ch2_text_format.tex

\chapter{Formatting of Text and Paragraphs}

\paragraph{Introduction}
This chapter describes how to adjust the various aspects of text, such as fonts, size/shapes/styles, and positioning.

\section{About Fonts}

\subsection{The Three Font Families}

\paragraph{(Sans) Serif, Typewriter}
In any \LaTeX{} document, the text can be typed in three different \textit{font families}\index{Font Family}: \textit{serif}\index{Serif}, \textit{sans serif}\index{Sans Serif}, and \textit{typewriter}\index{Typewriter}. In this book, headings (of chapters, sections, etc.) are in the sans serif family by default, while the remaining main text is in serif. Table \ref{tab:fontfamily} below demonstrates how to select a specific font family for a piece of text.

\begin{table}[ht!]
\begin{tabularx}{\textwidth}{|l|X|l|l|}
\hline
Font Family & Command & Switch & Output \\
\hline
Serif & \texttt{\textbackslash textrm\{Hello World!\}}& \texttt{\textbackslash rmfamily} & \textrm{Hello World!} \\
\hline
Sans Serif & \texttt{\textbackslash textsf\{Hello World!\}}& \texttt{\textbackslash sffamily} & \textsf{Hello World!} \\
\hline
Typewriter & \texttt{\textbackslash texttt\{Hello World!\}}& \texttt{\textbackslash ttfamily} & \texttt{Hello World!} \\
\hline
\end{tabularx}
\caption{The commands for switching between the three font families and what they look like.}
\label{tab:fontfamily}
\end{table}%
\index{textrm@\texttt{\textbackslash textrm}}\index{textsf@\texttt{\textbackslash textsf}}\index{texttt@\texttt{\textbackslash texttt}}\index{rmfamily@\texttt{\textbackslash rmfamily}}\index{sffamily@\texttt{\textbackslash sffamily}}\index{ttfamily@\texttt{\textbackslash ttfamily}}%
For instance, both
\begin{lstlisting}
produces the following output: \par
\textsf{\lipsum[3]} % or {\sffamily \lipsum[3]}, curly brackets {} are to limit the scope of the \sffamily command.
\end{lstlisting}
produces the following output: \par
{\sffamily \lipsum[3]}

\subsection{Changing the Actual Font for a Font Family}

\paragraph{Font Libraries}
Each of the previous font families is internally assigned a specific \textit{font}\index{Font}. To change the actual font, we can import the corresponding font package. The \textbf{\LaTeX{} Font Catalogue}\index{LaTeX Font Catalogue@\LaTeX{} Font Catalogue} (\href{https://tug.org/FontCatalogue/}{https://tug.org/FontCatalogue/}) provides a comprehensive list of available fonts and the way to load them. This book has substituted the Noto Sans font for the sans serif family via the preamble
\begin{lstlisting}
\usepackage[T1]{fontenc}
\usepackage[sf]{noto}
\end{lstlisting}

\begin{exercisebox}
\begin{Exercise}
\label{exer:font}%
Change the font family just for the dummy Lipsum paragraph above to typewriter.
\end{Exercise}
\begin{Exercise}
Choose a font of your liking from the Font Catalogue to replace the original one in the book.
\end{Exercise}
\end{exercisebox}
\setboolean{firstanswerofthechapter}{true}%
\begin{Answer}[ref=exer:font]
\begin{lstlisting}
\texttt{\lipsum[3]} % or {\ttfamily \lipsum[3]}
\end{lstlisting}
\end{Answer}
\setboolean{firstanswerofthechapter}{false}

\section{Text Attributes}

\subsection{Font Size}

\paragraph{Size Commands}
In Section \ref{sec:komaopt}, we talked about setting the base global font size by \texttt{\textbackslash KOMAoptions}. However, to control the \textit{local font size}\index{Font Size} for some places, we can use the \textit{size commands}\index{Size Command}, listed in Table \ref{tab:fontsize} below.

