Custom Handlers for Listers: drop

This is a drag'n'drop event, and indicates that one or more entries have
been dropped into a lister.

The message arguments are:-

        Arg0 - "drop"              (a string indicating the event type)
        Arg1 - <handle>            (destination lister handle)
        Arg2 - <names>             (filenames)
        Arg3 - <handle>            (source lister handle)
        Arg4 - undefined
        Arg5 - <destination>       (full destination path)
        Arg6 - <qualifiers>        (string indicating qualifiers pressed
                                   - shift, alt, control keys, or whether drop
                                   was over a sub-directory)

The filenames are separated by spaces (if there is more than one), and will
be within quotes if the quotes keyword was specified for the
 lister set handler  command.

Arg5 contains the full destination path.  You can compare this against the
path of the destination lister (handle in Arg1) to see whether the drop was
into a sub-directory or into the lister itself.

You should not rely on the ARexx Word() function to traverse the list
of filenames because it does not support quotes and any name with a space
in it will cause your script to malfunction. 

If the files originated from another Opus 5 lister, Arg3 gives the handle
of that lister. If this is the case, and the fullpath option was not
specified for  lister set handler , only the filenames (and not their
paths) are supplied in Arg2 (you can get the source path using
 lister query path ). If Arg3 is null then the drop most likely originated
from Workbench, and the names in Arg2 include the full paths.

If the files are dropped over a sub-directory in the lister then Arg6 will
contain the qualifier 'subdrop', providing that the handler was invoked using
 lister set handler  with the subdrop keyword.