[python-win32] COM illegal argument puzzler

[Adam Pletcher]

A co-worker of mine is writing a tool to automate tasks in Photoshop, and found a win32 error we can't explain.  And possibly a bug.

The following script generates an error about how Select() can only take one-dimensional arrays:

import win32com.client
ps_app = win32com.client.Dispatch('Photoshop.Application')
ps_app.Documents.Add(128, 128, 72)
 
# select a 10x10 square in the upper left corner of the document
sel_area = ((0, 0), (10, 0), (10, 10), (0, 10), (0, 0))
ps_app.ActiveDocument.Selection.Select(sel_area)
 
The error: 
 
com_error: (-2147352567, 'Exception occurred.', (0, 'Adobe Photoshop', 'Illegal argument - argument 1\n- Only arrays with dimension 1 are supported', None, 0, -2147220262), None)
File "c:\Python_Scripts\COM\Photoshop\selectionTest.py", line 7, in <module>
  ps_app.ActiveDocument.Selection.Select(sel_area)
File "C:\Python25\Lib\site-packages\win32com\gen_py\E891EE9A-D0AE-4CB4-8871-F92C0109F18Ex0x9x0.py", line 2606, in Select
  , Type, Feather, AntiAlias)
 
The problem is that that method is documented as taking two dimensional arrays. Here's an exerpt from the Photoshop CS3 VBScript Ref doc:
 
docH = appRef.ActiveDocument.Width / 2
docV = appRef.ActiveDocument.Height / 2
selRegion = Array( Array( topLeftH * docH, topLeftV * docV), _
Array( topLeftH * docH + docH, topLeftV * docV), _
Array( topLeftH * docH + docH, topLeftV * docV + docV), _
Array( topLeftH * docH, topLeftV * docV + docV), _
Array( topLeftH * docH, topLeftV * docV))
appRef.ActiveDocument.Selection.Select(selRegion)
 
It makes sense that it has to take a sequence of two-element sequences, right?  Oddly enough, if you run the above code using the comtypes extensions instead of win32com, it works perfectly.  The first two lines then become:
 
import comtypes.client
ps_app = comtypes.client.CreateObject('Photoshop.Application')

Any ideas why this throws an exception with win32com.client/Dispatch?  Is this a bug?

Thanks in advance.

- Adam

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