GETMESSAGE

GETMESSAGE

This macro retrieves and dispatches messages. If a message handler is installed, the message is forwarded to the handler to perform message processing.

If the argument "forever" equals 0, all messages which were not processed by a handler, are returned. If "forever" equals 1, all not processed messages are ignored and GETMESSAGE stays active until the application is finished (variable APPMODE<1). Most applications uses the call "getmessage 1 1" to implement the main message loop.

The argument "queued" controls the processing of messages stored in the secondary queue. This queue is filled with messages which can not be processed at the time. The processing of the secondary queue should be disabled in (sub-) message loops which queues (unknown) messages by calling the macro MSGQUEUE.

The argument "nodispatch" can be set to 1 to disable message handlers. In this case all messages are returned and must be precessed by the caller.

Usage:

GETMESSAGE [ queued forever nodispath ]

Parameters:

queued

Process messages from secondary queue (0=no, 1=yes; def.=1)

forever

Run while application is active, do not return not-processed (0=no, 1=yes; def.=0)

nodispatch

Disable message dispatching, return all messages (0=no, 1=yes; def.=0)

Result:

The shell variable RESULT is set to the first not processed message ("type name id par") or "* * * *" if application is finished

Examples:

Define a message handler and then process messages until the application is closed.

setmsghandler * * mh
do while $AppMode != 0
        getmessage
end
setmsghandler * *

Notes:

PostMessage