Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!iuvax!purdue!ames!uhccux!munnari.oz.au!jkjl
From: jkjl@munnari.oz.au (John Keong-Jin Lim)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Desk Accessories, WaitNextEvent
Keywords: DAs WaitNextEvent
Message-ID: <1821@munnari.oz.au>
Date: 7 Aug 89 05:25:23 GMT
References: <4839@tank.uchicago.edu>
Reply-To: jkjl@munmurra.UUCP (John Keong-Jin Lim)
Organization: Comp Sci, University of Melbourne
Lines: 56

In article <4839@tank.uchicago.edu> stuart@tartarus.uchicago.edu (Stuart A. Kurtz) writes:
>I've had a few troubles with the interaction between DAs and my Application
>Code.  As near as I can tell (look at the Finder), I'm not alone ...

>Since I don't seem to get a recognizable event, I assume the implicit
>SystemEvent() in WNE/GNE is feeding the event to the DA, and then coercing
>it into a null event, even though the DA couldn't handle it.
>
>solution is to ignore the problem, and hope it will go away in System 7.

I agree to this solution - don't waste mental energy on trying to bypass
a design decision that apple made.

>
>My second problem has to do with the sleep parameter of WNE.  The
>"Programmer's Guide to Multifinder" claims that I don't have to worry about
>calling SystemTask(), as WNE will handle it.  Unfortunately, this just
>isn't so.  Consider the following fragment:
>
>	WaitNextEvent(--,--,0xFFFFFFFF,--);
>

There is a tech note that says you mustnt set the sleep parameter above
a certain magic number (100, 1000 ?) if you are running a pre-6.0 system.

>This is the sort of thing that's recommended if you don't need idle events.
>Now, if you open the AlarmClock DA in the application, guess what?  Right,
>and on the first guess!  It doesn't get updated.  Similarly (and more
>seriously) , the Moire clock doesn't update either.
>

Glad you prefer my clock to superclock's ! This is a serious MF bug/feature
problem. This is why Moire 2 is so jerky in some applications. The sleep
param is set too high (ie Finder under MF). Moire 3 fixes it by patching
WaitNextEvent and resetting the sleep longint to something shorter like
12 ticks when the screen saver is activated. WNE is not modified when
the screensaver is inactive, so the clock wont be updated still i'm afraid.

>This is a bit harder to fix.  Right now I'm leaning towards some system
>tuning parameters in a "Preferences..." dialog.  99.44% of the time,
>sleeping for a second in the foreground and forever in the background will
>be correct; but I'm fastidious enough to want to handle the other .56%
>correctly.  [Which suggests an interesting question about Ivory Soap ...]

From my experience, the user doesnt care nor notice the 0.56% improvement
in trivial things. Improve the user interface though and the rewards are
immediate and obvious (ie. a progress bar for long computations is a waste
of CPU time, but psychologically it makes the darn thing faster somehow).

	john lim
	Author of Moire

ps : Moire 3 has been posted to info-mac and have asked the moderators to
forward it to comp.binaries.mac. New features include improved user interface,
better colour animation and control, configurable sleep/wake rects and
run on shut down mode for large labs.