Adição

Question

Existe uma maneira de desenhar uma caixa simples com largura \textwidthe altura para que ela seja preenchida desde onde for colocada até a margem inferior da página?

Answer 1

Talvez eu ainda precise ajustar alguns parâmetros, mas aqui está uma ideia vertical \leadersque parece funcionar:

% My standard header for TeX.SX answers:
\documentclass[a4paper]{article} % To avoid confusion, let us explicitly 
                                 % declare the paper format.

\usepackage[T1]{fontenc}         % Not always necessary, but recommended.
% End of standard header.  What follows pertains to the problem at hand.

\usepackage{lipsum}

\makeatletter

\newcommand*\@helper@hboxto@hsize[2]{%
    \hb@xt@ \hsize {%
        \vrule \@width .4\p@ \@height #1\ht\strutbox \@depth #2\dp\strutbox
        \hfil
        \vrule \@width .4\p@ % automatic height and depth
    }
}
\newcommand*\@helper@hrule{%
    \kern -.2\p@
    \hrule \@height .2\p@ \@depth .2\p@
    \kern -.2\p@
}
\newcommand*\boxcolumnfill{%
    \par
    \vskip \dimexpr \dp\strutbox-\prevdepth
    \@helper@hrule
    \@helper@hboxto@hsize{.25}{.25}%
    \nobreak
    \xleaders \vbox {
                \kern -.25\ht\strutbox
                \@helper@hboxto@hsize{.5}{.5}%
                \kern -.25\dp\strutbox
            }\vfill
    \kern -.25\dp\strutbox
    \nointerlineskip
    \@helper@hboxto@hsize{.25}{0}%
    \@helper@hrule
    \break
}

\makeatother



\begin{document}

With some text before.
\lipsum*[1]
Is the positioning affected by the presence of descenders?
% Uncomment this line to find it out: Qfgjpqy.
\boxcolumnfill

\lipsum[2]

Whole pages of boxes follow.

\newpage
\boxcolumnfill
\boxcolumnfill

Some more text.

\end{document}

---

Adição

Aqui está outra versão do código, que fornece ao \boxcolumnfillcomando um argumento opcional, no qual você pode especificar uma quantidade de espaço em branco adicional a ser inserido acima da regra horizontal superior:

% My standard header for TeX.SX answers:
\documentclass[a4paper]{article} % To avoid confusion, let us explicitly 
                                 % declare the paper format.

\usepackage[T1]{fontenc}         % Not always necessary, but recommended.
% End of standard header.  What follows pertains to the problem at hand.

\usepackage{lipsum}

\makeatletter

\newcommand*\@helper@hboxto@hsize[2]{%
    \hb@xt@ \hsize {%
        \vrule \@width .4\p@ \@height #1\ht\strutbox \@depth #2\dp\strutbox
        \hfil
        \vrule \@width .4\p@ % automatic height and depth
    }
}
\newcommand*\@helper@hrule{%
    \kern -.2\p@
    \hrule \@height .2\p@ \@depth .2\p@
    \kern -.2\p@
}

% The user-level command; in the optional argument you can specify additional 
% whitespace to be inserted above the horizontal rule.
\newcommand*\boxcolumnfill[1][\z@]{%
    \par
    % Not yet sure: provide a legal breakpoint here, just in case the user 
    % passes an argument that is too tall?
    % \penalty \@highpenalty
    \kern \dimexpr \dp\strutbox-\prevdepth
                % The additional "\dimexpr" around "#1" is actually redundant 
                % here, but you know, Murphy's law...
                +\dimexpr #1\relax
            \relax
    \@helper@hrule
    \@helper@hboxto@hsize{.25}{.25}%
    \nobreak
    \xleaders \vbox {
                \kern -.25\ht\strutbox
                \@helper@hboxto@hsize{.5}{.5}%
                \kern -.25\dp\strutbox
            }\vfill
    \kern -.25\dp\strutbox
    \nointerlineskip
    \@helper@hboxto@hsize{.25}{0}%
    \@helper@hrule
    \break
}

\makeatother

\flushbottom % please note



\begin{document}

With some text before.
\lipsum*[1]
Is the positioning affected by the presence of descenders?
% Uncomment this line to find it out: Qfgjpqy.
\boxcolumnfill

\lipsum[2]

Some additional space above the rule,\\
without descenders.
% Now with descenders: Qfgjpqy.
\boxcolumnfill[\bigskipamount]

If used at the top of a new page, \verb|\boxcolumnfill| prints a box extending
to the full page height, but any additional space is ignored, even if specified.

\newpage
\boxcolumnfill
\boxcolumnfill[10cm]

This text should be on a new page.  Let's try it again:
\boxcolumnfill[10cm]

\lipsum[3-4]

Now, with an argument that is too tall for the available space:
\boxcolumnfill[15cm]

\textbf{Beware:} a negative argument \emph{is} honored!\\
without descenders.
% Now with descenders: Qfgjpqy.
\boxcolumnfill[-2\baselineskip]

Some more text.

\end{document}

Answer 2

Isso é fácil com tcolorboxo pacote. height fillopção cria caixas com altura igual ao espaço disponível até o final da página:

\documentclass[a4paper]{article} 
\usepackage[T1]{fontenc}         
\usepackage{lipsum}
\usepackage{lmodern}
\usepackage[most]{tcolorbox}

\begin{document}

With some text before.
\lipsum*[1]
\begin{tcolorbox}[height fill]
\end{tcolorbox}

\lipsum[2]
\begin{tcolorbox}[height fill]
\end{tcolorbox}

\begin{tcolorbox}[height fill]
\end{tcolorbox}

\lipsum[1-2]
\begin{tcolorbox}[height fill]
\end{tcolorbox}
\end{document}