Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: How to detect Option/Close under TransSkel?
Message-ID: <8414@hoptoad.uucp>
Date: 29 Aug 89 06:31:29 GMT
References: <253@castle.ed.ac.uk>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 61

In article <253@castle.ed.ac.uk> nick@lfcs.ed.ac.uk (Nick Rothwell) writes:
>I'm writing an application which needs to detect option/click and
>command/click on the close box of windows.

This is clearly some meaning of "need" with which I am not familiar.

>Unfortunately, TransSkel
>(which I'm using) doesn't deliver the event modifiers to me, but only
>the close event. I'm currently using a hack: after getting the close
>event, look at the key-map to see if the option/command keys are down.
>   Disadvantages:
>	o Hard-wired key numbers which may not be universal between machines;

Could be, but so much software uses the modifier keys and GetKeys that
it's awfully unlikely to change.  Still, better safe than screwed.

>	o Disallows command/key short-cut for close (think about it...);

Only if you use the Command key for something it's not intended for.

>	o It's a HACK.

So is hiding features of your program in obscure command and option key
combinations.  The best thing about the Mac interface is that software
advertises its features.  It should advertise *all* its features; on
other computers, you can get away with saying "you insert the date by
typing 'date', setting the mark to the front of the word, and pressing
cokebottle-delete to turn it into an internal variable reference".
Many people still try this kind of crap on the Mac, and it leads to bad
interfaces.  Put whatever special function it is you want in the menus
or in a button.  Hidden features -- just say no.

You forgot a disadvantage -- the key may already be up by the time
you check it.  So this method is not reliable.

>   Advantage:
>	o I don't have to make yet more alterations to my (already much
>	  customised) copy of TransSkel.

I'm not familiar with TransSkel (no FTP access) but I have a certain
amount of respect for DuBois as a programmer (if not as a theologian).
The reason he doesn't give you the modifier flag here is because this
kind of interfacing is anything but kosher.

(And yes, I know all about the Finder's option-close feature; it's one
of the many serious mistakes made in the Finder's interface.  You
should all know by now that applications from Apple are generally among
the most confusing and least standard.)

>I suspect that altering TransSkel yet again is the only true option.
>Just out of curiosity, how does MultiFinder detect Option when opening
>DAs in the application partition? Might it be this self same hack?

Why not say "atb getkeys" in Macsbug and find out?  I just did.  The
answer is yes.  And hack is the word.
-- 
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, tim@toad.com

"As I was walking among the fires of Hell, delighted with the enjoyments of
 Genius; which to Angels look like torment and insanity.  I collected some of
 their Proverbs..." - Blake, "The Marriage of Heaven and Hell"