
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{needspace}[2010/09/12 v1.3d reserve vertical space]

\newcommand{\needspace}[1]{%
  \begingroup
    \setlength{\dimen@}{#1}%
    \vskip\z@\@plus\dimen@
    \penalty -100\vskip\z@\@plus -\dimen@
    \vskip\dimen@
    \penalty 9999%
    \vskip -\dimen@
    \vskip\z@skip % hide the previous |\vskip| from |\addvspace|
  \endgroup
}

\newcommand{\Needspace}{\@ifstar{\@sneedsp@}{\@needsp@}}

\newcommand{\@sneedsp@}[1]{\par \penalty-100\begingroup
  \setlength{\dimen@}{#1}%
  \dimen@ii\pagegoal \advance\dimen@ii-\pagetotal
  \ifdim \dimen@>\dimen@ii
    \break
  \fi\endgroup}

\newcommand{\@needsp@}[1]{\par \penalty-100\begingroup
  \setlength{\dimen@}{#1}%
  \dimen@ii\pagegoal \advance\dimen@ii-\pagetotal
  \ifdim \dimen@>\dimen@ii
    \ifdim \dimen@ii>\z@
      \vfil
    \fi
    \break
  \fi\endgroup}

