NAME

accept_target - accept a pending target request for a new segment

SYNOPSIS

vid:new_vid, aid:new_aid, int:cookie
accept_target( int:setw, int:seth )
accept_target( int:setw, int:seth, func:callback )

DESCRIPTION

A connected frameserver is provided with one segment by default, but additional ones can be requested. If that happens, a segment_request event is sent through to the callback associated with the frameserver. If this request goes unhandled in the callback implementation, a rejection reply will be sent. By calling accept_target in immediate response to a segment_request, a new segment will be allocated and sent to the frameserver. The type of this segment will follow the one present in the request, and it is the responsibility of the script to determine that this is one that is supported. To filter the segkind field, prefer to use a whitelisting approach. The optional arguments setw , seth can be used to change the initial dimensions of the new segment from the ones requested in the segreq event (see launch_target ). The frameserver can still perform a resize to ignore these values, but it saves a possible displayhint->resize cycle with the initial 1-2 frame setup latency that would impose. The optional argument callback sets the event handler for the new segment, but can also be changed with calls to target_updatehandler . On success, the function returns reference handles to the new audio and video resources, along with an identification token that might be used by the client for reparenting in viewport events.

NOTES

1

accept_target is context sensitive. This means that calling it outside a frameserver event-handler, or when there is no pending segment_request event, is a terminal state transition.

2

Possible segkind values for a subsegment are: "multimedia", "cursor", "terminal", "popup", "icon", "remoting", "game", "hmd-l", "hmd-r", "hmd-sbs-lr", "vm", "application", "clipboard", "browser", "encoder", "titlebar", "sensor", "debug", "accessibility".

3

The number of permitted segments etc. should be limited by available vids and other resources so that a malicious client cannot starve the serving arcan process. See the 'recursive_evil' security test case for more detail.

4

Subsegments are always bound to the primary segment, this means that attempts at complex hierarchies, such as a main- window with a popup window with a titlebar with an icon is not possible directly, though viewport hints can be used to describe such relations superficially.

EXAMPLE

function accept_target0()


      target_alloc("test", function(source, status)


            if (status.kind == "segment_request") then
-- possibly ignore request if supplied properties e.g.
-- dimensions or subtype is not permitted.


                  accept_target();


            end


      end)
end

SEE ALSO:

target_alloc(3)