\documentclass{article}

\usepackage[colorlinks=true]{hyperref}

\author{Guanyuming He\\ \url{https://github.com/guanyuming-he/onepgnote}}
\date{\today}
\title{Manual for onepgnote}

\begin{document}
\pagestyle{empty}
\maketitle
\tableofcontents

\clearpage
\section{Motivation}
The package was written when I was a student at Imperial College London,
preparing for an exam that allows each person to bring a one-page note.

As a \TeX nitian, I naturally wanted to typeset it using \LaTeX. At first, I
thought of using some existing package to do that. I found \texttt{cheatsheet}
on CTAN, but felt that I still could have saved a lot of space to put more
things on the paper. Moreover, I have a few cool ideas that \texttt{cheatsheet}
didn't provide. Thus, I made this package.

\section{Basic Ideas}
The package is designed to be simple yet powerful, thanks to the following
powerful ideas.
\begin{enumerate}
	\item One major space eater is the glues between sections. Yet they serve an
		important task: make the sectioning obvious. The first goal is to
		eliminate the space while keeping the sectionings very conspicuous. To
		accomplish that, I use \texttt{tcolorbox} with bright frames and
		\verb|\fbox|es.

		This feature overrides the \verb|\section| and \verb|\subsection|
		commands.
	\item A lot of ideas are put on a one-note page. Yet for spaces issues, one
		would want to write all related in a paragraph. Thus, I created macros
		for inline enumeration: each \verb|\item| is marked with an \verb|\tcbox|
		that is as small as about two letters, which contains the \verb|\item|
		number.

		This overrides the \verb|enumerate| environment.
	\item A lot of different ideas from all over the course are put in the note.
		As such, one would sometimes want to refer to another place in a note.
		Unfortunately, printed paper doesn't allow one to click on hyperlinks.
		
		Therefore, I made all \verb|\label|s and \verb|\ref|s visible, and each
		pair has a unique number to identify it.
	\item My major is math-heavy. I reduced the spaces before and after
		displayed math a lot.
	\item I use conspicuous inline \verb|\tcbox|es to also mark other important
		things. For example, if one wants to note something, then one puts a
		\verb|\notebox|, which produces a yellow inline box containing
		\texttt{NOTE}, followed by a space.
	\item It may seem a good idea to also load the \texttt{geometry} package to
		control the margins, etc. However, I believe it violates the modular
		principle. My package should not do things that it's not supposed to do. 

		Therefore, I avoided all such geometry manipulations in my package, so
		that a user can load such packages individually to configure what she
		wants.
\end{enumerate}

These few ideas don't take a lot lines of code to implement, but together, they
enable the making of very space-efficient and reading-efficient one-page notes.

\section{Usage}
The class is \verb!article!-based. You use it like a normal article except:
\begin{enumerate}
	\item I only override three sectioning commands: \verb|\section|,
	\verb|\subsection|, and \verb|\subsubsection|. Do not use the others.
	\item I only override listing environment \verb|enumerate|. Do not use the
		others. But I may override more in the future.
	\item Because of the tight space, you need to think of where you will allow
		additional breaks in inline math by \verb|\allowbreak|. I don't like to
		idea of using a global option to allow all breaks, so I leave the
		freedom to you.
\end{enumerate}

Please see the example mentioned in the next section to have a direct impression
on the effect. Also see its source code to notice that you indeed write the note
like using \verb|article|.

\section{Example (Template)}
Inside the package installation directory, you will notice an
\texttt{example.tex} that contains an example one-page note.

In fact, that was the note that I used for the exam I mentioned at the beginning
in the Motivation. I hope that demonstrates the simplicity and the power of my
package.

\section{Future directions}
As of version 1.0.0. All the features I want have been implemented and most of
them are configurable via class options.

One thing I could do in the future is to override more sectioning control
sequences and listing environments.

I could also add more styles of boxed, or add control sequences that allow the
user to easily create them, in the future.

\end{document}