Quebra automática de linha (não linha) em tabela (ou análogos) com um número variável de colunas

Question

Tenho alguns valores que preciso colocar no formato de linha maior, ou seja, preencher a coluna de uma tabela com base em sua largura, conforme descrito no MWE.

\documentclass[a4paper]{article}
\usepackage[margin=2cm]{geometry} % Just for this example
\setlength{\tabcolsep}{0.5cm}
\newcommand\myelement{\rule{1cm}{0.5cm}}
\begin{document}
Suppose each element width is 1 cm.

The whole page is 21 cm - 2*2 cm = 19 cm and therefore can contain
(19 cm / (1 cm + 2*0.5 cm)) = 9.5 = 9 elements, so the output should be like:

\begin{tabular}{rrrrrrrrr}
\myelement & \myelement & \myelement & \myelement & \myelement & \myelement & \myelement & \myelement & \myelement\\
\myelement & \myelement & \myelement & \myelement & \myelement & \myelement & \myelement & \myelement & \myelement\\
\myelement & \myelement & \myelement
\end{tabular}

~\\[1cm]

\begin{minipage}{0.5\linewidth}
Here the output should be like:

\begin{tabular}{rrrr}
\myelement & \myelement & \myelement & \myelement \\
\myelement & \myelement & \myelement & \myelement \\
\myelement & \myelement & \myelement & \myelement \\
\myelement & \myelement & \myelement & \myelement \\
\myelement & \myelement & \myelement & \myelement \\
\myelement
\end{tabular}
\end{minipage}
\end{document}

O número de colunas deve ser deduzido automaticamente da largura da caixa que contém o "ambiente/comando autocolumn" (nomeie como desejar), desde que a largura máxima dos elementos.

Qualquer ideia? Eu poderia usar LuaLaTeX, mas esta solução seria muito lenta e consumiria muita memória, então esta é a última opção.

Answer 1

\documentclass[a4paper]{article}
\usepackage[margin=2cm]{geometry} % Just for this example
\setlength{\tabcolsep}{0.5cm}
\newcommand\myelement{\rule{1cm}{0.5cm}}
\newcommand\xelement{\makebox[2cm]{\myelement}\hspace{0pt}}

\begin{document}
Suppose each element width is 1 cm.

The whole page is 21 cm - 2*2 cm = 19 cm and therefore can contain
(19 cm / (1 cm + 2*0.5 cm)) = 9.5 = 9 elements, so the output should be like:


\begin{flushleft}
\xelement  \xelement  \xelement  \xelement  \xelement  \xelement  \xelement  \xelement  \xelement
\xelement  \xelement  \xelement  \xelement  \xelement  \xelement  \xelement  \xelement  \xelement
\xelement  \xelement  \xelement
\end{flushleft}

\bigskip

\begin{minipage}{0.5\linewidth}
Here the output should be like:

\begin{flushleft}
\xelement  \xelement  \xelement  \xelement 
\xelement  \xelement  \xelement  \xelement 
\xelement  \xelement  \xelement  \xelement 
\xelement  \xelement  \xelement  \xelement 
\xelement  \xelement  \xelement  \xelement 
\xelement
\end{flushleft}
\end{minipage}
\end{document}