Re: alternatives to mswgui

Robin Becker <[email protected]> writes:

> After trying unsuccessfully to determine the cause of leakage in the
> dynwin win32 backend I asked for an assist on comp.lang.python. Thomas
> Heller then suggested his alternative to calldll called ctypes.
> 
> After about three hours I made an alternate to dwgui.py/mswgui.py using
> his framework and this now also seems to work and more importantly it
> doesn't seem to leak. This is called ctmswgui.py. 
> 
> It's slighly more messy than dwgui (we have to be explicit about using
> the  A version or the W version of the win32 API), but there're only two
> modules _ctypes.pyd & ctypes.py and Thomas says he'll do the debugging
> if we encounter serious problems ;)

>>> import this
...
Explicit is better than implicit.
...

It is, of course, easy to hide the A/W problem away.
In fact, the idea I have is *not* to use it in this way:

  from ctypes import windll, WinError
  kernel32 = windll.kernel32

  handle = user32.GetModuleHandleA(None)
  # note the 'A' here            ^
  if handle == 0:
      raise WinError()
  # use the handle

instead I think one should do it in this way:

  from ctypes import windll, WinError
  kernel32 = windll.kernel32

  def HANDLE(value):
      # check if the return value is a valid handle
      if value == 0:
          raise WinError()
      return HANDLE

  GetModuleHandle = kernel32.GetModuleHandleA
  GetModuleHandle.restype = HANDLE

then you can use GetModuleHandle to your hearts content,
and you do not have to check for errors.

> 
> What do others think of the competing msw approaches (if anything).

Why not use both for a while amd decide later?

> -- 
> Robin Becker

Thomas



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