% \iffalse meta-comment
%
% Copyright (C) 2022 by Tanguy Ortolo <tanguy+latex@ortolo.eu>
%
% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions are met:
% 1. Redistributions of source code must retain the above copyright notice,
% this list of conditions and the following disclaimer.
% 2. Redistributions in binary form must reproduce the above copyright notice,
% this list of conditions and the following disclaimer in the documentation
% and/or other materials provided with the distribution.
% 3. Neither the name of the copyright holder nor the names of its
% contributors may be used to endorse or promote products derived from this
% software without specific prior written permission.
%
% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
% POSSIBILITY OF SUCH DAMAGE.
%
% \fi
%
% \iffalse
%<*driver>
\ProvidesFile{songproj.dtx}
%</driver>
%<package>\NeedsTeXFormat{LaTeX2e}[2020/10/01]
%<package>\ProvidesPackage{songproj}
%<*package>
[2023/03/29 v1.2.0 Song projection]
%</package>
%
%<*driver>
\documentclass{l3doc}
\usepackage{fontspec}
\usepackage{bookmark}
\EnableCrossrefs
\CodelineIndex
\RecordChanges
\begin{document}
\DocInput{songproj.dtx}
\PrintChanges
\PrintIndex
\end{document}
%</driver>
% \fi
%
% \CheckSum{269}
%
% \CharacterTable
% {Upper-case \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
% Lower-case \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
% Digits \0\1\2\3\4\5\6\7\8\9
% Exclamation \! Double quote \" Hash (number) \#
% Dollar \$ Percent \% Ampersand \&
% Acute accent \' Left paren \( Right paren \)
% Asterisk \* Plus \+ Comma \,
% Minus \- Point \. Solidus \/
% Colon \: Semicolon \; Less than \<
% Equals \= Greater than \> Question mark \?
% Commercial at \@ Left bracket \[ Backslash \\
% Right bracket \] Circumflex \^ Underscore \_
% Grave accent \` Left brace \{ Vertical bar \|
% Right brace \} Tilde \~}
%
%
% \changes{v0.1.0}{2021/09/19}{Initial version}
% \changes{v0.3.0}{2021/09/26}{Use \textsf{expl3} naming conventions}
% \changes{v1.0.0}{2021/11/07}{First public release}
% \changes{v1.0.1}{2021/11/07}{Add the generated extension file to Git}
% \changes{v1.1.0}{2023/03/27}{Allow couplet numbering with \cs{numbercouplets}}
% \changes{v1.2.0}{2023/03/29}{Allow couplet numbering with \cs{inputsong*}}
%
% \GetFileInfo{songproj.dtx}
%
% \DoNotIndex{\newcommand,\newenvironment}
% \DoNotIndex{\begin,\end}
% \DoNotIndex{\bool,\bool_gset_false:N,\bool_gset_true:N,\bool_if:NTF,\bool_new:N}
% \DoNotIndex{\cs_gset:Npn,\cs_new:Npn}
% \DoNotIndex{\dim,\dim_compare:nNnTF,\dim_new:N,\dim_zero:N}
% \DoNotIndex{\int,\int_compare:nNnTF,\int_gset_eq:NN,\int_new:N,\int_step_function:nN,\int_eval:n,\int_mod:nn,\int_step_inline:nn,\int_use:N}
% \DoNotIndex{\seq,\seq_count:N,\seq_gclear:N,\seq_gput_right:Nn,\seq_gset_from_clist:Nn,\seq_if_empty:NTF,\seq_item:Nn,\seq_map_function:NN,\seq_new:N}
% \DoNotIndex{\tl,\tl_gclear:N,\tl_gset:Nn,\tl_new:N,\tl_use:N,\tl_if_empty:NTF}
% \DoNotIndex{\IfNoValueTF,\NewDocumentCommand,\NewDocumentEnvironment}
% \DoNotIndex{\env,\cmd,\textsf,\vfill}
%
%
% \title{The \textsf{songproj} package\thanks{This document
% corresponds to \textsf{songproj}~\fileversion, dated \filedate.}}
% \author{Tanguy Ortolo \\ \texttt{tanguy+latex@ortolo.eu}}
%
% \maketitle
% \section{Introduction}
%
% This package, together with the \cls{beamer} class, is used to generate
% slideshows with song lyrics. This is typically used in religious services in
% churches equipped with a projector, for which this package has been written,
% but it can be useful for any type of singing assembly\footnote{Indeed, the
% song used here as an example is not really a religious one! It was chosen
% because it is in the public domain and the author likes it.}. It provides
% environments to describe a song in a natural way, and formatting it into
% slides with overlays.
