\tcbhypernode doesn't work in xetex

[muzimuzhi]

(originally reported and answered in https://www.zhihu.com/question/586573750/answer/2913873055, in Chinese)

\tcbhypernode{<macro>}{<node>} is expected to use <marco> to create a hyperlink having the same size of tikz node <node>. Currently in XeTeX such hyperlink is not created due to a XeTeX issue (actually I think the real culprit is xdvipdfmx).

As a workaround hyperref provides \XeTeXLinkBox{<link text>}, see texdoc hyperref, sec. 7.7 \XeTeXLinkBox and this answer by Heiko Oberdiek.

One possible patch:

% !TeX TS-program = xelatex
\documentclass{article}
\usepackage[skins]{tcolorbox}
\usepackage{hyperref}

\makeatletter
\renewcommand{\tcbhypernode}[2]{\ifdefined\hypersetup\@ifundefined{pgf@sh@ns@#2}{}{%
  \node[inner sep=0pt,outer sep=0pt] at (#2.center){%
    \tcbsetmacrotowidthofnode\tcb@w@hn{#2}%
    \tcbsetmacrotoheightofnode\tcb@h@hn{#2}%
    % debug: show size of hyperlink hence the need of altering \XeTeXLinkMargin
    % \hypersetup{pdfborder=0 0 0}%
    % change: wrap hyperlink text in \tcb@XeTeXLinkBox
    #1{\tcb@XeTeXLinkBox{\vtop to \dimexpr\tcb@h@hn-2bp\relax{\hbox to \dimexpr\tcb@w@hn-2bp\relax{}\vfil}}}%
  };%
}\fi}

\ifdefined\XeTeXversion
  \long\def\tcb@XeTeXLinkBox{%
    \setlength{\XeTeXLinkMargin}{0pt}%
    \XeTeXLinkBox}
\else
  \let\tcb@XeTeXLinkBox=\@firstofone
\fi
\makeatother

\begin{document}
%\tcbset{mybox/.style={enhanced, colback=#1!10, colframe=#1!50!black}}

\begin{tcolorbox}[enhanced,
  colback=red!10,colframe=red!50!black,
  hypertarget=hypertwinA,
  hyperlink=hypertwinB,
  title=Box A
]
  Click me to jump to Box B.
\end{tcolorbox}

\begin{tcolorbox}[enhanced,
  colback=blue!10,colframe=blue!50!black,
  hypertarget=hypertwinB,
  hyperlink=hypertwinA,
  title=Box B (with \texttt{\string\XeTeXLinkBox})
]
  Click me to jump to Box A.
\end{tcolorbox}

\makeatletter
\let\tcb@XeTeXLinkBox=\@firstofone
\makeatother

\begin{tcolorbox}[enhanced,
  colback=blue!10,colframe=blue!50!black,
  hypertarget=hypertwinB2,
  hyperlink=hypertwinA,
  title=Box B2 (without \texttt{\string\XeTeXLinkBox})
]
  Click me to jump to Box A.
\end{tcolorbox}

\newpage % make enough room for hyperlink scrolling/jumping
\null
\end{document}

Notes:

• Although hyperref provides \XeTeXLinkBox for all engines, I choose to only use it in XeTeX, to gain maximum backward compatibility for other engines.
• \XeTeXversion is used to test if it's in XeTeX. This is the same tester used by l3kernel in defining \c_sys_engine_str. Or if written in latex3 \sys_if_engine_xetex:TF can be used.

[T-F-S]

I will add this to the next version. Thank you!

[T-F-S]

Added to https://github.com/T-F-S/tcolorbox/releases/tag/v6.0.2