LaTeX/List Structures - Historique des versions

Nicolas Brouard : Customizing list

2011-05-05T08:48:59Z

Customizing list

Nicolas Brouard le 4 mai 2011 à 17:53

2011-05-04T17:53:15Z

Nicolas Brouard : Trying to make it more coherent

2011-05-04T17:51:59Z

Trying to make it more coherent

Nicolas Brouard : /* Customizing Line Spacing in Lists */ error

2011-05-04T17:48:12Z

‎Customizing Line Spacing in Lists : error

Nicolas Brouard le 4 mai 2011 à 17:46

2011-05-04T17:46:25Z

Nicolas Brouard : /* Customizing Line Spacing in Lists */

2011-05-04T17:41:54Z

‎Customizing Line Spacing in Lists

Nicolas Brouard : Borrowed from English wikibooks

2011-04-20T15:15:31Z

Borrowed from English wikibooks

Nouvelle page

<noinclude>{{LaTeX/Top}}</noinclude>
Convenient and predictable list formatting is one of the many advantages of using LaTeX. Many users of wysiwyg word processors are frequently frustrated by the software's clumsy attempts to figure out when you intend lists to begin and end. This is the price of auto-formatting. As a mark-up language, LaTeX gives you ''far'' more control over the structure and content of your list. With a little practice you will find that creating lists in LaTeX is actually a pleasure when compared to wrestling with your typical "high power" word processor.
== List Structures ==

Lists often appear in documents, especially academic, as their purpose is often to present information in a clear and concise fashion. List structures in LaTeX are simply environments which essentially come in three flavors: <source lang="latex" enclose="none">itemize</source>, <source lang="latex" enclose="none">enumerate</source> and <source lang="latex" enclose="none">description</source>.

All lists follow the basic format:

<source lang="latex">
\begin{list_type}

\item The first item
\item The second item
\item The third etc \ldots

\end{list_type}
</source>

All three of these types of lists can have multiple paragraphs per item: just type the additional paragraphs in the normal way, with a blank line between each. So long as they are still contained within the enclosing environment, they will automatically be indented to follow underneath their item.

=== <tt>Itemize</tt> ===

This environment is for your standard bulleted list of items.

{|
|style="border-right:2px black solid;padding-right:3em;"|
<source lang="latex" enclose="none">
\begin{itemize}
\item The first item
\item The second item
\item The third etc \ldots
\end{itemize}
</source>
|style="padding-left:3em;"|
[[Image:itemize.png]]
|}

=== <tt>Enumerate</tt> ===

The enumerate environment is for ordered lists, where by default, each item is numbered sequentially.

{|
|style="border-right:2px black solid;padding-right:3em;"|
<source lang="latex" enclose="none">
\begin{enumerate}
\item The first item
\item The second item
\item The third etc \ldots
\end{enumerate}
</source>
|style="padding-left:3em;"|
[[Image:enum.png]]
|}

=== <tt>Description</tt> ===

The description environment is slightly different. You can specify the item label by passing it as an optional argument (although optional, it would look odd if you didn't include it!). Ideal for a series of definitions, such as a glossary.

{|
|style="border-right:2px black solid;padding-right:3em;"|
<source lang="latex" enclose="none">
\begin{description}
\item[First] The first item
\item[Second] The second item
\item[Third] The third etc \ldots
\end{description}
</source>
|style="padding-left:3em;"|
[[Image:desc.png]]
|}

Sometimes you want a description where the text begins on a new line. This cannot easily be done with <source lang="latex" enclose="none">\\</source>. The trick is to use <source lang="latex" enclose="none">\hfill</source>.
{|
|style="border-right:2px black solid;padding-right:3em;"|
<source lang="latex" enclose="none">
\begin{description}
\item[First] \hfill \\
The first item
\item[Second] \hfill \\
The second item
\item[Third] \hfill \\
The third etc \ldots
\end{description}

</source>
|style="padding-left:3em;"|
[[Image:LaTeX desc-newline.png]]
|}

===Compacted lists===
As you may have noticed, in standard LaTeX document classes, the vertical spacing between items, and above and below the lists as a whole, is more than between paragraphs: it may look odd if the descriptions are too short. If you want tightly-packed lists, use the <tt>mdwlist</tt> package (included in the <tt>mdwtools</tt> bundle), which provides compact, "starred" versions of the previous environments, i.e. <source lang="latex" enclose="none">itemize*</source>, <source lang="latex" enclose="none">enumerate*</source> and <source lang="latex" enclose="none">description*</source>. They work exactly in the same way, but the output is more compact.

Alternatively, use the <tt>memoir</tt> class and with <tt>\tightlists</tt>.

=== Nested Lists ===

Latex will happily allow you to insert a list environment into an existing one (up to a depth of four -- if you need more than four, use the {{LaTeX/Package|easylist}} package). Simply begin the appropriate environment at the desired point within the current list. Latex will sort out the layout and any numbering for you.

