Re: [O] Beamer export with \only overlays - how?

[James Harkins]

Suvayu Ali <fatkasuvayu+linux <at> gmail.com> writes:

> Look a bit more carefully ;).  The following paragraph has an example
> suggesting the onlyenv environment.  As far as I understand,
> environments are prefered over commands with arguments or macros when
> translating headlines.  You can nest your block in such an environment.
> I realise this is a little less flexible than \only{}, but it seems to
> work.  I have not tried any of this personally in a long time though.

Indeed, this does the job. Thanks for the extra pointer.

For future readers, now I have this in my .emacs:

(add-to-list 'org-beamer-environments-extra
             '("onlyenv" "O" "\\begin{onlyenv}%a" "\\end{onlyenv}"))

And then I can export:

** Frame (beamer_act, not quite right)
*** The problem on this frame
    I want Block 1 and Block 2 to occupy the same space on successive 
slides.
*** OnlyEnv 1                                                     
:B_onlyenv:
    :PROPERTIES:
    :BEAMER_env: onlyenv
    :BEAMER_ACT: <1>
    :END:
**** Block 1
     Text
*** OnlyEnv 2                                                     
:B_onlyenv:
    :PROPERTIES:
    :BEAMER_env: onlyenv
    :BEAMER_ACT: <2>
    :END:
**** Block 2
     Text 2

-->

\begin{frame}[label=sec-1-1]{Frame (beamer$_{\text{act}}$, not quite right)}
\begin{block}{The problem on this frame}
I want Block 1 and Block 2 to occupy the same space on successive slides.
\end{block}

\begin{onlyenv}<1>
\begin{block}{Block 1}
Text
\end{block}
\end{onlyenv}

\begin{onlyenv}<2>
\begin{block}{Block 2}
Text 2
\end{block}
\end{onlyenv}
\end{frame}

~~~

I think I overlooked this in the manual because the overlay section is not 
organized around (what I think are) the most important user questions:

- Which overlays does org beamer export support?
- How to use them?

Instead, "onlyenv" appears in a paragraph whose topic sentence is "You can 
add your own environments by..." In other words, the information is "there," 
but organized in a way that would make your middle school English teacher 
break out the red pen.

I'll add a TODO for myself to rewrite this section. I don't know when I can 
get to it, though.

~~~

Why is onlyenv not supported out of the box?

hjh