How to make a bespoke itemize environment

Question

Sometimes in beamer I like to use itemize as follows (code largely from https://topanswers.xyz/tex?q=1334):

\documentclass{beamer}
\setbeamersize{text margin left=10mm,text margin right=5mm} 
\setbeamertemplate{frametitle}[default][center]
\newenvironment{grayenv}{\only{\setbeamercolor{local structure}{fg=black!15}}}{}
\begin{document}
\begin{frame}{Frame Title}
\setbeamertemplate{itemize items}[circle]
\addtolength{\leftmargini}{-0.7cm}
\begin{itemize}[<+-|gray@+(1)->]
\setlength\itemsep{5pt plus 1fill}
\item line one
\item line two
\item<+-> line three
\end{itemize}
\end{frame}
\end{document}

This has the effect of fading out bullet point markers for old bullet points as well as a few other features I find helpful. Notice that the final \item has to have <+-> so we don't get a new slide with all the markers gray.

Is there way to make a new environment myitemize that would capture all the features of my bespoke itemize environment?

Answer 1

You need to define the command \myitemize based on \itemize command and add your settings inside it and \endmyitemize command same as \enditemize

\documentclass{beamer}

\setbeamersize{text margin left=10mm,text margin right=5mm} 
\setbeamertemplate{frametitle}[default][center]
\newenvironment{grayenv}{\only{\setbeamercolor{local structure}{fg=black!15}}}{}
\setbeamertemplate{itemize items}[circle]

\addtolength{\leftmargini}{-0.7cm}

\newcommand{\myitemize}{\itemize[<+-|gray@+(1)->]
\setlength\itemsep{5pt plus 1fill}
\def\Item{\item<+->}
}
\let\endmyitemize\enditemize


\begin{document}
\begin{frame}{Frame Title}

\begin{myitemize}
\item line one
\item line two
\Item line three
\end{myitemize}

\end{frame}
\end{document}