{|
| style="vertical-align: middle;border-right:2px black solid;padding-right:3em;" |
<source lang="latex" enclose="none">
\begin{enumerate}
\item The first item
\begin{enumerate}
\item Nested item 1
\item Nested item 2
\end{enumerate}
\item The second item
\item The third etc \ldots
\end{enumerate}
</source>
|style="padding-left:3em;"|
[[Image:nested.png]]
|}

=== Customizing Lists ===

Customizing LaTeX is outside the beginners' domain. While not necessarily difficult in itself, because beginners are already overwhelmed with the array of commands and environments, moving on to more advanced topics runs the risk of confusion.

However, since the tutorial is on formatting, I shall still include a brief guide on customizing lists. Feel free to skip!

==== Customizing Line Spacing in Lists ====

Inside lists you can redefine some length/dimension variables of latex, for example using:

<source lang="latex" enclose="none">
\begin{itemize}
\setlength{\itemsep}{1pt}
\setlength{\parskip}{0pt}
\setlength{\parsep}{0pt}
\item first item
\item second item
\end{itemize}
</source>

Alternatively, to create a unified look in your document you can define your own enumerate environment:

<source lang="latex" enclose="none">
\newenvironment{my_enumerate}
{\begin{enumerate}
\setlength{\itemsep}{1pt}
\setlength{\parskip}{0pt}
\setlength{\parsep}{0pt}}
{\end{enumerate}}
</source>

==== Customizing Enumerated Lists ====

The thing people want to change most often with Enumerated lists are the counters. Therefore, to go any further, a brief introduction to LaTeX ''counters'' is required. Anything that LaTeX automatically numbers, such as section headers, figures, and itemized lists, there is a counter associated with it that controls the numbering.

There are four individual counters that are associated with itemized lists, each one represents the four possible levels of nesting, which are called: <source lang="latex" enclose="none">enumi</source>, <source lang="latex" enclose="none">enumii</source>, <source lang="latex" enclose="none">enumiii</source>, <source lang="latex" enclose="none">enumiv</source>. In order to reset any of these counters in the middle of an enumeration simply use <source lang="latex" enclose="none">\setcounter</source>. The counter is incremented by <source lang="latex" enclose="none">\item</source> before it is printed. For example to reset <source lang="latex" enclose="none">enumi</source> use:

<source lang="latex">
\begin{enumerate}
\setcounter{enumi}{4}
\item fifth element
\end{enumerate}
</source>

which prints as:
5. fifth element

Each counter also has a default format that dictates how it is displayed whenever LaTeX needs to print it. Such formats are specified using internal LaTeX commands:

{| class="wikitable"
! Command
! Example
|-
| <tt>\arabic</tt>
| 1, 2, 3 ...
|-
| <tt>\alph</tt>
| a, b, c ...
|-
| <tt>\Alph</tt>
| A, B, C ...
|-
| <tt>\roman</tt>
| i, ii, iii ...
|-
| <tt>\Roman</tt>
| I, II, III ...
|-
| <tt>\fnsymbol</tt>
| Aimed at footnotes (see below), but prints a sequence of symbols.
|}

Each counter entity holds various bits of information about itself. To get to the numbered element, simply use <source lang="latex" enclose="none">\the</source> followed immediately (i.e., no space) by the name of the counter, e.g., <source lang="latex" enclose="none">\theenumi</source>. This is often referred to as the ''representation'' of a counter.

Now, that's most of the technicalities out of the way. To make changes to the formatting of a given level:
<source lang="latex">
\renewcommand{\representation}{\format_command{counter}}
</source>

Admittedly, the generic version is not that clear, so a couple of examples will clarify:
<source lang="latex">
%Redefine the first level
\renewcommand{\theenumi}{\Roman{enumi}}
\renewcommand{\labelenumi}{\theenumi}

%Redefine the second level
\renewcommand{\theenumii}{\Alph{enumii}}
\renewcommand{\labelenumii}{\theenumii}
</source>

The method used above first explicitly changes the format used by the counter. However, the element that controls the label needs to be updated to reflect the change, which is what the second line does. Another way to achieve this result is this:
<source lang="latex">
\renewcommand{\labelenumi}{\Roman{enumi}}
</source>

This simply redefines the appearance of the label, which is fine, providing that you do not intend to cross-reference to a specific item within the list, in which case the reference will be printed in the previous format. This issue does not arise in the first example.

Note that you can also add other symbols, such as parentheses and periods, before and after the counter. For instance, to create a list indexed by lower case letters with parentheses before and after the letter, you might enter the following:
<source lang="latex">
\renewcommand{\labelenumi}{(\alph{enumi})}
</source>

==== Customizing Itemised Lists ====

Itemized lists are not as complex as they do not need to count. Therefore, to customize, you simply change the labels. It can be done manually for each entry with <source lang="latex" enclose="none">\item[new symbol]</source>, eg <source lang="latex" enclose="none">\item[$\star$]</source>.