%
% \section{Usage}
%
% \subsection{The \env{song} environment}
%
% The main feature of this package is the \env{song}, that allows the user to
% describe an entire song that will be formatted into slides.
%
% \paragraph{}
% \DescribeEnv{song}
% The \env{song}\marg{stanzas per slide}\oarg{couplet list} environment is used
% around an entire song. It takes a mandatory argument, \meta{stanzas per
% slide}, to specify whether the user wants to show one or two
% stanzas\footnote{including the refrain} on the slide. An optional argument,
% \meta{couplet list} is a comma-separated list of couplet (or verse) indexes,
% that allows the user to indicate that they want to include only these
% couplets of a large song: without this, all couplets will be included.
%
% Inside of the \env{song} environment, the user will use the \cs{longest}
% command and the \env{intro}, \env{refrain}, \env{couplet}\footnote{We
% chose to use the French words \emph{refrain} and \emph{couplet} for several
% reason: the author is French, these words are understandable in English and
% their English equivalents, \emph{chorus} and \emph{verse}, have multiple
% meanings that would make them very ambiguous in both usage and implementation
% of this package.} and \env{final} environments.
%
% \paragraph{Warning} Inside a \env{song} environment, it is an error to write
% anything that is not an \env{intro}, \env{refrain}, \env{couplet},
% \env{final} environment or a \cs{longest} command. Direct text would be
% typeset in a way that would disrupt the song formatting.
%
% \paragraph{}
% \begin{function}{\longest}
% \begin{syntax}
% \cs{longest}\marg{song line}
% \end{syntax}
% Inside a \env{song} environment, the \cs{longest}\marg{song line} command is
% used to declare the longest line of a song, that will be used to properly
% center the song stanzas, as allowed by the \pkg{verse} package. That line
% is only used to compute and record its length, and will not be typeset.
% \end{function}
%
% \changes{v1.1.0}{2023/03/27}{Document the \cs{numbercouplets} command}
% \begin{function}{\numbercouplets}
% \label{doc-cs-numbercouplets}
% Inside a \env{song} environment, the \cs{numbercouplets} command can be used
% to enable couplet numbering. This can be useful when specific couplets have
% been selected but the lead singer has a score a lyrics sheet that includes
% all of them: indicating the couplet numbers in the projection will allow them
% to check which couplet to sing.
% \end{function}
%
% \changes{v0.4.0}{2021/09/29}{Document \env{intro} and \env{final} environments}
%
% \paragraph{}
% \DescribeEnv{intro}
% Inside a \env{song} environment, the optional \env{intro} environment
% declares a number of lines meant to be sung once, at the beginning of the
% song. In a psalm, this may be an antiphon.
%
% \paragraph{}
% \DescribeEnv{refrain}
% Inside a \env{song} environment, the optional \env{refrain} environment
% declares the song refrain (or chorus). A song may start with its refrain, or
% with a first couplet, followed by the refrain. It is not useful to declare
% the refrain several time, as the \env{song} environment will take care of
% repeating between the couplets.
%
% \paragraph{}
% \DescribeEnv{couplet}
% Inside a \env{song} environment, the \env{couplet} environment declares each
% couplet (or verse) of the song.
%
% \paragraph{}
% \DescribeEnv{final}
% Inside a \env{song} environment, the optional \env{final} environment
% declares a number of lines meant to be sung once, at the end of the song. In
% an hymn, that may be a doxology.
%
% \paragraph{Example} \label{example/song}
% The following song is defined with three couplets and a refrain. Since its
% begins with a couplet, it will be formatted with the first couplet, the
% refrain, the second couplet, the refrain, and so on.
%
% The \env{song} environment is given two arguments, |{2}[1,2]|. The first one
% tells it to show two stanzas, that is, both a couplet and the refrain, on the
% generated slide. The second argument tells it to include only the first two
% couplets in the output.
