How to set win32clipboard data on CF_HDROP format?

Question

I am confronted to the loss of alpha channel when I try to send image to clipboard, none of the solutions described here worked with the software I am working with but when I copy paste png files into this software, the alpha channel seems to be preserved. Under this consideration, I want to simulate the Ctrl+C on files allowed by Windows Explorer. Using Clipview I found that the field 15 : CF_HDROP is relevant to my goal. tried to set this field using win32clipboard

import win32clipboard
win32clipboard.OpenClipboard(0)
file1="C:\\Users\\User\\Desktop\\test.png"
win32clipboard.SetClipboardData(15, file1)
win32clipboard.CloseClipboard()

I don't get any error doing this, but it does not work when I try to use this new clipboard content, because as described there tuple of unicode filenames must be stored in the CF_HDROP field.

I have no clue how to proceed. I also tried with file1= (unicode('C:\\Users\\User\\Desktop\\CANEVAS\\test.png'),) but I got this error:

TypeError: expected a readable buffer object.

Answer 1

The documentation for CF_HDROP says

The data consists of an STGMEDIUM structure that contains a global memory object. The structure's hGlobal member points to a DROPFILES structure as its hGlobal member.

win32clipboard.GetClipboardData has built-in support for CF_HDROP. It decodes the STGMEDIUM and DROPFILES structures to produce a tuple of file names.

The documentation does not state that SetClipboardData has the corresponding code to construct the STGMEDIUM and DROPFILES structures from a tuple of file names.

I don't know enough about Python or its FFI to know how straightforward it is to construct the structures and pass them to the SetClipboardData function. Or if there is an existing library that will do this for you.