\begin{table}[ht!]
\begin{captionbeside}[test]{The various commands for controlling font size in text.\footnotemark}[l][\textwidth]{
\adjustbox{valign=t}{\begin{tabularx}{0.6\textwidth}{|>{\rule{0pt}{20pt}}l|X|}
\hline
Command & Output \\
\hline
\texttt{\textbackslash tiny} & {\tiny Who am I?} \\
\hline
\texttt{\textbackslash scriptsize} & {\scriptsize Who am I?} \\
\hline
\texttt{\textbackslash footnotesize} & {\footnotesize Who am I?} \\
\hline
\texttt{\textbackslash small} & {\small Who am I?} \\
\hline
\texttt{\textbackslash normalsize} & {\normalsize Who am I?} \\
\hline
\texttt{\textbackslash large} & {\large Who am I?} \\
\hline
\texttt{\textbackslash Large} & {\Large Who am I?} \\
\hline
\texttt{\textbackslash LARGE} & {\LARGE Who am I?} \\
\hline
\texttt{\textbackslash huge} & {\huge Who am I?} \\
\hline
\texttt{\textbackslash Huge} & {\Huge Who am I?} \\
\hline
\end{tabularx}}}
\end{captionbeside}
\label{tab:fontsize}
\end{table}%
\index{tiny@\texttt{\textbackslash tiny}}\index{scriptsize@\texttt{\textbackslash scriptsize}}\index{footnotesize@\texttt{\textbackslash footnotesize}}\index{small@\texttt{\textbackslash small}}\index{normalsize@\texttt{\textbackslash normalsize}}\index{large@\texttt{\textbackslash large}}\index{Large@\texttt{\textbackslash Large}}\index{LARGE@\texttt{\textbackslash LARGE}}\index{huge@\texttt{\textbackslash huge}}\index{Huge@\texttt{\textbackslash Huge}}%
For example, writing
\begin{lstlisting}
produces \par
{\small Though she be but little} {\LARGE she is fierce} \\ % scope
\scriptsize % switch
taken from Shakespeare's A Midsummer Night's Dream
\normalsize % back to default ...
\end{lstlisting}
produces \par
{\small Though she be but little} {\LARGE she is fierce} \\
\scriptsize
taken from Shakespeare's A Midsummer Night's Dream
\normalsize \par
The double backslash \texttt{\textbackslash \textbackslash}\index{\texttt{\textbackslash \textbackslash}} sign breaks the current line and starts a new line right below. And again, the curly brackets \verb|{}|\index{\texttt{\{\}}} limit the effect of commands within their scope.

\paragraph{Fixing Font Size}
\footnotetext{\texttt{\textbackslash huge} and \texttt{\textbackslash Huge} have the same size when the font size is 12 pt (but different for 10 or 11 pt).}
It is also possible to fix a numerical value for the font size using \texttt{\textbackslash fontsize\{<font\_size>\}\{<line\_spacing>\}}\index{fontsize@\texttt{\textbackslash fontsize}} and \texttt{\textbackslash selectfont}\index{selectfont@\texttt{\textbackslash selectfont}}. As an illustration, the code
\begin{lstlisting}
leads to \par
{\fontsize{15pt}{21pt}\selectfont May those who accept their fate be granted happiness. May those who defy their fate be granted glory. \\ -- Princess Tutu \par} % \par is needed for update the parameters
\end{lstlisting}
leads to \par
\begin{samepage}
\fontsize{15pt}{21pt}\selectfont May those who accept their fate be granted happiness. May those who defy their fate be granted glory. \\
-- Princess Tutu \par
\end{samepage}

\subsection{Font Shapes}

\paragraph{Italic, Bold, and More}
Similar to font families, there are different \textit{font shapes}/\allowbreak\textit{styles}\index{Font Shape/Style} such as the commonly seen \textit{italic}\index{Italic} or \textit{bold}\index{Bold}. Table \ref{tab:fontshape} above shows the relevant commands to invoke them.