%
% \begin{verbatim}
% \begin{frame}
% \begin{song}{2}[1,2]
% \longest{Light she was, and like a fairy,}
% \begin{couplet}
% In a cavern, in a canyon, \\
% Excavating for a mine. \\
% Dwelt a miner, forty-niner, \\
% And his daughter, Clementine. \\
% \end{couplet}
% \begin{refrain}
% Oh my darling, oh my darling, \\
% Oh my darling Clementine, \\
% You are lost and gone forever, \\
% Dreadful sorry, Clementine. \\
% \end{refrain}
% \begin{couplet}
% Light she was, and like a fairy, \\
% And her shoes were number nine, \\
% Herring boxes, without topses, \\
% Sandals were for Clementine. \\
% \end{couplet}
% \begin{couplet}
% [���]
% \end{couplet}
% \end{song}
% \end{frame}
% \end{verbatim}
%
% \subsection{The \cs{inputsong} command}
% \changes{v1.0.0}{2021/11/07}{Document the \cs{inputsong} command}
% \changes{v1.2.0}{2023/03/29}{Document the \cs{inputsong*} command}
%
% \begin{function}{\inputsong, \inputsong*}
% \begin{syntax}
% \cs{inputsong}\marg{file}\marg{stanzas per slide}\oarg{couplet list}
% \cs{inputsong*}\marg{file}\marg{stanzas per slide}\oarg{couplet list}
% \end{syntax}
%
% The \cs{inputsong} command environment is used as a shortcut for
% typesetting a song written in an external file. That file should contain the
% song content, including intro, refrain, couplet or final as needed, but
% \emph{without} being wrapped in a \env{song} environment.
%
% For instance, one could write a file named \file{clementine.tex} containing
% the \emph{content} of the \env{song} environment shown in example
% page~\pageref{example/song}, and use it in a slideshow:
%
% \begin{verbatim}
% \frame{\inputsong{clementine.tex}{2}[1,2]}
% \end{verbatim}
% \end{function}
%
% The starred version \cs{inputsong*} enables couplet numbering, as described
% in \ref{doc-cs-numbercouplets}.
%
% \subsection{The \env{refrain}, \env{couplet}, \env{intro} and \env{final} environments}
%
% \changes{v0.4.0}{2021/09/29}{Document \env{intro} and \env{final} environments}
%
% These commands are also usable outside of a \env{song} environment. In that
% case, they simply format a refrain or couplet, which can be useful when you
% need more manual control.
%
% \paragraph{}
% \DescribeEnv{refrain}
% Outside of a \env{song} environment, this environment simply wraps its
% content inside a \env{structure} and a \env{verse} environment. It takes an
% optional \meta{verse width} argument, that is used to properly center the
% refrain, as allowed by the \pkg{verse} package.
%
% \paragraph{}
% \DescribeEnv{couplet}
% Outside of a \env{song} environment, this environment simply wraps its
% content inside a \env{verse} environment. It takes an optional \meta{verse
% width} argument, that is used to properly center the refrain, as allowed by
% the \pkg{verse} package.
%
% \paragraph{}
% \DescribeEnv{intro}
% \DescribeEnv{final}
% Outside of a \env{song} environment, these environments simply wrap their
% content inside a \env{em} and a \env{verse} environment. They takes an
% optional \meta{verse width} argument, that is used to properly center the
% refrain, as allowed by the \pkg{verse} package.
%
% \subsection{Usage tips}
%
% For regular offices, there are several suggestions that can ease the creation
% and usage of lyric slideshows.
%
% \subsubsection{Using dedicated song files}
%
% It is suggested to write song lyrics in dedicated files, each containing a
% single the \emph{content} of a \env{song} environment, without the
% environment wrapping itself. They can then be used with the \cs{inputsong}
% command.
%
% For instance, one could write a file named \file{clementine.tex} containing
% the \emph{content} of the \env{song} environment shown in example
% page~\pageref{example/song}. It would then be used in a slideshow such as:
%
% \begin{verbatim}
% \documentclass{beamer}
% \usepackage{songproj}
%
% \begin{document}
% \begin{frame}
% \inputsong{clementine.tex}{2}[1,2,3]
% \end{frame}
% \end{document}
% \end{verbatim}
%
% \subsubsection{Importing text lyrics}
% \changes{v1.1.0}{2023/03/27}{Derivate output file name from input file name if not specified}
%
% Song lyrics are often found in text format with basic markup:
%
% \begin{verbatim}
% 1. In a cavern, in a canon,
% Excavating for a mine.