The itemize labels are accessed via <source lang="latex" enclose="none">\labelitemi</source>, <source lang="latex" enclose="none">\labelitemii</source>, <source lang="latex" enclose="none">\labelitemiii</source>, <source lang="latex" enclose="none">\labelitemiv</source>, for the four respective levels.
<source lang="latex">
\renewcommand{\labelitemi}{\textgreater}
</source>

The above example would set the labels for the first level to a greater than (>) symbol. Of course, the text symbols available in Latex are not very exciting. Why not use one of the ZapfDingbat symbols, as described in the [[#Other_symbols|Symbols]] section.
Or use a mathematical symbol:
<source lang="latex">
\renewcommand{\labelitemi}{$\star$}
</source>

Itemized list with tightly set items, that is with no vertical space between two consecutive items, can be created as follows.
<source lang="latex">
\begin{itemize}
\setlength{\itemsep}{0cm}%
\setlength{\parskip}{0cm}%
\item Item opening the list
\item Item tightly following
\end{itemize}
</source>

==== Details of Customizing Lists ====
Note that it is necessary that the <source lang="latex" enclose="none">\renewcommand</source> appears after the <source lang="latex" enclose="none">\begin{document}</source> instruction so the changes made are taken into account. This is needed for both enumerated and itemized lists.

=== Inline lists ===
Inline lists are a special case as they require the use of the <tt>paralist</tt> package which provides the <source lang="latex" enclose="none">inparaenum</source> environment (with an optional formatting specification in square brackets):

{|
|style="border-right:2px black solid;padding-right:3em;" |
<source lang="latex" enclose="none">
...
\usepackage{paralist}

\begin{document}

\textbf{\itshape Inline lists}, which are
sequential in nature, just like enumerated
lists, but are
\begin{inparaenum}[\itshape a\upshape)]
\item formatted within their paragraph;
\item usually labelled with letters; and
\item usually have the final item prefixed with
`and' or `or',
\end{inparaenum} like this example.
...
</source>
|style="padding-left:3em;" |[[Image:Latex example paralist.png|400px]]
|}

To change the styles of the counter, tokens A, a, I, i, and 1 can be used in the optional argument to produce the counter with one of the styles <source lang="latex" enclose="none">\Alph</source>, <source lang="latex" enclose="none">\alph</source>, <source lang="latex" enclose="none">\Roman</source>, <source lang="latex" enclose="none">\roman</source> and <source lang="latex" enclose="none">\arabic</source>. For example:
<source lang="latex" >\begin{inparaenum}[(i)]</source>
produces the labels (i), (ii), (iii) ...

← Version précédente		Version du 4 mai 2011 à 17:53
Ligne 118 :		Ligne 118 :
	==== Customizing Line Spacing in Lists ====		==== Customizing Line Spacing in Lists ====

−	~~===Compacted lists===~~
	As you may have noticed, in standard LaTeX document classes article, report or book but not amsart for example, the vertical spacing between items, and above and below the lists as a whole, is more than between paragraphs: it may look odd if the descriptions are too short.		As you may have noticed, in standard LaTeX document classes article, report or book but not amsart for example, the vertical spacing between items, and above and below the lists as a whole, is more than between paragraphs: it may look odd if the descriptions are too short.

@@ Ligne 243 : / Ligne 243 : @@
 Itemized list with tightly set items, that is with no vertical space between two consecutive items, can be created as follows.
-<source lang="latex">
+{|
 \begin{itemize}
    \setlength{\itemsep}{0cm}%
    \setlength{\parskip}{0cm}%
    \item Item opening the list
    \item Item tightly following
 \end{itemize}
 </source>
 ==== Details of Customizing Lists ====

@@ Ligne 88 : / Ligne 88 : @@
 |}
 === Nested Lists ===
@@ Ligne 118 : / Ligne 114 : @@
 Customizing LaTeX is outside the beginners' domain. While not necessarily difficult in itself, because beginners are already overwhelmed with the array of commands and environments, moving on to more advanced topics runs the risk of confusion.
-However, since the tutorial is on formatting, I shall still include a brief guide on customizing lists. Feel free to skip!
+However, since the tutorial is on formatting, I shall still include a brief guide on customizing lists.
 ==== Customizing Line Spacing in Lists ====
 Inside lists you can redefine some length/dimension variables of latex, for example using:
 {|
@@ Ligne 153 : / Ligne 152 : @@
 {\end{enumerate}}
 </source>
 ==== Customizing Enumerated Lists ====

@@ Ligne 135 : / Ligne 135 : @@
 instead of
 \begin{itemize}
    \item first item
    \item second item

@@ Ligne 125 : / Ligne 125 : @@
 <source lang="latex" enclose="none">
 \begin{itemize}
    \setlength{\itemsep}{1pt}