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From: shf@well.UUCP (Stuart H. Ferguson)
Newsgroups: comp.sys.amiga
Subject: Re: Clipboard support, and why it hasn't happened.
Message-ID: <14084@well.UUCP>
Date: 13 Oct 89 06:38:41 GMT
References: <8909250219.AA13930@jade.berkeley.edu> <899@madnix.UUCP> <4272@sugar.hackercorp.com> <156@ra.abo.fi>
Reply-To: shf@well.UUCP (Stuart H. Ferguson)
Organization: The Blue Planet
Lines: 62

+-- rosenber@ra.abo.fi (Robin Rosenberg INF) writes:
|  [ writing the clipboard is like an ordinary file ... ]
| Wha *IS* nasty is reading the thing. This is because one cannot know what is
| in the clip other than it is an IFF file.

I don't understand.  How does this make it *harder* than reading a file?
Files can be anything; at least you know the clipboard is IFF.

| The special case is a CAT with id 'CLIP' or id '    ', (the docs are ambigous
| on this).

The docs (RKM: Libraries and Devices) say specifically that this is a CAT
with identifier 'CLIP', not '    '.  Perhaps you were looking at the output
of a particular program...?

| This kind of clip is for representing alternative forms of the data,
| Lets say a spreatsheet supports the clipboard (Maxiplan does not, grrrrr...),
| If it's correct and the authors have understood the philosophy of the
| clipboard the would write a clipfile like this
| 
| 	CAT CLIP
| 	    FORMSPSH	- 'SPSH' -> spreadsheet data
| 		whatever format the spreadsheet preferes it's data in
| 	    FORMFTXT	- 'FTXT' -> Formattet text. Can be simple text
| 				    if there is no need for formatting it.
| 	    FORMILBM	- 'ILBM' -> Graphical representation (seems a little
| 				    superflous in this case.
| 
| Now switch to a word processor and select 'paste'. The program sees that the
| clip has alternative representations so it scans the clip for a representation
| it understands and processes it. The rest is skipped since it is other 
| representations of the same thing.

I quoted this whole example because it's exactly correct.  CAT CLIP is
designed to allow data to be cut and pasted between different applications
by letting the destination application find the kind of data it's interested
in among the different interpretations.  This can be a beautiful thing when
it's done right (or done at all, for that matter).  Let's say you have two
spreadsheets and a text document open at the same time.  You select some
interesting part of the spreadsheet and "Copy" it to the clipboard.  Now
you go to the other spreadsheet and "Paste" the data there.  You get all
the data and the formulas and formatting and everything that makes this
spreadsheet data.  Now -- WITHOUT DOING ANYTHING ELSE -- you paste the
SAME clip into the document.  Now you get the same data but in text form,
perhaps formatted into columns with tabs.  The formulas and everything
are gone, but this is exactly what you want for a document.

| > For 1.4. Pretty please?
| Simple routines for the simple cases and more advanced routines for the nasty
| ones. "Simple things should be simple and complex things should be possible"
| should be the rule.

Working on it.

| Another question: WIll there be a format for structured drawings in 1.4?

If you've got ideas, do it, but don't hold your breath waiting for
Commodore to define it.  Perhaps the "PLT:" people would like to
design such a thing.  Just don't make it HPGL-like, please.  :-)
-- 
		Stuart Ferguson		(shf@well.UUCP)
		Action by HAVOC		(ferguson@metaphor.com)