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From: saj@chinet.chi.il.us (Stephen Jacobs)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: Right Mouse Button Programming
Summary: Either catch interrupts or poll the extended line A variable
Keywords: C, mouse, Mark Williams C
Message-ID: <1990Jul31.184807.25820@chinet.chi.il.us>
Date: 31 Jul 90 18:48:07 GMT
References: <1961@ncrcam.Cambridge.NCR.COM>
Organization: Chinet - Public Access UNIX
Lines: 11

There are 2 attractive ways to use both mouse buttons (that I know of).  When
Atari people have replied to such inquiries in the past, they've suggested
intercepting the mouse button interrupt vector, recording what the mouse
button state is, and passing control to the original mouse button handler.
Your program can read the recorded state at its convenience.  That method is
solid and supported, but I hate having a program in supervisor mode even a
microsecond longer than necessary.  There is a documented extended line-A
variable which tracks the state of the mouse buttons.  You can poll it
(possibly as part of the timer event handling of an evnt_multi() loop) and
act accordingly.
                                       Steve J.