Vertically centered horizontal rule filling the rest of a line?

Question

I'd like to have a horizontal line extending from the end of the text on a line to the right margin. So far I've found \hrulefill and \leaders\hrule\hfill, but these draw a line that's flush with the baseline of my text — how can I get it to be vertically centered?

Answer 1

\documentclass{article}
\usepackage{xhfill}
\begin{document}
Here is some text\xfill{1pt} \par
Here is some text\xfill{8pt} \par
Here is some text\xhrulefill{blue}{2pt}\par
Here is some text\xhrulefill{cyan}{1ex}\par
Here is some text\xrfill[0ex]{1ex}[red] \par
\end{document}​

Answer 2

You can define a command similar to \hrulefill, but changing the height and depth of the rule used:

\documentclass{article}

\def\Vhrulefill{\leavevmode\leaders\hrule height 0.7ex depth \dimexpr0.4pt-0.7ex\hfill\kern0pt}

\begin{document}

\noindent text\hrulefill

\noindent text\Vhrulefill

\end{document}

Answer 3

\documentclass[a4paper]{article}

\newcommand\filltoend{\leavevmode{\unskip
  \leaders\hrule height.5ex depth\dimexpr-.5ex+0.4pt\hfill\hbox{}%
  \parfillskip=0pt\endgraf}}
\newenvironment{filllines}
  {\par\let\par\filltoend}
  {\par}

\usepackage{lipsum}

\begin{document}

A paragraph outside the environment can be ended with the
command \verb|\filltoend| like this one.\filltoend

\begin{filllines}
In this environment all paragraphs will be ended with a line.

As it's shown here.
\end{filllines}
\end{document}

The advantage of this approach with respect to the other proposed solutions is that it has no issues when the paragraph happens to end exactly at the right margin. However it won't work, for TeXnical reasons, with list environments inside filllines (list environments redefine \par in terms of the primitive commands, not taking into account its present meaning), but \filltoend will work.

If a rule is needed no matter what, change the specification

  \leaders\hrule height.5ex depth\dimexpr-.5ex+0.4pt\hfill

into

  \leaders\hrule height.5ex depth\dimexpr-.5ex+0.4pt\hskip1em plus 1fill

which will draw a rule at least 1em wide.

Answer 4

The following \centerline[<height>][<thickness>] produces a rule at height <height> (default is 0.5ex) and thickness <thickness> (default is 0.4pt). The horizontal alignment is not entirely optimal compared to a traditional \hrulefill, but this is perhaps not an issue.

\documentclass{article}
\usepackage{linegoal}% http://ctan.org/pkg/linegoal
\usepackage{xparse}% http://ctan.org/pkg/xparse
\NewDocumentCommand{\centerrule}{O{0.5ex} O{0.4pt}}{%
  \leavevmode\rule[#1]{\linegoal}{#2}}%
}
\begin{document}
Here is some text\centerrule \par
Here is some text\centerrule[0pt] \par
Here is some text\centerrule[0.5ex][1pt] \par
Here is some text\centerrule[0pt][2pt]
\end{document}​

The interface is provided by the xparse package, while the end-of-line estimation is done using \linegoal (from the linegoal package). It requires at least 2 compiles.