\begin{table}[ht!]
\begin{tabularx}{\textwidth}{|l|X|l|l|}
\hline
Font Style & Command & Switch & Output \\
\hline
Bold & \texttt{\textbackslash textbf\{"10 Downing"\}}& \texttt{\textbackslash bfseries} & \textbf{"10 Downing"} \\
\hline
Medium & \texttt{\textbackslash textmd\{"10 Downing"\}}& \texttt{\textbackslash mdseries} & \textmd{"10 Downing"} \\
\hline
Italic & \texttt{\textbackslash textit\{"10 Downing"\}}& \texttt{\textbackslash itshape} & \textit{"10 Downing"} \\
\hline
Slanted & \texttt{\textbackslash textsl\{"10 Downing"\}}& \texttt{\textbackslash slshape} & \textsl{"10 Downing"} \\
\hline
Small Caps & \texttt{\textbackslash textsc\{"10 Downing"\}}& \texttt{\textbackslash scshape} & \textsc{"10 Downing"} \\
\hline
Upright & \texttt{\textbackslash textup\{"10 Downing"\}}& \texttt{\textbackslash upshape} & \textup{"10 Downing"} \\
\hline
\end{tabularx}
\caption{The commands for different font styles. The medium/upright style is effectively the default normal.}
\label{tab:fontshape}
\end{table}%
\index{textbf@\texttt{\textbackslash textbf}}\index{textmd@\texttt{\textbackslash textmd}}\index{textit@\texttt{\textbackslash textit}}\index{textsl@\texttt{\textbackslash textsl}}\index{textsc@\texttt{\textbackslash textsc}}\index{textup@\texttt{\textbackslash textup}}\index{bfseries@\texttt{\textbackslash bfseries}}\index{mdseries@\texttt{\textbackslash mdseries}}\index{itshape@\texttt{\textbackslash itshape}}
\index{slshape@\texttt{\textbackslash slshape}}
\index{scshape@\texttt{\textbackslash scshape}}
\index{upshape@\texttt{\textbackslash upshape}}%
Adding to the previous example, we can write
\begin{lstlisting}
which produces \par
\textit{\small Though she be but little} {\LARGE \bfseries \scshape she is fierce} \\ % scope
\scriptsize % switch
taken from \slshape \underline{Shakespeare's A Midsummer Night's Dream}
\normalsize \upshape \par % back to default
...
\end{lstlisting}
which produces \par
\textit{\small Though she be but little} {\LARGE \bfseries \scshape she is fierce} \\
\scriptsize
taken from \slshape \underline{Shakespeare's A Midsummer Night's Dream}
\normalsize \upshape \par
We also have \texttt{\textbackslash underline}\index{underline@\texttt{\textbackslash underline}} and \texttt{\textbackslash emph}\index{emph@\texttt{\textbackslash emph}} (stands for emphasis). You may want to try them out.

\subsection{Text Color}

\paragraph{Package for More Colors}
While there are built-in colors in the \LaTeX{} system, we can load a variety of additional colors from the \verb|xcolor|\index{xcolor@\texttt{xcolor}} package, often with the \verb|svgnames| and \verb|dvipsnames| flags as
\begin{lstlisting}
\usepackage[svgnames, dvipsnames]{xcolor}    
\end{lstlisting}
The reference color list can be found in \href{https://www.overleaf.com/learn/latex/Using_colors_in_LaTeX}{https://www.overleaf.com/learn/latex/\allowbreak Using\_colors\_in\_LaTeX}. To set the color for a piece of text, we can enclose it with the \texttt{\textbackslash textcolor\{<color\_name>\}\{<text>\}}\index{textcolor@\texttt{\textbackslash textcolor}} command. It is also possible to change the color within a group by \texttt{\textbackslash color\{<color\_name>\}}\index{color@\texttt{\textbackslash color}}. For instance,
\begin{lstlisting}
outputs \par
\textcolor{Red}{Roses are red,} \\
\textcolor{blue}{violets are blue,} \\ 
{\color{Purple} Sugar is sweet and so are you.} % again, remember to limit the scope by curly brackets!
\end{lstlisting}
outputs \par
\textcolor{Red}{Roses are red,} \\
\textcolor{blue}{violets are blue,} \\ 
{\color{Purple} Sugar is sweet and so are you.}

\paragraph{Self-defined Colors}
It is also possible to design a custom color by the command \texttt{\textbackslash definecolor\{<color\_name>\}\{<color\_model>\}\{<values>\}}\index{definecolor@\texttt{\textbackslash definecolor}}. There are $4$ possible color models: \verb|rgb|, \verb|RGB|, \verb|cmyk|, and \verb|gray|. For example,
\begin{lstlisting}
\definecolor{mint}{rgb}{0.24, 0.71, 0.54} % in the preamble
...
\textcolor{mint}{Mint Tears}
\end{lstlisting}
\definecolor{mint}{rgb}{0.24, 0.71, 0.54}gives \textcolor{mint}{Mint Tears}. Color codes can be checked via \href{https://latexcolor.com/}{https://latexcolor.com/}. In addition, we can mix colors by the expression \texttt{<color\_1>!<mix\_ratio>!\allowbreak <color\_2>}\index{Color Mix}. For instance,
\begin{lstlisting}
\textcolor{Blue!40!Green}{Copper (II)} \textcolor{Orange!50}{Sulphate}
\end{lstlisting}
is displayed as \textcolor{Blue!40!Green}{Copper (II)} \textcolor{Orange!50}{Sulphate}.

\section{Paragraphs and Positioning}

\subsection{Paragraphs and Line Breaks}

\paragraph{New Lines}
As explained before, the \texttt{\textbackslash\textbackslash} symbol issues a \textit{line break}\index{Line Break}, and the \texttt{\textbackslash par} command ends a paragraph and starts a new one. \\
Both of them initiate a \textit{new line}\index{New Line}, but with (without) an extra \textit{line skip/line spacing}\index{Line Skip/Spacing} for \texttt{\textbackslash par} (\texttt{\textbackslash\textbackslash}). There is also \texttt{\textbackslash newline}\index{newline@\texttt{\textbackslash newline}} which is similar and sometimes used.
    
