+% This \urefbreak definition is the active one.
+\def\urefbreak{\begingroup \urefcatcodes \dourefbreak}
+\let\uref=\urefbreak
+\def\dourefbreak#1{\urefbreakfinish #1,,,\finish}
+\def\urefbreakfinish#1,#2,#3,#4\finish{% doesn't work in @example
+ \unsepspaces
+ \pdfurl{#1}%
+ \setbox0 = \hbox{\ignorespaces #3}%
+ \ifdim\wd0 > 0pt
+ \unhbox0 % third arg given, show only that
+ \else
+ \setbox0 = \hbox{\ignorespaces #2}%
+ \ifdim\wd0 > 0pt
+ \ifpdf
+ \unhbox0 % PDF: 2nd arg given, show only it
+ \else
+ \unhbox0\ (\urefcode{#1})% DVI: 2nd arg given, show both it and url
+ \fi
+ \else
+ \urefcode{#1}% only url given, so show it
+ \fi
+ \fi
+ \endlink
+\endgroup}
+
+% Allow line breaks around only a few characters (only).
+\def\urefcatcodes{%
+ \catcode\ampChar=\active \catcode\dotChar=\active
+ \catcode\hashChar=\active \catcode\questChar=\active
+ \catcode\slashChar=\active
+}
+{
+ \urefcatcodes
+ %
+ \global\def\urefcode{\begingroup
+ \setupmarkupstyle{code}%
+ \urefcatcodes
+ \let&\urefcodeamp
+ \let.\urefcodedot
+ \let#\urefcodehash
+ \let?\urefcodequest
+ \let/\urefcodeslash
+ \codex
+ }
+ %
+ % By default, they are just regular characters.
+ \global\def&{\normalamp}
+ \global\def.{\normaldot}
+ \global\def#{\normalhash}
+ \global\def?{\normalquest}
+ \global\def/{\normalslash}
+}
+
+% we put a little stretch before and after the breakable chars, to help
+% line breaking of long url's. The unequal skips make look better in
+% cmtt at least, especially for dots.
+\def\urefprestretch{\urefprebreak \hskip0pt plus.13em }
+\def\urefpoststretch{\urefpostbreak \hskip0pt plus.1em }
+%
+\def\urefcodeamp{\urefprestretch \&\urefpoststretch}
+\def\urefcodedot{\urefprestretch .\urefpoststretch}
+\def\urefcodehash{\urefprestretch \#\urefpoststretch}
+\def\urefcodequest{\urefprestretch ?\urefpoststretch}
+\def\urefcodeslash{\futurelet\next\urefcodeslashfinish}
+{
+ \catcode`\/=\active
+ \global\def\urefcodeslashfinish{%
+ \urefprestretch \slashChar
+ % Allow line break only after the final / in a sequence of
+ % slashes, to avoid line break between the slashes in http://.
+ \ifx\next/\else \urefpoststretch \fi
+ }
+}
+
+% One more complication: by default we'll break after the special
+% characters, but some people like to break before the special chars, so
+% allow that. Also allow no breaking at all, for manual control.
+%
+\parseargdef\urefbreakstyle{%
+ \def\txiarg{#1}%
+ \ifx\txiarg\wordnone
+ \def\urefprebreak{\nobreak}\def\urefpostbreak{\nobreak}
+ \else\ifx\txiarg\wordbefore
+ \def\urefprebreak{\allowbreak}\def\urefpostbreak{\nobreak}
+ \else\ifx\txiarg\wordafter
+ \def\urefprebreak{\nobreak}\def\urefpostbreak{\allowbreak}
+ \else
+ \errhelp = \EMsimple
+ \errmessage{Unknown @urefbreakstyle setting `\txiarg'}%
+ \fi\fi\fi
+}
+\def\wordafter{after}
+\def\wordbefore{before}
+\def\wordnone{none}
+
+\urefbreakstyle after
+