This function handles the file direct manipulation protocol for a given window. The window responds (DOR_DROP, usDefaultOp) to DM_DRAGOVER messages for items with a type matching the acceptable type string and with a rendering mechanism and format of <DRM_OS2FILE,DRF_UNKNOWN>. Not all dragged objects must match this criteria for the drop to be acceptable.
After the drop occurs, this function handles the conversation required to complete the direct manipulation operation for all acceptable objects. A DM_ENDCONVERSATION (DMFL_TARGETFAIL) message is sent to the source when an object is unacceptable.
When an error occurs during a move or copy, the caller is sent a DM_DRAGERROR message. The caller can take corrective action.
As the move or copy operation is successfully completed for each file, a DM_DRAGFILECOMPLETE message is sent to the caller. No message is sent when the operation fails.
The function returns TRUE if the operation is successful and FALSE if an error occurs.