as is, without re- writing all the graphic calls to use PIL methods. WCK uses its own "pixmap" class for storing images in memory. I can't find any documentation or class reference for pixmap and what I find in the source is confusing. Does anyone have any direct experience with these libraries that can tell me that there's some super easy thing I'm missing? I'd love it if the wck pixmap is compatible with PIL. I don't have the time to mess with it unless I know its going to work. -- http://mail.python.org/mailman/listinfo/python-list
Re: WCK and PIL
On Feb 6, 10:19 pm, Nobody wrote: > On Fri, 05 Feb 2010 21:05:53 -0800, darnzen wrote: > > I've written an app using thewcklibrary (widget construction kit, > > seehttp://www.effbot.org), in addition to the wckGraph module. What > > I'd like to do, is take the output of one of my windows (happens to be > > a graph), and save it as a *.png or *.gif. I was planning on using the > >PILfor this. I'd like to use the code I have as is, without re- > > writing all the graphic calls to usePILmethods. > > >WCKuses its own "pixmap" class for storing images in memory. I can't > > find any documentation or class reference for pixmap and what I find > > in the source is confusing. > > AWCKpixmap is a "draw object" whose underlying drawable is a pixmap > (i.e. a Tk pixmap, which is the platform's native "chunk of video memory" > pixmap type) rather than a window. > > From the source code,WCKdoesn't appear to offer any way to retrieve the > pixel data (i.e. there's no way to do the opposite of draw.paste()). I found a description of how to use a WCK drawing interface to draw into a PIL image. (http://effbot.org/zone/pil-draw-wck.htm) but I'm not sure how to use that class (SimpleDraw) to allow me to use existing WCK code. Should I use it as a "mix in" to overwrite base methods via inheritance? class MyClass(SimpleDraw, Widget): pass -- http://mail.python.org/mailman/listinfo/python-list
staticmethod and namespaces
Having an odd problem that I solved, but wondering if its the best solution (seems like a bit of a hack). First off, I'm using an external DLL that requires static callbacks, but because of this, I'm losing instance info. It will make more sense after I diagram it: #Module main.py class App: def sperg(self): pass app = App() [main loop and such] - # Module A.py import main class Foo: @staticmethod chum(nType, nPtr): # Need to access function / data in app instance app.sperg(nType, nPtr) -- http://mail.python.org/mailman/listinfo/python-list
staticmethod and namespaces
Having an odd problem that I solved, but wondering if its the best solution (seems like a bit of a hack). First off, I'm using an external DLL that requires static callbacks, but because of this, I'm losing instance info. It could be import related? It will make more sense after I diagram it: #Module main.py from A import * class App: def sperg(self): self.a = A() app = App() [main loop and such] - # Module A.py import main class Foo: Selves=[] def __init__(self): Foo.Selves.append(self) @staticmethod def chum_callback(nType, nP): # Need to access function / data in app instance app.sperg(nP) # Need to access func data in Foo # I'm pulling 'self' ouf of list made in constructor self = Foo.getSelf(nP) def getSelf(nP): return self.Selves[nP] - So basically I added a list of instances to the base class so I can get at them from the staticmethod. What's bothering me the most is I can't use the global app instance in the A.py module. How can I get at the app instance (currently I'm storing that along with the class instance in the constructor)? Is there another way to do this that's not such a hack? Sorry for the double / partial post :( -- http://mail.python.org/mailman/listinfo/python-list
Re: staticmethod and namespaces