% Dwelt a miner, forty-niner,
% And his daughter, Clementine.
%
% C. Oh my darling, oh my darling,
% Oh my darling Clementine
% You are lost and gone forever,
% Dreadful sorry Clementine.
%
% 2. Light she was, and like a fairy,
% And her shoes were number nine,
% Herring boxes, without topses,
% Sandals were for Clementine.
%
% [���]
% \end{verbatim}
%
% To avoid the tedious task of manually removing text and adding \LaTeX{}
% markup, we provide the \file{song2tex.py} helper. Please refer to its
% embedded help for detailed instructions about its usage:
%
% \begin{verbatim}
% $ ./song2tex.py --help
% $ ./song2tex.py clementine.txt clementine.tex
% \end{verbatim}
%
% \subsubsection{Projection layout advice}
% \changes{v1.0.0}{2021/11/07}{Add projection layout advice}
%
% During a religious service, a song lyrics projection is only a support, and
% should not draw their attention away from the main feature, which is the
% common prayer.
%
% I therefore suggest using a very simple Beamer theme, such as its default one
% with the \href{https://github.com/rchurchley/beamercolortheme-owl}{owl} color
% theme, and removing the navigation symbols. I also suggest not showing song
% titles (or anything else that is not actually sung by the assembly) unless
% there is a good reason to do so, such as getting used to a song or set of
% songs you intend to reuse often.
%
% \begin{verbatim}
% \documentclass{beamer}
% \usecolortheme{owl}
% \setbeamertemplate{navigation symbols}{}
% \usepackage{songproj}
% \begin{document}
% [���]
% \end{document}
% \end{verbatim}
%
% \subsubsection{Projection advice}
% \changes{v1.0.0}{2021/11/07}{Add projection advice}
%
% For projecting song lyrics, you can take advantage of using a PDF
% presentation software able to show a presenter console on your laptop screen,
% and the current slide on the projector. Software like as
% \href{https://pdfpc.github.io/}{pdfpc} or
% \href{https://github.com/Cimbali/pympress/}{Pympress} can also understand and
% adapt their display to the concept of Beamer overlay.
%
% \StopEventually{}
%
% \section{Implementation}
%
% \subsection{Dependencies}
%
% This module is written using \LaTeX3 programming interfaces and command
% definitions:
%
% \begin{macrocode}
\RequirePackage{expl3}
\RequirePackage{xparse}
% \end{macrocode}
%
% The implementation of the \env{song} environment and its friends is mainly
% based on the \textsf{verse} package:
%
% \begin{macrocode}
\RequirePackage{verse}
% \end{macrocode}
%
% \subsection{Internal definitions}
%
% Almost all definitions use the \textsf{expl3} syntax:
%
% \begin{macrocode}
\ExplSyntaxOn
% \end{macrocode}
%
% \subsubsection{Internal variables}
%
% \changes{v0.2.0}{2021/09/23}{Use \texttt{sp} prefix for functions and
% variables}
% \changes{v1.1.0}{2023/03/27}{Add the \cs{g__sp_show_numbers_bool} variable to
% number or not couplets}
%
% We define a number of internal variables, that are used when reading and
% formatting a song. All of these variables are meant to be set globally: since
% there is no notion of a song within a song, we are certain that we will
% always be either outside of a song or inside a single song.
%
% \begin{macrocode}
\bool_new:N \g__sp_song_bool % are we in a song?
\bool_new:N \g__sp_song_start_bool % are we at the start of a song?
\bool_new:N \g__sp_refrain_first_bool % does current song start with the
% refrain?
\bool_new:N \g__sp_show_numbers_bool % should we show the couplet numbers?
\int_new:N \g__sp_stanzas_per_slide_int % number of stanzas to show on each
% slide (1 or 2)
\dim_new:N \g__sp_linewidth_dim % length of the longest line in current
% song
\tl_new:N \g__sp_intro_tl % current song intro
\tl_new:N \g__sp_refrain_tl % current song refrain
\seq_new:N \g__sp_couplets_seq % current song couplets
\tl_new:N \g__sp_final_tl % current song final
\seq_new:N \g__sp_couplet_indexes_seq % indexes of couplets to include
% \end{macrocode}
%
% \subsubsection{Internal environments}
%
% These are high-level internal environments, that are used in the
% implementation of user interface environments.
