[scribus-dev] Fwd: Great meeting you in Saarbrücken

[Tamir Hassan]

Hi Andreas,

On 6/11/19 8:20 AM, Andreas Vox wrote:
> I think it's only possible to achieve two of the following: editable, 
> stable layout and optimal layout. If you modify a document in another 
> application than the one which produced it, there will always be 
> difference in appearance, functionality or both.

I'm not quite sure what you mean by "optimal layout", but of course, I 
am trying to achieve the first two here. Opening a document for editing 
should not cause any reflow changes until the content has been edited, 
and then it should reflow in a predictable manner.

Optimal layout for me is not only the use of local and global 
optimization algorithms such as Knuth-Plass on the paragraph level, but 
also stuff such as pagination and figure placement on the global level. 
Combining this with interactive, WYSIWYG editing is a different problem, 
as everything would be jumping about from page to page every time a 
single character is typed, assuming the computation can be done fast 
enough. It would probably make the most sense to carry out global 
optimizations on demand once the content is known, and only locally 
optimize during editing (if at all.)

> But there's definitely a lot of opportunity to improve editing PDF if 
> you accept adequate layout changes. IMHO, reflow, font substitution, 
> change of color model, change of resolution and scaling are acceptable 
> layout changes. Missing content, inconsistent line breaking or 
> distortion are obviously not acceptable.

I wouldn't describe some of these as layout changes at all. But yes, if 
a font is substituted (PDF already provides mechanisms for this), this 
should not cause reflow and, in fact, if the font later becomes 
available again it should be substituted back.

> Layout programs like Scribus do not only use margins and columns, but 
> also have master/template pages, layers and text flowing around images. 
> Providing a standard for that will be much more challenging.

I understand. And ultimately we will have to draw the line somewhere. 
But I was under the impression that DTP has long been a mature 
technology and all the features that you mentioned here are also e.g. 
available in InDesign and other DTP applications (even if Inkscape 
doesn't support them all).

There would need to be a way for applications to store additional, 
app-specific metadata, but this should really only be used for special 
types of content, such as e.g. charts or diagrams, and even then, 
certain aspects, such as text formatting, should remain editable by 
other applications.

Best,
Tamir


-- 
Dr. Tamir Hassan
Round-Trip PDF Solutions
Research, development and consulting for the generation, analysis and 
data extraction from PDF documents

Zirkusgasse 31, 1020 Wien, Austria
www.roundtrippdf.com
tamir at tamirhassan.com
+43 676 721 6288