On Feb 26, 3:15 am, "Diez B. Roggisch" wrote: > Am 26.02.10 06:07, schrieb darnzen: > > > > > > > Having an odd problem that I solved, but wondering if its the best > > solution (seems like a bit of a hack). > > > First off, I'm using an external DLL that requires static callbacks, > > but because of this, I'm losing instance info. It could be import > > related? It will make more sense after I diagram it: > > > #Module main.py > > from A import * > > > class App: > > def sperg(self): > > self.a = A() > > > app = App() > > [main loop and such] > > - > > # Module A.py > > import main > > class Foo: > > Selves=[] > > def __init__(self): > > Foo.Selves.append(self) > > @staticmethod > > def chum_callback(nType, nP): > > # Need to access function / data in app instance > > app.sperg(nP) > > # Need to access func data in Foo > > # I'm pulling 'self' ouf of list made in constructor > > self = Foo.getSelf(nP) > > > def getSelf(nP): > > return self.Selves[nP] > > > - > > So basically I added a list of instances to the base class so I can > > get at them from the staticmethod. > > What's bothering me the most is I can't use the global app instance in > > the A.py module. > > > How can I get at the app instance (currently I'm storing that along > > with the class instance in the constructor)? > > Is there another way to do this that's not such a hack? > > > Sorry for the double / partial post :( > > Can you show how you pass the staticmethod to the C-function? Is the DLL > utilized by ctypes? > > I don't see any reason you couldn't use a bound method, which would give > you your self, instead relying on global state. > > Diez __main__.K << *facepalm* should of tried that! Yeah I'm using ctypes. The DLL callback set ups are as follows. The local callback is in the App namespace (in this case, some callbacks are in different modules as noted in OP), but still no access to self: #Function wrapper A.expCallback = WINFUNCTYPE(None, c_int, c_int, \ POINTER(Data_s))(A.Callback) #DLL call to register the local callback function DLLSetCallback(self.hID, A.SubID, EVENTID, A.expCallback) class A: #Local callback function @staticmethod def Callback(hID, SubID, Data): print 'I DON'T KNOW WHO I AM OR WHERE I CAME FROM!!' print 'BUT WITH hID, and SubID, I CAN FIGURE IT OUT' print 'IF I STORE A REFERENCE TO MYSELF IN A DICT' print 'USING KEY GENERATED FROM hID, SubID' pass I'm not sure why they need to be static callbacks, but the DLL doc's say "when using object based languages, such as c++, callback functions must be declared as static functions and not instance methods", and I couldn't get it to work without setting it up that way. I could probably have them all be "classless" functions, but with 100's of these, my namespace would be polluted up the wazoo, and I'd still have the problem that they wouldn't have access to instance methods / properties. -- http://mail.python.org/mailman/listinfo/python-list
Re: staticmethod and namespaces
On Feb 26, 1:12 am, Steven D'Aprano wrote: > On Thu, 25 Feb 2010 21:07:55 -0800, darnzen wrote: > > Having an odd problem that I solved, but wondering if its the best > > solution (seems like a bit of a hack). > > > First off, I'm using an external DLL that requires static callbacks, but > > because of this, I'm losing instance info. > [...] > > How can I get at the app instance (currently I'm storing that along with > > the class instance in the constructor)? Is there another way to do this > > that's not such a hack? > > Pass the instance explicitly: > > >>> class K(object): > > ... @staticmethod > ... def static(self, x, y): > ... print self, x, y > ...>>> k = K() > >>> k.static(k, 1, 2) > > <__main__.K object at 0xb7c2544c> 1 2 > > -- > Steven Unfortunately, since the callback is from the DLL which I didn't write, I can not change what is passed to the function. Also, the DLL has no idea about my local namespace. The DLL typically will pass back two integers (which I can set the values of when I register the callback), and some data. Currently Im' using these integers as keys in a local dict where I'm storing the instances. I suppose I could use the integers to store the high and low order bytes of a pointer to the instance, but not sure how to do that in Python (would be easy in c/c++). Also, I'm not sure how python memory management works, if it will move objects around and make things buggy. Also, that is definitely a hack and isn't very 'pythonesque' -- http://mail.python.org/mailman/listinfo/python-list