%
% \begin{environment}{__sp_refrain}
% This environment simply formats a song refrain. It is used in the user interface
% \env{refrain} environment.
%
% \begin{macrocode}
\NewDocumentEnvironment {__sp_refrain} {}
% The environment opening may be followed by a [length], in fact part of its
% body, and will appear just after the opening of the verse environment and
% constitute its optional argument.
{
\begin{structureenv}
\begin{verse}
}
{
\end{verse}
\end{structureenv}
}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{__sp_couplet}
% This environment simply formats a song couplet. It is used in the user interface
% \env{couplet} environment.
%
% \begin{macrocode}
\NewDocumentEnvironment {__sp_couplet} {}
% The environment opening may be followed by a [length], in fact part of its
% body, and will appear just after the opening of the verse environment and
% constitute its optional argument.
{ \begin{verse} }
{ \end{verse} }
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{__sp_special} {}
%
% \changes{v0.4.0}{2021/09/29}{Add an environment to format intro and final}
%
% This environments simply formats a song intro of final. It is used in the
% user interface \env{intro} and \env{final} environments.
%
% \begin{macrocode}
\NewDocumentEnvironment {__sp_special} {}
% The environment opening may be followed by a [length], in fact part of its
% body, and will appear just after the opening of the verse environment and
% constitute its optional argument.
{
\begin{em}
\begin{verse}
}
{
\end{verse}
\end{em}
}
% \end{macrocode}
% \end{environment}
%
% \subsubsection{Internal macros}
% \changes{v0.3.0}{2021/09/26}{Define aux functions at top-level}
%
% These are macros that are used in the implementation of the \env{song}
% environment.
%
% \begin{macro}{\__sp_song_refrain}
%
% This macro uses the \env{__sp_refrain} environment to format the current song
% refrain.
%
% \begin{macrocode}
\tl_gset:Nn \__sp_song_refrain
{
% Do we know the width of the longest song line?
\dim_compare:nNnTF \g__sp_linewidth_dim {=} {0pt}
{ \begin{__sp_refrain} }
{ \begin{__sp_refrain} [\g__sp_linewidth_dim] }
\tl_use:N \g__sp_refrain_tl
\end{__sp_refrain}
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\__sp_song_couplet:n}
% \changes{v1.1.0}{2023/03/27}{Print the couplet number when requested}
%
% This macro uses the \env{__sp_couplet} environment to format a specified couplet of
% the current song. It takes a single argument:
%
% \begin{arguments}
% \item index of the couplet to format.
% \end{arguments}
%
% \begin{macrocode}
\cs_gset:Npn \__sp_song_couplet:n #1
{
% Do we know the width of the longest song line?
\dim_compare:nNnTF \g__sp_linewidth_dim {=} {0pt}
{ \begin{__sp_couplet} }
{ \begin{__sp_couplet} [\g__sp_linewidth_dim] }
\bool_if:NTF \g__sp_show_numbers_bool
{ \flagverse{#1.} }
{}
\seq_item:Nn \g__sp_couplets_seq {#1}
\end{__sp_couplet}
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\__sp_song_couplets:n}
%
% This macro inserts an containing all couplets of the current song in an
% \env{overprint} environment, in groups separated with \cs{onslide}
% commands. It takes a single argument:
%
% \begin{arguments}
% \item number of couplets to show together on each slide.
% \end{arguments}
%
% \begin{macrocode}
\cs_gset:Npn \__sp_song_couplets:n #1
{
\begin{overprint}
% Loop on all specified couplets
\int_step_inline:nn
{ \seq_count:N \g__sp_couplet_indexes_seq }
{
% Before every #1 lines, i.e. when (##1 - 1) mod #1 == 0),
% insert an \onslide
\int_compare:nNnTF
{ \int_mod:nn { \int_eval:n{##1 - 1} } {#1} } { = } { 0 }
{ \onslide<+> }
{ \vskip \stanzaskip }
\__sp_song_couplet:n { \seq_item:Nn \g__sp_couplet_indexes_seq {##1} }
}
\end{overprint}
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\__sp_song_intro}
%
% \changes{v0.4.0}{2021/09/29}{Add an environment to format current song intro}
%
% This macro uses the \env{__sp_special} environment to format the current song
% intro.