A \textit{blank line}\index{Blank Line} in a \texttt{.tex} file has the same effect as \texttt{\textbackslash par}. They, in fact, end the so-called \textit{horizontal mode}\index{Horizontal Mode} and distribute the text into lines held in the current vertical list (see \href{https://tex.stackexchange.com/questions/82664/when-to-use-par-and-when-newline-or-blank-lines}{\TeX{} StackExchange 82664}). \par 
The effects of \texttt{\textbackslash\textbackslash}, \texttt{\textbackslash par}, and blank lines can be observed right in this subsection, which is typed as
\begin{lstlisting}
\paragraph{New Lines}
As explained before, ... ends a paragraph and starts a new one. \\
Both of them initiate a \textit{new line}, ... which is similar and sometimes used.
                % here is a blank line with this comment only
A blank line in a \texttt{.tex} file ... held in the current vertical list (see ...). \par
The effects of \texttt{\textbackslash\textbackslash}, \texttt{\textbackslash par}, and blank lines can be observed right in this subsection, which is typed as
... % this code block, see Section 2.4
\end{lstlisting}

\subsection{Justification and Indents}

\paragraph{Ragged and Centering}
{\raggedright The \texttt{\textbackslash raggedright}\index{raggedright@\texttt{\textbackslash raggedright}} and \texttt{\textbackslash raggedleft}\index{raggedleft@\texttt{\textbackslash raggedleft}} commands produce \textit{left/right-justified}\index{Justification (Text: left, right, fully, center)} text respectively. As you may have figured out, this paragraph is “ragged right” so that the text sticks to the left boundary, but the right side is now uneven. \par}
{\raggedleft Meanwhile, this lipsum text is “ragged left”: \lipsum[4]\par}
The default setting is \textit{fully-justified} so that the text extends to both edges like this one. \texttt{\textbackslash raggedleft} and \texttt{\textbackslash raggedright} act like a switch, changing all paragraphs beyond, and we may want to put them within a group enclosed by curly brackets. \par
{\centering We also have \texttt{\textbackslash centering}\index{centering@\texttt{\textbackslash centering}} which is quite self-explanatory and is demonstrated here. For these three commands to work properly, we require \texttt{\textbackslash par} to finish, similar to before. The code to generate the above paragraphs is \par}
\begin{lstlisting}
\paragraph{Raggedleft/right, Centering}
{\raggedright The \texttt{\textbackslash raggedright} and \texttt{\textbackslash raggedleft} commands produce ... but the right side is now uneven. \par}
{\raggedleft Meanwhile, this lipsum text is "ragged left": \lipsum[4]\par}
The default setting is \textit{fully-justified} ... we may want to put them within a group enclosed by curly brackets. \par
{\centering We also have \texttt{\textbackslash centering} ... The code to generate the above paragraphs is \par}
\end{lstlisting}

\paragraph{Flushing (Environments)}
The alternative to the above is to put the text into a \verb|flushleft|/\verb|flushright|/\verb|center|\index{flushleft@\texttt{flushleft}}\index{flushright@\texttt{flushright}}\index{center@\texttt{center}} environment. An \textit{environment}\index{Environment} contains content that is to be processed and displayed according to the specific design indicated by the environment itself. Environments always start with the \texttt{\textbackslash begin\{<env\_name>\}}\index{begin@\texttt{\textbackslash begin}} and end with the \texttt{\textbackslash end\{<env\_name>\}}\index{end@\texttt{\textbackslash end}} statements. For example, the previous part can also be reproduced by
\begin{lstlisting}
...
\begin{flushright}
Meanwhile, this lipsum text is "ragged left": \lipsum[4]
\end{flushright}
...
\begin{center}
We also have \texttt{\textbackslash centering} ... The code to generate the above paragraphs is
\end{center}
\end{lstlisting}
\texttt{flushleft} (\texttt{flushright}) corresponds to ( \texttt{\textbackslash raggedright}) \texttt{\textbackslash raggedleft}. However, if you test this new code, notice the increased separation\footnote{This is dictated by \texttt{\textbackslash topsep}, see the next subsection.} around the environments. 

