Creating environment that includes itemize and tcolorbox

Question

Consider the following MWE

\documentclass{article}
\usepackage{tikz,lipsum,lmodern}
\usepackage[most]{tcolorbox}
\usepackage{blindtext}

% https://tex.stackexchange.com/questions/350316/create-manual-page-break-within-tcolorbox
\newtcolorbox{ExampleBox}{%
    breakable,
    enhanced,
    colback=black!10!white,
    colframe=black!25!white,
    coltitle=black,
    title=\textbf{Example}
}
\newtcolorbox{NoteBox}{%
    breakable,
    enhanced,
    colback=red!10!white,
    colframe=red!25!white,
    coltitle=black,
    title=\textbf{Note}
}

\begin{document}


\begin{ExampleBox}
    \begin{itemize}
        \item Ich gehe nach Hause. \textit{I'm going home.}\\ 
        \blindtext[1]
        \item Ich gehe nach Hause. \textit{I'm going home.}
    \end{itemize} 
\end{ExampleBox}
\begin{NoteBox}
    \begin{itemize}
        \item Ich gehe nach Hause. \textit{I'm going home.}\\ 
        \blindtext[1]
    \end{itemize} 
\end{NoteBox}

\end{document}

This creates two new tcolorboxes named ExampleBox and NoteBox. Now in my original document I have several more of these boxes and their content is always of the same form: an itemize environment, where each \item is followed by some text, then some cursive text and then an optional \\ + some more text.

This approach gives me the desired result but involves a lot of (hopefully) unnecessary writing. So I was wondering if it is possible to create an environment of the form

\begin{environment}[ex]
    \item{first sentence}{cursive sentence}{optional text}
    \item{first sentence}{cursive sentence}
\end{environment}

which should produce the same result as the above ExampleBox. The idea would be to define somewhere (in some form) triplets of the form (tag, Title, color) --- which would be in the above case (ex, Example, black) --- to make the generation and using of such very specific tcolorboxes a bit easier.

---

Not sure if relevant, but I use LuaLaTeX and the first sentence in the modified \item environment would contain special characters (like Kanji or Cyrillic letters).

Answer 1

Here is my attempt. The color and title of the box are automatically determined depending on the argument gien to the new MyItemBox environment. Please note that I did not include a third optional argument to the custom \item-like command.

\documentclass{article}
\usepackage[most]{tcolorbox}
\usepackage{blindtext}

\usepackage{xstring}     % Used for \IfEqCase


\newcommand{\myboxtitle}{default}     % Default box title
\definecolor{myboxcolor}{named}{blue} % Default box color
\newtcolorbox{MyBox}[1]{%
    breakable,
    enhanced,
    colback=myboxcolor!10!white,      % Box color is used here
    colframe=myboxcolor!25!white,     % Box color is used here
    coltitle=black,
    title=\textbf{\myboxtitle}        % Box title is used here 
}

\newenvironment{MyItemBox}[1]{\IfEqCase{#1}{%                                % Code at the beginning of the environment
                             {ex}{\definecolor{myboxcolor}{named}{black}%    % Define color and title for argument = ex
                                  \renewcommand{\myboxtitle}{Example}}%
                             {note}{\definecolor{myboxcolor}{named}{red}%    % Define color and title for argument = note
                                    \renewcommand{\myboxtitle}{Note}}%
                             }\begin{MyBox}{#1}%
                             \begin{itemize}}%
                             {\end{itemize}%                                 % Code at the ned of the environment
                              \end{MyBox}}

\newcommand{\myitem}[2]{\item #1 \textit{#2}}      % Custom itemize command. Second argument is italics



\begin{document}

\begin{MyItemBox}{note}
\myitem{Ich gehe nach Hause.}{I'm going home.}\\ 
\blindtext[1]
\myitem{Ich gehe nach Hause.}{I'm going home.}
\end{MyItemBox}

\begin{MyItemBox}{ex}
\myitem{Ich gehe nach Hause.}{I'm going home.}
\myitem{Ich gehe nach Hause.}{I'm going home.}
\end{MyItemBox}

\begin{MyItemBox}{}
\myitem{Ich gehe nach Hause.}{I'm going home.}
\myitem{Ich gehe nach Hause.}{I'm going home.}
\end{MyItemBox}



\end{document}

Answer 2

A proposition of \myitem command, based on the xparse package. The \IfValueT{#3}{\\ #3} checks if an optional text is given or not.

\documentclass{article}
\usepackage{tikz,lipsum,lmodern}
\usepackage[most]{tcolorbox}
\usepackage{blindtext}
\usepackage{xparse}

% https://tex.stackexchange.com/questions/350316/create-manual-page-break-within-tcolorbox
\newtcolorbox{ExampleBox}{%
    breakable,
    enhanced,
    colback=black!10!white,
    colframe=black!25!white,
    coltitle=black,
    title=\textbf{Example}
}
\newtcolorbox{NoteBox}{%
    breakable,
    enhanced,
    colback=red!10!white,
    colframe=red!25!white,
    coltitle=black,
    title=\textbf{Note}
}

\NewDocumentCommand{\myitem}{ m m o }{
\item #1 \textit{#2} \IfValueT{#3}{\\ #3}
}
% New command with 2 mandatory and one optional arguments
% With a value check on optional argument

\begin{document}


\begin{ExampleBox}
    \begin{itemize}
        \myitem{Ich gehe nach Hause.}{I'm going home.}[\blindtext[1]]
         \myitem{Ich gehe nach Hause.}{I'm going home.}
    \end{itemize} 
\end{ExampleBox}
\begin{NoteBox}
    \begin{itemize}
        \myitem{Ich gehe nach Hause.}{I'm going home.}[\blindtext[1]]
    \end{itemize} 
\end{NoteBox}

\end{document}

EDIT Slight variant taking advantage of tcolorbox's skins library

\documentclass{article}
\usepackage{tikz,lipsum,lmodern}
\usepackage[most]{tcolorbox}
\tcbuselibrary{skins}
\usepackage{blindtext}
\usepackage{xparse}

\newenvironment{ExampleBox}{\begin{itemize}}{\end{itemize}}
\tcolorboxenvironment{ExampleBox}{%
    breakable,
    enhanced,
    colback=black!10!white,
    colframe=black!25!white,
    coltitle=black,
    title=\textbf{Example}
}
\newenvironment{NoteBox}{\begin{itemize}}{\end{itemize}}
\tcolorboxenvironment{NoteBox}{%
    breakable,
    enhanced,
    colback=red!10!white,
    colframe=red!25!white,
    coltitle=black,
    title=\textbf{Note}
}

\NewDocumentCommand{\myitem}{ m m o }{
\item #1 \textit{#2} \IfValueT{#3}{\\ #3}
}
% New command with 2 mandatory and one optional arguments
% With a value check on optional argument

\begin{document}
\begin{ExampleBox}
        \myitem{Ich gehe nach Hause.}{I'm going home.}[\blindtext[1]]
         \myitem{Ich gehe nach Hause.}{I'm going home.}
\end{ExampleBox}
\begin{NoteBox}
        \myitem{Ich gehe nach Hause.}{I'm going home.}[\blindtext[1]]
\end{NoteBox}
\end{document}