Re: staticmethod and namespaces
On Feb 26, 9:41 am, "Diez B. Roggisch" wrote: > Am 26.02.10 16:32, schrieb darnzen: > > > > > > > On Feb 26, 3:15 am, "Diez B. Roggisch" wrote: > >> Am 26.02.10 06:07, schrieb darnzen: > > >>> Having an odd problem that I solved, but wondering if its the best > >>> solution (seems like a bit of a hack). > > >>> First off, I'm using an external DLL that requires static callbacks, > >>> but because of this, I'm losing instance info. It could be import > >>> related? It will make more sense after I diagram it: > > >>> #Module main.py > >>> from A import * > > >>> class App: > >>> def sperg(self): > >>> self.a = A() > > >>> app = App() > >>> [main loop and such] > >>> - > >>> # Module A.py > >>> import main > >>> class Foo: > >>> Selves=[] > >>> def __init__(self): > >>> Foo.Selves.append(self) > >>> �...@staticmethod > >>> def chum_callback(nType, nP): > >>> # Need to access function / data in app instance > >>> app.sperg(nP) > >>> # Need to access func data in Foo > >>> # I'm pulling 'self' ouf of list made in constructor > >>> self = Foo.getSelf(nP) > > >>> def getSelf(nP): > >>> return self.Selves[nP] > > >>> - > >>> So basically I added a list of instances to the base class so I can > >>> get at them from the staticmethod. > >>> What's bothering me the most is I can't use the global app instance in > >>> the A.py module. > > >>> How can I get at the app instance (currently I'm storing that along > >>> with the class instance in the constructor)? > >>> Is there another way to do this that's not such a hack? > > >>> Sorry for the double / partial post :( > > >> Can you show how you pass the staticmethod to the C-function? Is the DLL > >> utilized by ctypes? > > >> I don't see any reason you couldn't use a bound method, which would give > >> you your self, instead relying on global state. > > >> Diez > > > __main__.K<< *facepalm* should of tried that! > > > Yeah I'm using ctypes. The DLL callback set ups are as follows. The > > local callback is in the App namespace (in this case, some callbacks > > are in different modules as noted in OP), but still no access to self: > > > #Function wrapper > > A.expCallback = WINFUNCTYPE(None, c_int, c_int, \ > > POINTER(Data_s))(A.Callback) > > > #DLL call to register the local callback function > > DLLSetCallback(self.hID, A.SubID, EVENTID, A.expCallback) > > > class A: > > #Local callback function > > �...@staticmethod > > def Callback(hID, SubID, Data): > > print 'I DON'T KNOW WHO I AM OR WHERE I CAME FROM!!' > > print 'BUT WITH hID, and SubID, I CAN FIGURE IT OUT' > > print 'IF I STORE A REFERENCE TO MYSELF IN A DICT' > > print 'USING KEY GENERATED FROM hID, SubID' > > pass > > > I'm not sure why they need to be static callbacks, but the DLL doc's > > say "when using object based languages, such as c++, callback > > functions must be declared as static functions and not instance > > methods", and I couldn't get it to work without setting it up that > > way. I could probably have them all be "classless" functions, but with > > 100's of these, my namespace would be polluted up the wazoo, and I'd > > still have the problem that they wouldn't have access to instance > > methods / properties. > > The above code can't work with self, because you use > > A.expCallback > > which at best can of course be a classmethod. > > You need to instead invoke DLLSetCallback with a bound method, like this > > a = A() > DLLSetCallback(self.hID, A.SubID, EVENTID, a.expCallback) > > Also, the DLL-docs seem to refer to *C* or *C++*, where the concept of > static functions is differently. If ctypes manages to get *some* > callback passed, I'm 100% positive that it can pass *any* callable you > like, including bound methods. > > Diez This was originally how my code was set up, invoking with the bound methods, but it didn't work (crashing and bizzaro errors) and I was pulling my hair out. Then I read the documentation and changed it to static methods and everything started working. Believe me, I totally understand how using bound methods would make this problem go away. -- http://mail.python.org/mailman/listinfo/python-list
