[Pyobjc-dev] Casting to CGWindowID

[Matt W. <ma...@in...>]

Hi there,

I'm using the default PyObjC on Leopard.

I've used PyObjC before--very happy with it, thanks! To learn more,  
I've been attempting to port SonOfGrab to Python. It uses some new- 
to-10.5 window server methods that I want to get familiar with:

   http://developer.apple.com/samplecode/SonOfGrab/index.html

What I'm being stumped by is making an array that consists of  
CGWindowID types (CGWindowID is a uint32_t), rather than NSNumber.

It's probably really simple, I know, but I can't see it in the docs  
(and my Google-fu is poor today):

how do I force a number - in Python - to get cast as uint32_t when  
it's given to Obj C, instead of an NSNumber?

(I've put a little more info below.)

thanks,
Matt

#

My Python code is:

windowIds = [w[kWindowIDKey].unsignedIntValue() for w in  
sortedSelection]


The equivalent Obj C code is:

  // Now we Collect the CGWindowIDs from the sorted selection
  CGWindowID *windowIDs = calloc([sortedSelection count],  
sizeof(CGWindowID));
  int i = 0;
  for(NSMutableDictionary *entry in sortedSelection)
  {
    windowIDs[i++] = [[entry objectForKey:kWindowIDKey]  
unsignedIntValue];
  }
  // CGWindowListCreateImageFromArray expect a CFArray of  
*CGWindowID*, not CGWindowID wrapped in a CF/NSNumber
  // Hence we typecast our array above (to avoid the compiler warning)  
and use NULL CFArray callbacks
  // (because CGWindowID isn't a CF type) to avoid retain/release.
  CFArrayRef windowIDsArray = CFArrayCreate(kCFAllocatorDefault,  
(const void**)windowIDs, [sortedSelection count], NULL);
  free(windowIDs);

-- from http://developer.apple.com/samplecode/SonOfGrab/listing2.html