[Tex/LaTex] Forming a “spoiler text” environment in LaTeX (via Javascript?)

javascript

I've been writing a mathematical text for some time, and seeing as it is the 21st century, I would like this text to be interactive and dynamic, probably in PDF format. The main function that I am looking to implement is a sort of "spoiler text" environment where the user can click a button to reveal content that is otherwise collapsed and unseen. This could be used to hide answers to exercises or proofs for theorems, etc.

I am led to believe that this is possible by using some form of Javascript embedded in LaTeX. Can somebody point me to a reference that would allow me to implement this, or better yet, explain to me how I should design this "spoiler text" environment?

Best Answer

Ok, this is an ugly hack, but if nothing else works, well, this will work. This is from The PracTEX Journal, 2006, No. 4, Article revision 2006/11/03, Hypertext capabilities with pdfTEX by Federico Garcia.

\pdfannot width w height h depth d { /Subtype /Text
/Contents (htexti)}

This is via pdfTEX primitives, so I have no idea what is going on with it. It makes a postit note in the document that you click on to see the text.

Instructions:

The three dimensions w, h, and d are all LATEX dimensions. But the one that is important is h (the height), because it determines where the note appears in relation to the text baseline. It is also a good idea use a \qquad after it.

Also note: This works fine in Adobe. It doesn't work at all in Sumatra PDF. Well, the note shows up, but you can't click it. So this is a bit risky (So is javascript for that matter, as a lot of PDF readers avoid it for security reasons).

A bit more from the article:

One thing to have in mind with post-it notes is that their exact behavior (color, size, when it opens, how it closes, etc.) is not very much standardized, and tends to change from version to version of Acrobat Reader. That said, the note can be of a different color if, between the brackets of \pdfannot, /C [r g b] is appended; a title for the note is determined with /T (title), and the note can show up open by default with /Open true.

Well, that is one way. A terrible, terrible way, but it would technically work.

Related Solutions

[Tex/LaTex] the best way to insert document-level JavaScript in LaTeX documents

A similar question was posted in the German newsgroup de.comp.text.tex recently.

With pdfLaTeX it is easy to add JavaScript at the document level. User defined JavaScript functions can be added as Action dictionaries (simple pdf objects) to the document. Then their names have to be mapped to the corresponding PDF object numbers in the /JavaScript name tree of the /Names dictionary in the PDF catalog using the pdfTeX primitive \pdfnames. Finally, the functions can be used within any PDF object that accepts an Action dictionary (links, widgets, pages, etc.). All this is documented in the PDF reference and in the JavaScript reference of Acrobat:

Here is a simple example which may serve as a starting point. Therein, doc-level JavaScript functions which accept arguments are used in the Action dictionaries of two links:

\documentclass{article}

\immediate\pdfobj{<<
  /S/JavaScript/JS (someFunc=function(arg){app.alert('I say ' + arg);})
>>}
\edef\someFunc{\the\pdflastobj\space 0 R}

\immediate\pdfobj{<<
  /S/JavaScript/JS (otherFunc=function(arg){app.alert('You say ' + arg);})
>>}
\edef\otherFunc{\the\pdflastobj\space 0 R}

\pdfnames{
  /JavaScript <<
    %name tree mapping doc. level JavaScript functions to object numbers
    /Names [(someFunc) \someFunc (otherFunc) \otherFunc ]
    /Limits [(otherFunc) (someFunc)] %first and last in alphab. order
  >>
}

\begin{document}
   \leavevmode
   \pdfstartlink user {
      /Subtype /Link
      /A <<
        /S/JavaScript
        /JS (someFunc('Hello!'))
      >>
   }Hello!\pdfendlink

   \leavevmode
   \pdfstartlink user {
      /Subtype /Link
      /A <<
        /S/JavaScript
        /JS (otherFunc('Good bye!'))
      >>
   }Good bye!\pdfendlink
\end{document}

Alexander

[Tex/LaTex] point-and-click open source javascript equation editor for latex

If you really want point and click functionality that builds up your latex code for you, try http://www.sciweavers.org/free-online-latex-equation-editor.

Alternatively, if you want to type in the source yourself and see if it compiles, try something like http://www.writelatex.com.

Best Answer

Related Solutions

[Tex/LaTex] the best way to insert document-level JavaScript in LaTeX documents

[Tex/LaTex] point-and-click open source javascript equation editor for latex

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