\paragraph{Indents, Paragraph Skip}
Attentive readers may have figured out that there is no \textit{indent}\index{Indent} for paragraphs in the book, and they are only separated by a slight vertical spacing. This is controlled by the \verb|parskip=half|\index{parskip@\texttt{parskip}} key inside \texttt{\textbackslash KOMAoptions} in the preamble, which means that paragraphs are identified with a vertical spacing of half a line. The two other options \verb|parskip=no| and \verb|parskip=full| use indents (without vertical spacing) and one full line instead. Also, we can control indents manually by adding \texttt{\textbackslash indent}\index{indent@\texttt{\textbackslash indent}}\footnote{It will not work if \texttt{parskip} is \texttt{half} or \texttt{full} as they take priority.} or \texttt{\textbackslash noindent}\index{noindent@\texttt{\textbackslash noindent}} to the start of paragraphs.

\paragraph{Improved Typesetting}
Finally, for a better typesetting behavior (e.g.\ hyphenation), it is recommended always to import the \verb|microtype|\index{microtype@\texttt{microtype}} package, which provides helpful patches on this.

\begin{exercisebox}
\begin{Exercise}
Try experimenting with different \verb|parskip| options (there are additional modifiers like \verb|half-|, \verb|half+|, \verb|half*|, similar for \verb|full|) for the KOMA-script class, as well as the on-and-off of indents.     
\end{Exercise}
\end{exercisebox}

\subsection{Lengths and Sizes}

\paragraph{Length Units}
Before learning how to adjust the size of objects and spacing, we need to be able to express and measure lengths in \LaTeX{}. There are various \textit{length units}\index{Length Unit} for this, summarized in Table \ref{tab:lengthunit} below.

\begin{table}[ht!]
\begin{tabularx}{\textwidth}{|l|X|}
\hline
Unit & Description \\
\hline
pt & The usual "point" unit adopted in computer documents. \\
\hline
mm/cm/in & A millimeter/A centimeter/An inch. \\
\hline
ex & The height of a lowercase "x" character in the current font. (usually used for vertical distance) \\
\hline
em & The width of an uppercase "M" in the current font. (usually used for horizontal distance) \\
\hline
mu & $1/18$ of an em with respect to the math symbols. (usually used in math mode) \\
\hline
\end{tabularx}
\caption{The various length units in \LaTeX{}.}
\label{tab:lengthunit}
\end{table}

\paragraph{Length Values, Setting Lengths}
Subsequently, the \textit{lengths}\index{Length} of different markers are stored as parameters, listed in Table \ref{tab:lengthpmt}. By using \texttt{\textbackslash setlength\{<length\_\allowbreak param>\}\{<length\_value>\}}\index{setlength@\texttt{\textbackslash setlength}}, we can modify them and adjust distances on the page.

\begin{table}[ht!]
\begin{tabularx}{\textwidth}{|p{0.25\textwidth}|X|}
\hline
Parameter & Description \\
\hline
\texttt{\textbackslash baselineskip} & The vertical distance between adjacent lines within a paragraph.  \\
\hline
\texttt{\textbackslash columnsep} & The distance between columns. \\
\hline
\texttt{\textbackslash columnwidth} & The width of a column. \\
\hline
\texttt{\textbackslash fboxsep} and \texttt{\textbackslash fboxrule} & The padding and line width around boxes. \\
\hline
\texttt{\textbackslash linewidth} & The width of a line. \\
\hline
\texttt{\textbackslash paperheight} and \texttt{\textbackslash paperwidth} & The height and width of the page. \\
\hline
\texttt{\textbackslash parindent} & The length of the indent before a paragraph. \\
\hline
\texttt{\textbackslash parskip} & The vertical spacing between paragraphs. \\
\hline
\texttt{\textbackslash textheight} and \texttt{\textbackslash textwidth} & The height and width of the text area in a page (or in the current environment). \\
\hline
\texttt{\textbackslash topmargin} & The length of the top margin. \\
\hline
\texttt{\textbackslash topsep} and \texttt{\textbackslash itemsep} & The vertical space added above and below an environment, as well as around the items within it. \\
\hline
\end{tabularx}
\caption{Commonly involved length parameters in \LaTeX{}.}
\label{tab:lengthpmt}
\end{table}
\index{baselineskip@\texttt{\textbackslash baselineskip}}\index{columnsep@\texttt{\textbackslash columnsep}}\index{columnwidth@\texttt{\textbackslash columnwidth}}\index{fboxsep@\texttt{\textbackslash fboxsep}}\index{fboxrule@\texttt{\textbackslash fboxrule}}\index{linewidth@\texttt{\textbackslash linewidth}}\index{paperheight@\texttt{\textbackslash paperheight}}\index{paperwidth@\texttt{\textbackslash paperwidth}}\index{parindent@\texttt{\textbackslash parindent}}\index{parskip@\texttt{\textbackslash parskip}}\index{textheight@\texttt{\textbackslash textheight}}\index{textwidth@\texttt{\textbackslash textwidth}}\index{topmargin@\texttt{\textbackslash topmargin}}\index{topsep@\texttt{\textbackslash topsep}}\index{itemsep@\texttt{\textbackslash itemsep}}

