[python-win32] Creating python com objects

[Roger Upole]

Tim Golden wrote:
> Alex Denham wrote:
>>       Parameters
>> 
>> /pDataObj/ : *PyIDataObject **
>>  
>> How do i link the IDataObject to the IDragTarget?
> 
> I don't know that you can, if you're asking: how do I
> find out where this is coming from?. I think the drag-drop
> technique is endpoint-agnostic. (A high-sounding phrase I've
> just invented).

Don't forget to trademark it !

> The most you can do is get hold of the data.
> Again, I think.

This is correct, the IDataObject interface is provided by the object
that's being dragged.  Unless you're also providing the dragged
object the interface should be opaque.

> 
> I'm out of my depth so I'm hoping that Roger or Mark
> or other more knowledgeable people can chip in at this point
> and help.
> 
> For the purposes of discussion, I attach below my test harness
> code which creates a simple window and registers a simple
> IDropTarget object against it.
> 
> Sorry to be no more help than this.
> TJG
> 
> <code>
> import os, sys
> import win32gui
> import win32con
> import pythoncom
> 
> CLSID = '{89DD545A-2C83-4103-AFE3-6CEB7FF5ECA4}'
> PROGID = "Tim.DropTarget"
> DESC = "Drop target handler for Tim's app"
> 
> class DropTarget:
>   _reg_clsid_ = CLSID
>   _reg_progid_ = PROGID
>   _reg_desc_ = DESC
>   _public_methods_ = ['DragEnter', 'DragOver', 'DragLeave', 'Drop']
>   _com_interfaces_ = [pythoncom.IID_IDropTarget]
> 
>   def DragEnter (self, data_object, key_state, point, effect):
>        pass
>   def DragOver (self, key_state, point, effect):
>        pass
>   def DragLeave (self):
>        pass
>   def Drop (self, data_object, key_state, point, effect):
>        pass
> 
> def create_window ():
>   def OnDestroy (hwnd, msg, wparam, lparam):
>     win32gui.PostQuitMessage (0)
> 
>   wc = win32gui.WNDCLASS ()
>   hinst = win32gui.GetModuleHandle(None)
>   wc.lpszClassName = "DragDrop"
>   wc.style = win32con.CS_VREDRAW | win32con.CS_HREDRAW;
>   wc.hCursor = win32gui.LoadCursor (0, win32con.IDC_ARROW)
>   wc.hbrBackground = win32con.COLOR_WINDOW
>   wc.lpfnWndProc = {win32con.WM_DESTROY : OnDestroy}
>   classAtom = win32gui.RegisterClass (wc)
>   style = win32con.WS_VISIBLE | \
>     win32con.WS_OVERLAPPED | win32con.WS_SYSMENU
>   return win32gui.CreateWindow (
>     classAtom,
>     "Drag & Drop demo",
>     style,
>     0, 0, 100, 100,
>     0, 0, hinst, None
>   )
> 
> if __name__ == '__main__':
>   pythoncom.OleInitialize ()
>   drop_target = pythoncom.WrapObject (
>     DropTarget,
>     pythoncom.IID_IDropTarget,
>     pythoncom.IID_IDropTarget
>   )
>   pythoncom.RegisterDragDrop (create_window (), drop_target)
>   win32gui.PumpMessages ()
> 
> </code>

There's a little extra work you have to do for WrapObject to work locally.
See \win32comext\authorization\demos\EditSecurity.py for an example.

        Roger