Re: Patch for a new feature : sozi

[Hans Breuer <hans breuer org>]

At 31.07.2011 00:03, paul chavent fnac net wrote:
> I would like to submit you a patch for adding "Sozi" (http://sozi.baierouge.fr/wiki/en:welcome)
> to dia. This tool is a bit like Prezi.
This is certainly an interesting concept. The names sound a bit strange, 
though, see: http://de.wikipedia.org/wiki/Sozi ;)

> This patch adds a "Presentation" sheet, and a "Sozi frame" object. The frame allow to
> define the views of a presentation.
For a single object I think an own sheet is a bit overkill, at least I 
would have added it to the Misc sheet.

After trying your patch I think the frame sizing should be restricted to 
something which also can be reflected in the presentation. Possibly a 
rotateable rectangle as in the Inkscape tutorial [1] or a maybe a trapezoid 
if you want to support skewing.

The Sozi-Frame would be the first object actually modifying it's output 
dependent on the renderer. In prinziple I find this a bit suspicious 
conceptually, but maybe a dedicated export filter would indeed be less 
appropriate. Need to think about it.

Although the names Prezi and Sozi sound strange to me, I like them more 
than having the broad term 'Presentation' for this very specific concept.

> I made a tutorial draft for an overview of the creation process
> (http://paul.chavent.free.fr/sozi.html).
>
> My work is very basic, and is just a mockup.
>
> But before going further, i wonder if your team would like to see such a feature included in dia ?
It depends on the usability and maintainability. I'm a bit uncertain if 
Dia's own support for transformations isn't a bit too weak to make 
something really pretty.
Although my playing with your initial version and render-test.dia already 
looks promising (although lacking rotations ;-))

> If it would be the case, could you make a first code review for eliminating common pitfalls please ?
To be acceptable it has to compile with more than just gcc. These are the
two things which made trying out your patch a bit long-winded for me.

sozi-script.h(45) : error C2026: string too big, trailing characters truncated

  See: http://msdn.microsoft.com/en-us/library/dddywwsc%28v=vs.71%29.aspx

  But even if the compiler would have accepted it, IMO 16K of JavaScript
  on a single line is just not maintainable. Maybe the script should just
  stay an external file and be merged during serialization?

sozi-frame.c(321) : error C2065: '__PRETTY_FUNCTION__' : undeclared identifier

  Be careful with gcc specific extension. For the given one there is
  G_STRFUNC to make it portable.

For consistent rendering you have to set not only the line width, but also 
the style properties. Otherwise your Sozi frame's line style depends on the 
style of the previously drawn object. And that depends on the redraw
algorithm for interactive renderers.

For usability you should probably render some of the info of the 
Sozi-Frame, e.g. sequence number and frame timeout would be handy.

And maybe the frame rendering should be restricted to interactive renderers?

> Thank you for your reading.
Thanks for the patch, I'm looking forward to the next version ;-)

Regards,
        Hans

-------- Hans "at" Breuer "dot" Org -----------
Tell me what you need, and I'll tell you how to
get along without it.                -- Dilbert