\subsection{Horizontal and Vertical Spaces}

\paragraph{Horizontal/Vertical Spaces}
To control the position of different objects or blocks, the primary way is via the \texttt{\textbackslash hspace\{<length>\}}\index{hspace@\texttt{\textbackslash hspace}} and \texttt{\textbackslash vspace\{<\allowbreak length>\}}\index{vspace@\texttt{\textbackslash vspace}} commands. As their names hint, they add a \textit{horizontal/vertical space}\index{Horizontal Space}\index{Vertical Space} of some fixed length. For example, the code
\begin{lstlisting}
\hspace{3ex} Hello \hspace{5ex} World \vspace{1.5em} !!! \\
Ouch...
\end{lstlisting}
gives \par
\hspace{3ex} Hello \hspace{5ex} World \vspace{1.5em} !!! \\
Ouch...\par
The first two \texttt{\textbackslash hspace} commands should work as you have expected, but notice that on the other hand, \texttt{\textbackslash vspace} in the middle of a line will only take effect after it, and so the exclamation marks above are not moved down (but “Ouch...” is). Finally, they accept negative lengths, and you may want to play with that.\par

It is also possible to achieve the same effect after a line break by writing something along the lines of \texttt{\textbackslash\textbackslash [<length>]}, e.g.\
\begin{lstlisting}
Don't come any closer!!!\\[-1em]
Nope *Taking out the axe*
\end{lstlisting}
Don't come any closer!!!\\[-1em]
Nope *Taking out the axe*

\paragraph{Starred Spaces}
There also exist starred versions of \texttt{\textbackslash hspace*\{<length>\}}\index{hspace*@\texttt{\textbackslash hspace*}} and \texttt{\textbackslash vspace*\{<length>\}}\index{vspace*@\texttt{\textbackslash vspace*}}. The difference is that the original ones will be “gobbled up” (see \href{https://tex.stackexchange.com/questions/89082/hspace-vs-hspace}{{\TeX{} StackExchange 89082}}) and disappear at line breaks, but the new ones will not. To see this clearly, let's try
\begin{lstlisting}
x\hspace{3ex}y\\
\hspace{4ex}y?\\
\hspace*{4ex}y!
\end{lstlisting}
which gives \par
x\hspace{3ex}y\\
\hspace{4ex}y?\\
\hspace*{4ex}y!

\paragraph{Fill and Stretch}
In the case where a fixed distance is only needed in a certain place, while other remaining empty spaces can extend automatically, we can make use of the \texttt{\textbackslash hfill}\index{hfill@\texttt{\textbackslash hfill}}, \texttt{\textbackslash vfill}\index{vfill@\texttt{\textbackslash vfill}} commands, or more generally \texttt{\textbackslash fill}\index{fill@\texttt{\textbackslash fill}}, plus \texttt{\textbackslash stretch\{<factor>\}}\index{stretch@\texttt{\textbackslash stretch}}. \texttt{\textbackslash hfill} and \texttt{\textbackslash vfill} will take up all the possible spaces after other \texttt{\textbackslash hspace} or \texttt{\textbackslash vspace} commands are calculated.

If there are multiple \texttt{\textbackslash hfill} or \texttt{\textbackslash vfill}, then the length will be partitioned equally. To assign different weightings to the partition, we can go back and write \texttt{\textbackslash hspace\{\textbackslash stretch\{<factor>\}\}} (similarly for \texttt{\textbackslash vspace}). For example,
\begin{lstlisting}
\hfill Hope \hspace{4cm} Faith \hspace*{\stretch{2}} \\
\hspace*{\stretch{2}} Love \hspace{4cm} Luck \hspace*{\fill} \par % the asterisks * are needed!
\end{lstlisting}
yields \par
\hfill Hope \hspace{4cm} Faith \hspace*{\stretch{2}} \\
\hspace*{\stretch{2}} Love \hspace{4cm} Luck \hspace*{\fill} \par
Notice how we have to use the starred forms to circumvent the gobbling. (Try not using them and see how it fails!)

