Functional specification
54
CDE/Motif PST
CDEnext
selection_display
A returned display connection against which the PDM selection should be
made. May be equal to
print_display
or
video_display
, or may
be a new display connection that the caller should close when done.
selection
A returned selection atom against which the conversion should be made.
target
A returned target atom against which the conversion should be made.
RETURN VALUE
NULL status if an error occured, non-NULL otherwise.
DESCRIPTION
XpGetAuthParams
is a convenience routine used to construct the necessary property information and
selection display connection information needed to initiate a transfer of display-connection authorization
information per the "PDM Selection Protocol". Once the information is constructed, the caller can manage
the creation of a property, the generation of a
SelectionRequest
, the receipt of a
SelectionNotify
event, and the subsequent transmission of authorization information. See
XpSendAuth
and
XpSendOneTicket
for more details.
If
NULL
is returned by
XpGetAuthParams
, then an error occured and all return values are invalid.
XpGetAuthParams
also implements the concept of an "alternate selection server". By changing the
name of the x-selection or by changing the X-Server upon which the selection is made, an alternate PDM
can be engaged. By default, the PDM owning the
PDM_MANAGER
x-selection on the Print X-Server is the
PDM engaged.
Setting the environment variable XPDMSELECTION causes
XpGetAuthParams
to use an alternate
selection name. If not set, the selection name
PDM_MANAGER
is used.
Setting the environment variable XPDMDISPLAY causes
XpGetAuthParams
to locate the selection on
an alternate X Server. If not set,
selection_display
(a returned parameter) is set equal to
print_display
. If set to one of the keywords
"print"
or
"video"
,
selection_display
is set
to
print_display
or
video_display
, respectively. If set to a valid
DISPLAY
-style string,
selection_display
may be set, as appropriate, to one of
print_display
,
video_display
, or
to a new display connection made from within
XpGetAuthParams
. Only in the single case where a new
display connection is made should the caller close
selection_display
using
XCloseDisplay(3)
.
ENVIRONMENT VARIABLES
See the above discussion regarding XPDMDISPLAY and XPDMSELECTION.
All environment variables are re-read each time
XpGetAuthParams
is called.