LuaTeX colored boxes with rounded corners

Question

What is the simplest way to make coloured boxes with rounded corners in luatex? With xelatex I used pstricks and it was simple, but with luatex it is not working.

Answer 1

The simplest method is to use the mdframed or the tcolorbox package (example for tcolorbox: http://ctan.org/tex-archive/macros/latex/contrib/tcolorbox) package, which use TikZ. You can integrate with Lua as per the following MWE example, which uses both packages. It also runs the code and typesets the example. Please ensure you have the latest versions for all and run as LuaLaTeX (tcolorbox was updated recently).

I have used the same base code from another post of mine How can I produce vertical white space in a table with LuaLaTeX?, which I posted tonight. Have a look also at that post for unframed boxes (they look better to me).

\documentclass{book}
\usepackage[listings]{tcolorbox}
\lstloadlanguages{[LaTeX]TeX, [primitive]TeX,Pascal}
\usepackage{filecontents}
\usepackage[framemethod=TikZ]{mdframed}
\usepackage{amsmath}
\usepackage{luacode} % loads luatexbase as well
\newcommand\emphasis[2][blue]{\lstset{emph={exec,if,then,else,do,end,while,for,print,sprint,directlua,#2},
   emphstyle={\ttfamily\textcolor{#1}}}}%
\lstset{language={[LaTeX]TeX},
      stepnumber=1,numbersep=5pt, 
      numberstyle={\footnotesize\color{gray}},%firstnumber=last,
      breaklines=true,
      framesep=5pt,
      basicstyle=\small\ttfamily,
      showstringspaces=false,
      keywordstyle=\ttfamily\textcolor{blue},
      stringstyle=\color{orange},
      commentstyle=\color{black},
      rulecolor=\color{gray!10},
      breakatwhitespace=true,
      showspaces=false,  % shows spacing symbol
      backgroundcolor=\color{gray!15}}

\makeatother
\begin{document}

\emphasis{return,repeat,until,function,local}
\begin{tcblisting}{}
\begin{luacode}
-- example adapted from
-- http://rosettacode.org/wiki/Happy_numbers
function boxit(color, var, s)
 zz="\\mdframed[roundcorner=3pt, leftmargin=2cm,innertopmargin=0pt,innerbottommargin=0pt, innerleftmargin=0pt,innerrightmargin=0pt, innerlinewidth=0pt, middlelinewidth=0pt,outerlinewidth=1pt, outerlinecolor=red]"..var.."\\endmdframed"
 return zz
end
function digits(n)
  if n > 0 then return n \% 10, digits(math.floor(n/10)) end
end
function sumsq(a, ...)
  return a and a ^ 2 + sumsq(...) or 0
end
local happy = setmetatable({true, false, false, false}, {
      __index = function(self, n)
         self[n] = self[sumsq(digits(n))]
         return self[n]
      end } )
i, j = 0, 8
repeat
   i, j = happy[j] and (tex.sprint(boxit(violet, j, " ")) or i+1) or i, j + 1
until i == 17 --or j > 999
\end{luacode}
\end{tcblisting}
\end{document}