\paragraph{Skips} Finally, there are also shorthands for generating vertical line skips: \texttt{\textbackslash small\allowbreak skip}\index{smallskip@\texttt{\textbackslash smallskip}}, \texttt{\textbackslash medskip}\index{medskip@\texttt{\textbackslash medskip}}, and \texttt{\textbackslash bigskip}\index{bigskip@\texttt{\textbackslash bigskip}}. Note that they are just \texttt{\textbackslash vspace} with \texttt{\textbackslash smallskipamount}\index{smallskipamount@\texttt{\textbackslash smallskipamount}}, \texttt{\textbackslash medskipamount}\index{medskipamount@\texttt{\textbackslash medskipamount}}, and \texttt{\textbackslash bigskipamount}\index{bigskipamount@\texttt{\textbackslash bigskipamount}} under the hood.

\subsection{Boxes and Rules}

\paragraph{Basic Boxes}
By calling \texttt{\textbackslash mbox\{<text>\}}\index{mbox@\texttt{\textbackslash mbox}}, a piece of text may be placed and contained inside a \textit{horizontal box}\index{Horizontal Box}. This also means that the text will not be disrupted by automatic line breaks or stretched (see \href{https://tex.stackexchange.com/questions/475056/hbox-mbox-difference-what-they-do}{{\TeX{} StackExchange 475056}}), and can spill out of the main area into the margin. There is also \texttt{\textbackslash fbox\{<text>\}}\index{fbox@\texttt{\textbackslash fbox}} as a wrapped version of \texttt{\textbackslash mbox} with a frame around it, and we will use it for a visualized comparison: The code
\begin{lstlisting}
Preparation is the key to success, but a good plan today is better than a perfect plan tomorrow.
\fbox{Preparation is the key to success, but a good plan today is better than a perfect plan tomorrow.}
\end{lstlisting}
produces: Preparation is the key to success, but a good plan today is better than a perfect plan tomorrow.
\fbox{Preparation is the key to success, but a good plan today is better than a perfect plan tomorrow.}
From this, we can clearly see how the horizontal box extends all the way outside.

\paragraph{Advanced Boxes}
An improved version for the box commands above consists of \texttt{\textbackslash makebox[<width>][<alignment>]\{<text>\}}\index{makebox@\texttt{\textbackslash makebox}} and also similarly \texttt{\textbackslash framebox[<width>][<alignment>]\{<text>\}}\index{framebox@\texttt{\textbackslash framebox}}, where we can specify the width of the box and how the text inside is justified (\verb|l, c, r, s|: left, center, right, spread) inside the box. For example,
\begin{lstlisting}
\framebox[100pt][c]{I fit inside!} and \\
\framebox[130pt][l]{Unfortunately, this one is too small for me...}
\end{lstlisting}
generates \framebox[100pt][c]{I fit inside!} and \\
\framebox[130pt][l]{Unfortunately, this one is too small for me...} \\
These box commands can be manipulated to control the distribution of text.

\paragraph{Paragraph Boxes}
Meanwhile, \textit{vertical boxes}\index{Vertical Box} where the text inside can break just like normally can be constructed by the \texttt{\textbackslash parbox[<alignment>]\{<width>\}\allowbreak\{<text>\}}\index{parbox@\texttt{\textbackslash parbox}} command. The effect is not hard to inspect from the input:
\begin{lstlisting}
that produces \parbox[b]{100pt}{Empty your mind, be formless, shapeless, like water.} ...
\end{lstlisting}
that produces \parbox[b]{100pt}{Empty your mind, be formless, shapeless, like water.} This time, the \textit{alignment}\index{Alignment (Text: top, bottom, center)} option (\verb|t, c, b|: top, center, bottom) decides how the \texttt{\textbackslash parbox} will be positioned relative to the current line. To add a frame around it, simply enclose it with an extra \texttt{\textbackslash fbox}.

\paragraph{Raising Boxes}
Sometimes we may want to raise or lower a text while pretending it still occupies some space with a fixed extent. Then the \texttt{\textbackslash raisebox\{<vertical\allowbreak\_distance>\}[<extend\_above>][<extend\_below>]\{<text>\}}\index{raisebox@\texttt{\textbackslash raisebox}} command will do the job. This is demonstrated by including a \texttt{\textbackslash fbox} to visualize the effect:
\begin{lstlisting}
\fbox{\raisebox{15pt}[10pt][10pt]{I am a rising star!}} and this is my stage!
\end{lstlisting}
\fbox{\raisebox{15pt}[10pt][10pt]{I am a rising star!}} and this is my stage!\par
This command can be very useful in achieving several invisible spacing tricks.

