Drag and drop from NSE to Total Commander panel fails

[Dec]

I develop Namespace shell extension allows to browse my own archive type in Explorer. When I drag and drop file from NSE to TC nothing happens. I use the followings formats in IDataObject:

CF_FILEDESCRIPTORW
CF_FILEDESCRIPTORA
CF_FILECONTENTS
CF_ITEMIDLIST

In logs I see that TC request CF_ITEMIDLIST format first. But CF_ITEMIDLIST points on virtual files and TC stops dropping. But when I remove CF_ITEMIDLIST from format list TC requests CF_FILEDESCRIPTORW/CF_FILECONTENTS and everything works fine.

To Ghisler:

Could you change the logic of processing of IDataObject? Is it possible to process CF_FILEDESCRIPTORW/CF_FILECONTENTS when processing of CF_ITEMIDLIST fails?

[Horst.Epp]

Why do you post such questions in the bugs forum ?
Just because TC doesn't like your own written software.
There are other forums for such questions

[Dec]

Why do you post such questions in the bugs forum ?

Because it looks like a bug in processing of Drag&Drop operation in TC.

[ghisler(Author)]

There is no documentation from Microsoft in which order Explorer processes drag&drop types. Therefore TC tries those first which return more useful data. Why doesn't CF_ITEMIDLIST return anything usable?

[Dec]

There is no documentation from Microsoft in which order Explorer processes drag&drop types.

I agree.

Therefore TC tries those first which return more useful data.

No problem. But TC does not continue work with other formats when work with CF_ITEMIDLIST fails. For example when I copy my IDataObect to clipboard TC pastes it correctly always. But in case of Drag&Drop it fails when CF_ITEMIDLIST presents.

Why doesn't CF_ITEMIDLIST return anything usable?

CF_ITEMIDLIST contains legal PItemIDList which points on virtual object which is not the part of real file system. This format is necessary for other destinations.

[ghisler(Author)]

CF_ITEMIDLIST contains legal PItemIDList which points on virtual object which is not the part of real file system. This format is necessary for other destinations.

This works with other programs - why shouldn't it work for real files, they are also virtual files (the opposite isn't always true). TC tries to get the IShellFolder for the parent, then get the IID_IContextMenu for the list of files and copy them via clipboard functions.