如何防止空参数的垂直空间

Question

这是我之前（也许不必要地复杂）的问题的更新版本：

\documentclass[10pt]{article}
\usepackage[english]{babel}
\usepackage[paperwidth=6in,paperheight=9in, margin=1in]{geometry}
\usepackage{libertine}
\usepackage[T1]{fontenc}
\usepackage[latin9]{inputenc}

\newenvironment{customminipage}
  {\begin{minipage}[t]{3in}}
  {\end{minipage}\par\addvspace{6ex}\ignorespacesafterend}

\newcommand{\mynewcommand}[3]{
{\begin{customminipage}#1\end{customminipage}}
{\begin{customminipage}#2\end{customminipage}}
{\begin{customminipage}#3\end{customminipage}}
}

\begin{document}
Some text

\mynewcommand
{}
{}
{Argument 3}

Some text
\end{document}

生成：

我应该怎么做（也许minipage方法不是最佳方法）来防止空参数的垂直间距？

Answer 1

在使用强力环境之前，请先使用\notblank{#1}{true branch}{false branch}frometoolbox测试空参数，minipage无论是否要插入某些文本，都会添加垂直空间。

\documentclass[10pt]{article}
\usepackage[english]{babel}
\usepackage[paperwidth=6in,paperheight=9in, margin=1in]{geometry}
\usepackage{libertine}
\usepackage[T1]{fontenc}
\usepackage{etoolbox}
\usepackage[latin9]{inputenc}

\newenvironment{customminipage}
{\begin{minipage}[t]{3in}}
  {\end{minipage}\par\addvspace{6ex}\ignorespacesafterend}

\newcommand{\mynewcommand}[3]{%
  \notblank{#1}{\begin{customminipage}#1\end{customminipage}}{}%
  \notblank{#2}{\begin{customminipage}#2\end{customminipage}}{}%
  \notblank{#3}{\begin{customminipage}#3\end{customminipage}}{}%
}

\begin{document}
Some text

\mynewcommand
{}
{}
{Argument 3}

\mynewcommand
{And now}
{for something completely different}
{Argument 3}


Some text
\end{document}