%
% \begin{macrocode}
\tl_gset:Nn \__sp_song_intro
{
% Do we know the width of the longest song line?
\dim_compare:nNnTF \g__sp_linewidth_dim {=} {0pt}
{ \begin{__sp_special} }
{ \begin{__sp_special} [\g__sp_linewidth_dim] }
\tl_use:N \g__sp_intro_tl
\end{__sp_special}
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\__sp_song_final}
%
% \changes{v0.4.0}{2021/09/29}{Add an environment to format current song final}
%
% This macro uses the \env{__sp_refrain} environment to format the current song
% final.
%
% \begin{macrocode}
\tl_gset:Nn \__sp_song_final
{
% Do we know the width of the longest song line?
\dim_compare:nNnTF \g__sp_linewidth_dim {=} {0pt}
{ \begin{__sp_special} }
{ \begin{__sp_special} [\g__sp_linewidth_dim] }
\tl_use:N \g__sp_final_tl
\end{__sp_special}
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\__sp_song}
%
% \changes{v0.4.0}{2021/09/29}{Include intro and final in complete song}
%
% This macro inserts the entire song, alternating refrain and couplets in an
% \env{overprint} environment.
%
% \begin{macrocode}
\tl_gset:Nn \__sp_song
{
% Is there a song intro?
\tl_if_empty:NTF \g__sp_intro_tl
{}
{
\visible<1> {\__sp_song_intro}
% The combination of overprint with verse that comes next somehow adds
% extra vertical space that needs to be removed.
\vskip -\stanzaskip
}
\begin{overprint}
% Does the song begin with the refrain?
\bool_if:NTF \g__sp_refrain_first_bool
{
% If so, print an initial refrain
\onslide<+>
\__sp_song_refrain
}
{}
% Is there a refrain?
\tl_if_empty:NTF \g__sp_refrain_tl
{
% No refrain, loop on all specified couplets and insert them
\seq_map_inline:Nn
\g__sp_couplet_indexes_seq
{
\onslide<+>
\__sp_song_couplet:n {#1}
}
}
{
% There is a refrain, loop on all specified couplets and, each time,
% insert both a couplet and the refrain
\seq_map_inline:Nn
\g__sp_couplet_indexes_seq
{
\onslide<+>
\__sp_song_couplet:n {#1}
\onslide<+>
\__sp_song_refrain
}
}
\end{overprint}
% Is there a song final?
\tl_if_empty:NTF \g__sp_final_tl
{}
{
% Add extra spacing
\vskip \stanzaskip
\visible<.> {\__sp_song_final}
}
}
% \end{macrocode}
% \end{macro}
%
% \subsection{User interface}
%
% These environments constitute our user interface. They allow the user to
% define songs, refrains and couplets.
%
% \begin{environment}{refrain}
% This environment handles a refrain :
% \begin{itemize}
% \item outside of a song, it uses the \env{__sp_refrain} environment to
% directly format it ;
% \item inside a song, it stores it into \cs{g__sp_retrain_tl}, so it can
% be formatted by the end of the \env{song} environment.
% \end{itemize}
%
% \begin{macrocode}
\NewDocumentEnvironment {refrain} { +b }
% The environment opening may be followed by a [length], in fact part of its
% body, and will appear just after the opening of the __sp_refrain
% environment and constitute its optional argument.
{
% Are we in a song?
\bool_if:NTF \g__sp_song_bool
{
% We are in a song, are we at its start?
\bool_if:NTF \g__sp_song_start_bool
{
% Indicate that we are no longer at the start of the song
\bool_gset_false:N\g__sp_song_start_bool
% and that the refrain comes first
\bool_gset_true:N\g__sp_refrain_first_bool
}
{}
% Anyway, store the refrain
\tl_gset:Nn \g__sp_refrain_tl {#1}
}
{
% We are not in a song, use __sp_refrain to format the refrain
\begin{__sp_refrain}
#1
\end{__sp_refrain}
}
}
{}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{couplet}
% This environment handles a couplet, in a similar way:
% \begin{itemize}
% \item outside of a song, it uses the \env{__sp_couplet} environment to
% directly format it ;
% \item inside a song, it stores it by appending it to to
% \cs{g__sp_couplets_seq}, so it can be formatted by the end of the
% \env{song} environment.
