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From: sirkm@ssyx.ucsc.edu (Greg Anderson)
Newsgroups: comp.sys.mac.hypercard
Subject: Drawing _on_top_of_ HyperCard's window
Keywords: polybuttons
Message-ID: <11005@saturn.ucsc.edu>
Date: 8 Mar 90 01:36:42 GMT
Sender: usenet@saturn.ucsc.edu
Reply-To: sirkm@ssyx.ucsc.edu (Greg Anderson)
Organization: UC Santa Cruz; Division of Social Sciences
Lines: 39

Is it possible to patch into HyperCard's window update / redraw
process and subsequently draw custom items on top of the card?

I have an XFCN that currently draws _temporary_ items on the screen;
the grafPort is conveniently set to HyperCard's window when my XFCN
gains control (I trust I can count on this always being the case?).
However, said XFCN erases anything it draws (via posting an invalidate
event or re-inverting objects drawn in XOR mode) before returning to
HyperCard, as things otherwise get messy when HyperCard starts doing
screen updates.

I know I could "domenu Paste" & copy my images onto the card graphic
or background layer of HyperCard, but I would rather leave these
layers undesturbed, as my objects could potentially move or go away,
& I wouldn't want the card or background graphics to be oblitterated
if this happened.  Also, things would get wierd if the user selected
a painting tool and blasted over my objects.

For the curious:  I have implemented transparant polygon buttons
for HyperCard, & would like to give the script-writer the option of
making them opaque or outlined if desired.  (The existing code
works quite well, however, and I will post it after I do a little
more work on it.)

On a related (but much more evil) note:  is it possible to add a new
menu _item_ (such as "New polybutton", perhaps...) under an existing
HyperCard menu (maybe "Objects"...)?  I don't want to add my own menu,
as some stacks might fill up all existing menu space with new menus
of their own.  Changes to the home stack should be transparant to stacks
that don't know about them.  I'm still trying to think of a good
method to use to get into the (as yet unwritten) polybutton editor;
creating my own HyperCard tool is obviously out of the question!  (Unless
I join the HyperCard development team and start working on v3.0. :>  ).

Any advice (other than "buy SuperCard"  :> ) would be appreciated.
  ___\    /___               Greg Anderson              ___\    /___ 
  \   \  /   /         Social Sciences Computing        \   \  /   /
   \  /\/\  /    University of California, Santa Cruz    \  /\/\  /
    \/    \/              sirkm@ssyx.ucsc.edu             \/    \/