\paragraph{Phantom}
Another very similar command is \texttt{\textbackslash phantom\{<text>\}}\index{phantom@\texttt{\textbackslash phantom}} where the text will not be displayed, but the space is still used as it is right there. For example, \texttt{\textbackslash phantom\{Ghost\} Division} outputs: \phantom{Ghost} Division.

\paragraph{Rules}
Another useful ingredient is the possibility to draw \textit{rules}\index{Rule} as lines. The basic command is \texttt{\textbackslash rule\{<horizontal\_extent>\}\{vertical\_extent\}}\index{rule@\texttt{\textbackslash rule}}. For example, \texttt{\textbackslash rule\{5ex\}\{1ex\}} generates this: \rule{5ex}{1ex}. We also have more primitive versions of \texttt{\textbackslash hrule}\index{hrule@\texttt{\textbackslash hrule}} and \texttt{\textbackslash vrule}\index{vrule@\texttt{\textbackslash vrule}}. The code below will yield
\begin{lstlisting}
\vrule \hspace{6pt} If you remove me, the vertical rule to the left will disappear! \hrule
\end{lstlisting}
\vrule \hspace{6pt} If you remove me, the vertical rule to the left will disappear!  \hrule

\begin{exercisebox}
\begin{Exercise}
Use the \texttt{\textbackslash setlength} command to change different lengths and test what the result would look like, e.g.\ \texttt{\textbackslash setlength\{\textbackslash parindent\}\{5cm\}}.
\end{Exercise}
\begin{Exercise}
Copy your favorite quote or paragraph to the document, and use the commands/techniques introduced in these two sections to make it beautiful and stylish.    
\end{Exercise}
\end{exercisebox}

\section{Verbatim Mode}

\paragraph{Verbatim}
To type short inline code pieces, we can use the \textit{verbatim}\index{Verbatim} mode through the \texttt{\textbackslash verb|<content>|}\index{verb@\texttt{\textbackslash verb}} command. This preserves the input exactly as it is typed, without invoking any would-be \LaTeX{} command or special character. For example, entering \texttt{\textbackslash verb|func|} will output \verb|func| here. However, a major pitfall is that \texttt{\textbackslash verb} can fail when it is used inside the argument of a command.\footnote{Interested readers can search for fragile commands.} Since we may use the \texttt{\textbackslash include} command to import each chapter separately as suggested by Section \ref{subsection:TeXorg}, this will be problematic. An alternative is to use \texttt{\textbackslash texttt\{<content>\}}, with \texttt{\textbackslash textbackslash}\index{textbackslash@\texttt{\textbackslash textbackslash}} as the replacement for \texttt{\textbackslash}, and writing \texttt{\textbackslash \_} for \texttt{\_}, \texttt{\textbackslash \{} and \texttt{\textbackslash \}} for \texttt{\{} and \texttt{\}}. 

\paragraph{Code Snippets}
When we need to display larger blocks of code, we can use the \verb|listings|\index{listings@\texttt{listings}} package and its \verb|lstlisting|\index{lstlisting@\texttt{lstlisting}} environment. Actually, it has already been used (shown as yellow areas) in this book many times. A self-explanatory example\footnote{It is a bit involved to make this one work, the option \texttt{escapeinside} (as well as its variants) is intentionally left out below, but you should look it up.} is
\begin{lstlisting}
\begin{lstlisting} % can pass the option [style=<style_name>] to override
\textit{I guess this counts as a recursion...}
\end{lstlisting/*!\}!*/
\end{lstlisting}
To design the appearance of the code blocks, we can define our own \verb|lstlisting| style. The one adopted in the book is given by
\begin{lstlisting}
\lstdefinestyle{lstTeXstyle}{ % give a name for the lstlisting style
    language=[latex]TeX, 
    basicstyle=\footnotesize\ttfamily, % the font style
    backgroundcolor=\color{Goldenrod!20},
    keywordstyle=\color{blue!80}\bfseries, % for highlighting functions
    commentstyle=\color{Green},
    breaklines=true, 
    numbers=none, % none, left, or right
    showstringspaces=false,
    belowskip=0pt}
\lstset{style=lstTeXstyle} % set the style
\end{lstlisting}
Most of the options above are not hard to understand, but you may want to fiddle with the last four of them.

Like \texttt{\textbackslash verb}, this package also comes up with \texttt{\textbackslash lstinline}\index{lstinline@\texttt{\textbackslash lstinline}} for writing inline code.

\begin{exercisebox}
\begin{Exercise}
Take any of the code blocks in this book and reproduce it using the \verb|lstlisting| environment.
\end{Exercise}
\end{exercisebox}