% \end{itemize}
%
% \begin{macrocode}
\NewDocumentEnvironment {couplet} { +b }
% The environment opening may be followed by a [length], in fact part of its
% body, and will appear just after the opening of the __sp_couplet
% environment and constitute its optional argument.
{
% Are we in a song?
\bool_if:NTF \g__sp_song_bool
{
% Are we at in a song, are we at its start?
\bool_if:NTF \g__sp_song_start_bool
{
% Indicate that we are no longer at the start of the song
\bool_gset_false:N \g__sp_song_start_bool
% and that the refrain does not come first
\bool_gset_false:N \g__sp_refrain_first_bool
}
{}
% Anyway, store this couplet
\seq_gput_right:Nn \g__sp_couplets_seq { {#1} }
}
{
% We are not in a song, use __sp_couplet to format this couplet
\begin{__sp_couplet}
#1
\end{__sp_couplet}
}
}
{}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{intro}
%
% \changes{v0.4.0}{2021/09/29}{Add an \env{intro} environment}
%
% This environment handles a song intro, in a similar way:
% \begin{itemize}
% \item outside of a song, it uses the \env{__sp_special} environment to
% directly format it;
% \item inside a song, it stores it into \cs{g__sp_intro_tl} so it can be
% formatted by the end of the \env{song} environment.
% \end{itemize}
%
% \begin{macrocode}
\NewDocumentEnvironment {intro} { +b }
% The environment opening may be followed by a [length], in fact part of its
% body, and will appear just after the opening of the __sp_special
% environment and constitute its optional argument.
{
% Are we in a song?
\bool_if:NTF \g__sp_song_bool
{
% We are in a song, store its intro
\tl_gset:Nn \g__sp_intro_tl {#1}
}
{
% We are not in a song, use __sp_special to format the intro
\begin{__sp_special}
#1
\end{__sp_special}
}
}
{}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{final}
%
% \changes{v0.4.0}{2021/09/29}{Add a \env{final} environment}
%
% This environment handles a song final, in a similar way:
% \begin{itemize}
% \item outside of a song, it uses the \env{__sp_special} environment to
% directly format it;
% \item inside a song, it stores it into \cs{g__sp_final_tl} so it can be
% formatted by the end of the \env{song} environment.
% \end{itemize}
%
% \begin{macrocode}
\NewDocumentEnvironment {final} { +b }
% The environment opening may be followed by a [length], in fact part of its
% body, and will appear just after the opening of the __sp_special
% environment and constitute its optional argument.
{
% Are we in a song?
\bool_if:NTF \g__sp_song_bool
{
% We are in a song, store its intro
\tl_gset:Nn \g__sp_final_tl {#1}
}
{
% We are not in a song, use __sp_special to format the intro
\begin{__sp_special}
#1
\end{__sp_special}
}
}
{}
% \end{macrocode}
% \end{environment}
%
% \begin{macro}{\longest}
% This macro measures the length of a song line and stores it, so it can be
% used by the \env{song} environment to properly center refrain and couplets.
% It takes a single argument:
%
% \begin{arguments}
% \item a song line to measure.
% \end{arguments}
%
% \begin{macrocode}
\NewDocumentCommand {\longest} { m } { \settowidth {\g__sp_linewidth_dim} {#1} }
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\numbercouplets}
% \changes{v1.1.0}{2023/03/27}{New command to enable couplet numbering}
%
% This macro can be used within a song to indicate that its couplets should be
% numbered.
%
% \begin{macrocode}
\NewDocumentCommand {\numbercouplets}{}
{ \bool_gset_true:N \g__sp_show_numbers_bool }
% \end{macrocode}
% \end{macro}
%
% \begin{environment}{song}
% \changes{v1.1.0}{2023/03/27}{Do not number couplets by default}
%
% This environment is used as a container for entire songs. On opening, it does several things:
% \begin{enumerate}
% \item its stores its arguments into variables with a descriptive name;
% \item it clears out any previously stored refrain, couplet, intro, final
% and longest song line;
% \item it sets the \cs{g__sp_song_bool} variable to indicate that we
% are inside a song, which will alter the behaviour of the
% \env{refrain} and \env{couplet} environments so they record their
% content rather than directly formatting it into the document;
% \item it sets the \cs{g__sp_song_start_bool} variable to indicate that
% we are at the start of the song, which will allow the next
% \env{refrain} or \env{couplet} to tell if the song starts with the
% refrain or with a couplet;
% \item it sets the \cs{g__sp_show_numbers_bool} variable to false, to
% indicate that the couplets should not be numbered by default (the user
% will be able to override this with the \cs{numbercouplets} command).