Re: staticmethod and namespaces
On Feb 26, 9:41 am, "Diez B. Roggisch" wrote: > Am 26.02.10 16:32, schrieb darnzen: > > > > > > > On Feb 26, 3:15 am, "Diez B. Roggisch" wrote: > >> Am 26.02.10 06:07, schrieb darnzen: > > >>> Having an odd problem that I solved, but wondering if its the best > >>> solution (seems like a bit of a hack). > > >>> First off, I'm using an external DLL that requires static callbacks, > >>> but because of this, I'm losing instance info. It could be import > >>> related? It will make more sense after I diagram it: > > >>> #Module main.py > >>> from A import * > > >>> class App: > >>> def sperg(self): > >>> self.a = A() > > >>> app = App() > >>> [main loop and such] > >>> - > >>> # Module A.py > >>> import main > >>> class Foo: > >>> Selves=[] > >>> def __init__(self): > >>> Foo.Selves.append(self) > >>> �...@staticmethod > >>> def chum_callback(nType, nP): > >>> # Need to access function / data in app instance > >>> app.sperg(nP) > >>> # Need to access func data in Foo > >>> # I'm pulling 'self' ouf of list made in constructor > >>> self = Foo.getSelf(nP) > > >>> def getSelf(nP): > >>> return self.Selves[nP] > > >>> - > >>> So basically I added a list of instances to the base class so I can > >>> get at them from the staticmethod. > >>> What's bothering me the most is I can't use the global app instance in > >>> the A.py module. > > >>> How can I get at the app instance (currently I'm storing that along > >>> with the class instance in the constructor)? > >>> Is there another way to do this that's not such a hack? > > >>> Sorry for the double / partial post :( > > >> Can you show how you pass the staticmethod to the C-function? Is the DLL > >> utilized by ctypes? > > >> I don't see any reason you couldn't use a bound method, which would give > >> you your self, instead relying on global state. > > >> Diez > > > __main__.K<< *facepalm* should of tried that! > > > Yeah I'm using ctypes. The DLL callback set ups are as follows. The > > local callback is in the App namespace (in this case, some callbacks > > are in different modules as noted in OP), but still no access to self: > > > #Function wrapper > > A.expCallback = WINFUNCTYPE(None, c_int, c_int, \ > > POINTER(Data_s))(A.Callback) > > > #DLL call to register the local callback function > > DLLSetCallback(self.hID, A.SubID, EVENTID, A.expCallback) > > > class A: > > #Local callback function > > �...@staticmethod > > def Callback(hID, SubID, Data): > > print 'I DON'T KNOW WHO I AM OR WHERE I CAME FROM!!' > > print 'BUT WITH hID, and SubID, I CAN FIGURE IT OUT' > > print 'IF I STORE A REFERENCE TO MYSELF IN A DICT' > > print 'USING KEY GENERATED FROM hID, SubID' > > pass > > > I'm not sure why they need to be static callbacks, but the DLL doc's > > say "when using object based languages, such as c++, callback > > functions must be declared as static functions and not instance > > methods", and I couldn't get it to work without setting it up that > > way. I could probably have them all be "classless" functions, but with > > 100's of these, my namespace would be polluted up the wazoo, and I'd > > still have the problem that they wouldn't have access to instance > > methods / properties. > > The above code can't work with self, because you use > > A.expCallback > > which at best can of course be a classmethod. > > You need to instead invoke DLLSetCallback with a bound method, like this > > a = A() > DLLSetCallback(self.hID, A.SubID, EVENTID, a.expCallback) > > Also, the DLL-docs seem to refer to *C* or *C++*, where the concept of > static functions is differently. If ctypes manages to get *some* > callback passed, I'm 100% positive that it can pass *any* callable you > like, including bound methods. > > Diez Thinking about it some more, I believe I understand