- Hewlett-Packard Printer User Guide

Using the VPO Application Programming Interfaces
The VPO Interfaces
Chapter 4 183
Access to Message Events
If an application registers for message events of the OPCSVIF_MSG_
EVENTS interface, the read queue for this interface instance is created
by VPO and accessed by the client, see Figure 4-8 on page 187. The
display manager registers the instance and writes all desired message
events to this queue. To use this interface, it is not necessary to enable it
in the configuration of the management server. The only restriction is
that the application must run with root permissions on the management
server.
You can get the following message events by way of the Message Event
Interface:
Table 4-2 Message Event Flags
Description Event Flag
All message events OPC_MSG_EVENT_ALL
Message attributes changed OPC_MSG_EVENT_CHANGE
Message in active browser acknowledged OPC_MSG_EVENT_ACK
Message in history browser
unacknowledged
OPC_MSG_EVENT_UNACK
Message owned OPC_MSG_EVENT_OWN
Message disowned OPC_MSG_EVENT_DISOWN
Annotation added OPC_MSG_EVENT_ANNO
Annotation deleted OPC_MSG_EVENT_NO_ANNO
Message escalated to another server OPC_MSG_EVENT_ESCALATED
Message escalated from another server OPC_MSG_EVENT_ESCALATED_FROM
Automatic action started OPC_MSG_EVENT_AA_START
Automatic action finished OPC_MSG_EVENT_AA_END
Operator-initiated action started OPC_MSG_EVENT_OA_START
Operator-initiated action finished OPC_MSG_EVENT_OA_END