Path: utzoo!mnetor!uunet!husc6!mit-eddie!ll-xn!ames!amdahl!nsc!voder!apple!dgold
From: dgold@apple.UUCP (David Goldsmith)
Newsgroups: comp.sys.mac
Subject: Re: MultiFInder+MultiVideo+MultiMachine
Message-ID: <7138@apple.UUCP>
Date: 6 Jan 88 18:38:21 GMT
References: <22366@ucbvax.BERKELEY.EDU> <22367@ucbvax.BERKELEY.EDU>
Reply-To: dgold@apple.UUCP (David Goldsmith)
Organization: Apple Computer Inc., Cupertino, USA
Lines: 29

Thanks to David Oster for his article on dealing with window restoration
on multiple monitors.  I just wanted to add one thing:

For any loop over the set of GDevices on a multiple-monitor machine,
it is necessary to test the GDevice for being a screen and being active
before you assume it is a monitor you can put a window on.  Non-screen
GDevices (such as printers or off-screen GDevices) can appear in the list,
and even screen devices can appear but be inactive.  The latter case occurs
when the user connects a new monitor but has not yet configured it via
the Monitors cdev.  QuickDraw will not normally draw on an inactive device.

So any loop you have (such as the one David gave) should contain the
following test:

if (((**gd).gdFlags & (1<<screenDevice)) &&
	(((**gd).gdFlags) & (1<<screenActive))) {
	... whatever you want ...
}

around whatever you want to do for each active monitor.

-- 
David Goldsmith
Apple Computer, Inc.

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