[pdftex] pdf objects with references to each other?

Hans Hagen pragma at wxs.nl
Mon Apr 1 00:57:50 CEST 2002


At 03:36 PM 3/31/2002 +1000, Robert Howlett wrote:
>Hans Hagen wrote:
> >
> > What exactly is wrong with the optimization that acrobat applies? I tested
> > it on my own implementation of notes (comments) and it came out as
> > expected. (just curious)
> >
> > Hans
> >
>
>There were a couple of things that surprised me about comments
>when I started looking at my pdf files with the full Acrobat
>rather than just the reader. I noticed that my text notes were
>not the shape that I had specified, and that the title bar of
>the note included a date. Also when I right click the comment
>and choose "properties" I find that what I thought was the title
>of the note Acrobat thinks is the author. I couldn't understand
>why Acrobat was changing the appearance of my notes like this,
>until I eventually discovered that what Acrobat was showing me was
>not my own note but a popup of its own creation. And as soon as
>I optimize the file that popup gets included and clobbers my
>text note for everyone whether they are using the full Acrobat
>or just the reader.

strange indeed (although i only observe the lost dimensions, not the 
title); i consider this an acrobat bug since it violates upward compatibility

btw, this is not so much related to optimization as well to in mem 
generation of appearance streams which happens with more constructs, like 
forms, i think that the split in two annot is a kind of side effect (sort 
of expanding objects in mem, then generating appearance stream)

it's also worth noting that dimensions are kind of scaled / related to page 
dimensions so specifying text annot sizes does not give you what you expect.

>I contemplated going back to Acrobat 3, which I used to use
>for optimizing my pdf files, or starting to use ghostscript
>for the purpose. But one of the main reasons I got Acrobat 5
>was to use it to optimize pdf files; so I was pleased to discover
>that I could frustrate it by making the popup myself before
>it got the chance.

your observation is right, actually one of the downsides of pdftex is that 
it can do things that other tools cannot do, which means that a change in 
acrobats internals will affect (and be noticed) only in pdftex generated 
files; (another example is a javascript resource tree: possible conforming 
pdf 1.3, but viewers failed on it, so i reverted to teh non tree approach; 
something similar happended when pdftex version 'long ago' built a page 
tree according to the specs: didn't work, so thanh had to change it.

Hans
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