[NTG-context] presentations: "page number" and "next page"

[Mojca Miklavec]

Hello,

Shortly:

I would like modify the meaning of "previous/next page" buttons in 
interaction menu to point to the previous/next slide instead on the 
previous/next physical page. And I would like to number pages according 
to slides instead of considering physical pages.

***********************************************************************

And here's a more detailed description:

I use the "rsteps" module (by David Munger) for my presentation.

I also use the interaction menu:

\startinteractionmenu[bottom]
...
   \but [nextpage]                \symbol[nextpage]       \\
   \but [lastpage]                \symbol[lastpage]       \\
...
   \but [CloseDocument]           \symbol[CloseDocument]  \\
\stopinteractionmenu

Instead of
   \but [previouspage]            \symbol[previouspage]   \\
   \but [nextpage]                \symbol[nextpage]       \\
pointing on the previous and next slide, I would like these two buttons 
to have slightly different functionality: pointing to the LAST step of 
the previous/next slide.

Apart from that, I would like to keep the page number on different steps 
of the same slide. I would use this number to print it in footer and to 
call it from Metafun (PageNumber, NOfPages or a similar name, as in 
meta-ini.tex).

Here's the idea of how the presentation should look like. In the table 
below there's a:
- real page number (in pdf document),
- slide number (= same content gradually growing),
- step on slide,
- page number as it should be printed in footer and made accessible to 
metapost if needed,
- real page number where the "Previous" button should point to,
- real page number where the "Next" button should point to


1 - titlepage

2 - slide 1, step 1 - page 1 - < [titlepage] > 3
3 - slide 1, step 2 - page 1 - < [titlepage] > 6

4 - slide 2, step 1 - page 2 - < 3 > 6
5 - slide 2, step 2 - page 2 - < 3 > 6
6 - slide 2, step 3 - page 2 - < 3 > 7

7 - slide 3, step 1 - page 3 - < 6 > 10

8 - slide 4, step 1 - page 4 - < 7 > 10
9 - slide 4, step 2 - page 4 - < 7 > 10
0 - slide 4, step 3 - page 4 - < 7 > [none/self]



I'm interested in the result on the first place, not so much on the 
mechanism that would "automatically recognize a new page and place 
everything as desired", so I don't mind if I have to (type)set anything 
manually. For example, it is no problem if I have to say

\StartSteps[title]
\thisIsANewSlideSoPlaceANewPageNumberInFooterAndLetMetafunKnowIfSheAsksForIt
...
\OnlyStep[3]{\thePrevAndNextButtonsHaveToStopOnThisPage}
...
\StopSteps

Thank you very much for your help,
	Mojca Miklavec