Re: First draft, IO & event design

[Gordon Henriksen]

On May 24, 2004, at 15.20, Dan Sugalski wrote:
Event Ops
=========
The opcodes in this section are a combination of event requests and 
event handling ops. It doesn't include the IO ops--those are separate.

Most of the event request ops have two forms, one of which takes a 
callback PMC and user data PMC.

   checkevent
Explicitly check to see if there are any events pending in the event 
queue and, if so process one.
So, for GUI events, could calling into parrot and doing the following 
from the OS event handler work to synchronously dispatch an event?

        ... parrot-ify a mouse-moved event into $P5 ...
        post $P5
        checkevent
Hm. No. If there's already an event in the queue, then that won't 
work... :( Maybe this change, instead:

        polleventq(out Pevent)
        Shifts one event off of the queue into Pevent, or nulls Pevent.
        
        dispatch(in Pevent)
        Invokes the registered event handler(s) for Pevent.
Which makes checkevent really this:
        polleventq Py
        isnull Py, .NO_EVENT
        dispatch Py
.NO_EVENT:
—
Gordon Henriksen
IT Manager
ICLUBcentral Inc.
[EMAIL PROTECTED]