why it has to be staticfunction. To use an bound method would require the wrapper to include a reference to the instance as follows: A.expCallback = WINFUNCTYPE(None, POINTER(A), c_int, c_int, \ POINTER(Data_s))(a.Callback) Since a = A(); a.foo() is really A.foo(self). The problem here is that A is not a ctypes object and I can't change what arguments the DLL uses in the callback in any case. Rewording my thoughts: a bound method callback would require 'self' to be the first argument. I can not make the DLL include 'self' as it doesn't know anything about the objects in my program. Since I can't pass 'self', it has to be a staticmethod. -- http://mail.python.org/mailman/listinfo/python-list
Re: staticmethod and namespaces
On Feb 26, 10:20 am, "Diez B. Roggisch" wrote: > Am 26.02.10 17:08, schrieb Diez B. Roggisch: > > > > > > > Am 26.02.10 16:57, schrieb darnzen: > >> On Feb 26, 9:41 am, "Diez B. Roggisch" wrote: > >>> Am 26.02.10 16:32, schrieb darnzen: > > >>>> On Feb 26, 3:15 am, "Diez B. Roggisch" wrote: > >>>>> Am 26.02.10 06:07, schrieb darnzen: > > >>>>>> Having an odd problem that I solved, but wondering if its the best > >>>>>> solution (seems like a bit of a hack). > > >>>>>> First off, I'm using an external DLL that requires static callbacks, > >>>>>> but because of this, I'm losing instance info. It could be import > >>>>>> related? It will make more sense after I diagram it: > > >>>>>> #Module main.py > >>>>>> from A import * > > >>>>>> class App: > >>>>>> def sperg(self): > >>>>>> self.a = A() > > >>>>>> app = App() > >>>>>> [main loop and such] > >>>>>> - > >>>>>> # Module A.py > >>>>>> import main > >>>>>> class Foo: > >>>>>> Selves=[] > >>>>>> def __init__(self): > >>>>>> Foo.Selves.append(self) > >>>>>> @staticmethod > >>>>>> def chum_callback(nType, nP): > >>>>>> # Need to access function / data in app instance > >>>>>> app.sperg(nP) > >>>>>> # Need to access func data in Foo > >>>>>> # I'm pulling 'self' ouf of list made in constructor > >>>>>> self = Foo.getSelf(nP) > > >>>>>> def getSelf(nP): > >>>>>> return self.Selves[nP] > > >>>>>> - > >>>>>> So basically I added a list of instances to the base class so I can > >>>>>> get at them from the staticmethod. > >>>>>> What's bothering me the most is I can't use the global app > >>>>>> instance in > >>>>>> the A.py module. > > >>>>>> How can I get at the app instance (currently I'm storing that along > >>>>>> with the class instance in the constructor)? > >>>>>> Is there another way to do this that's not such a hack? > > >>>>>> Sorry for the double / partial post :( > > >>>>> Can you show how you pass the staticmethod to the C-function? Is > >>>>> the DLL > >>>>> utilized by ctypes? > > >>>>> I don't see any reason you couldn't use a bound method, which would > >>>>> give > >>>>> you your self, instead relying on global state. > > >>>>> Diez > > >>>> __main__.K<< *facepalm* should of tried that! > > >>>> Yeah I'm using ctypes. The DLL callback set ups are as follows. The > >>>> local callback is in the App namespace (in this case, some callbacks > >>>> are in different modules as noted in OP), but still no access to self: > > >>>> #Function wrapper > >>>> A.expCallback = WINFUNCTYPE(None, c_int, c_int, \ > >>>> POINTER(Data_s))(A.Callback) > > >>>> #DLL call to register the local callback function > >>>> DLLSetCallback(self.hID, A.SubID, EVENTID, A.expCallback) > > >>>> class A: > >>>> #Local callback function > >>>> @staticmethod > >>>> def Callback(hID, SubID, Data): > >>>> print 'I DON'T KNOW WHO I AM OR WHERE I CAME FROM!!' > >>>> print 'BUT WITH hID, and SubID, I CAN FIGURE IT OUT' > >>>> print 'IF I STORE A REFERENCE TO MYSELF IN A DICT' > >>>> print 'USING KEY GENERATED FROM hID, SubID' > >>>> pass > > >>>> I'm not sure why they need to be static callbacks, but the DLL doc's > >>>> say "when using object based languages, such as c++, callback > >>>> functions must be declared as static functions and not instance > >>>> methods", and I couldn't get it to work without setting it up that > >>>> way. I could pr