% \end{enumerate}
%
% This environment takes two arguments:
%
% \begin{arguments}
% \item number of stanzas (counting couplets and refrain, when there is one) per slide;
% \item list of couplets to include (defaults to all), for instance |1,3,4|.
% \end{arguments}
%
% \begin{macrocode}
\NewDocumentEnvironment {song} { m o }
% {number of stanzas per slide (1 or 2)}
% [list of couplets to include (defaults to all)]
{
% Put arguments into variables with understandable names
\int_gset_eq:NN {\g__sp_stanzas_per_slide_int} {#1}
\IfNoValueTF {#2}
{ \seq_gclear:N \g__sp_couplet_indexes_seq }
{ \seq_gset_from_clist:Nn \g__sp_couplet_indexes_seq {#2} }
% Clear out intro, refrain, couplet, final and longest song line
\tl_gclear:N \g__sp_intro_tl
\tl_gclear:N \g__sp_refrain_tl
\seq_gclear:N \g__sp_couplets_seq
\tl_gclear:N \g__sp_final_tl
\dim_zero:N {\g__sp_linewidth_dim}
% Indicate that we are in a song, and at its start
\bool_gset_true:N \g__sp_song_bool
\bool_gset_true:N \g__sp_song_start_bool
% Couplets should not be numbered by default
\bool_gset_false:N \g__sp_show_numbers_bool
}
% \end{macrocode}
%
% And on closing:
% \begin{itemize}
% \item if no list of couplet indexes to use have been given, it generates one
% covering all couplets in order;
% \item it uses internal functions to insert the intro, refrain, couplets and
% final into the document, in the right order according to the song
% structure (refrain or couplet first) and to the formatting instructions
% (one or two stanzas per slide).
% \end{itemize}
%
% \changes{v0.4.0}{2021/09/29}{Include intro and final in formatted song}
%
% \begin{macrocode}
{
% Have we been given indexes of specific couplets to use?
\seq_if_empty:NTF \g__sp_couplet_indexes_seq
{
% If not, generate it from the list of couplets
\int_step_inline:nn
{ \seq_count:N \g__sp_couplets_seq }
{ \seq_gput_right:Nn \g__sp_couplet_indexes_seq {##1} }
}
{}
% Now we actually start inserting things into the document.
% How many stanzas per side did the user request?
\int_compare:nNnTF \g__sp_stanzas_per_slide_int {>} {1}
{
% More than one stanza per slide
%
% Is there an intro?
\tl_if_empty:NTF \g__sp_intro_tl
{}
{
\visible<1> {\__sp_song_intro}
% Adjust vertical spacing depending on whether the refrain or the
% couplets follow.
\bool_if:NTF\g__sp_refrain_first_bool
{
% Refrain comes next, add extra space
\vskip \parsep
}
{
% Couplets come next, the combination of their overprint and
% verse environment somehow adds extra vertical space that
% needs to be removed.
\vskip -\stanzaskip
}
}
% Is there a refrain?
\tl_if_empty:NTF \g__sp_refrain_tl
{
% If there is no refrain, we use \__sp_song_couplets:n to write the
% couplets, \g__sp_stanzas_per_slide_int at a time.
\__sp_song_couplets:n { \int_use:N \g__sp_stanzas_per_slide_int }
}
{
% If there is a refrain, we use \__sp_song_refrain to write the
% refrain and \__sp_song_couplets:n to write overprint with all
% couplets.
% Does the song begin with the refrain?
\bool_if:NTF\g__sp_refrain_first_bool
{
\__sp_song_refrain
\vskip -\stanzaskip
\__sp_song_couplets:n 1
}
{
\__sp_song_couplets:n 1
\vskip \stanzaskip
\__sp_song_refrain
}
}
% Is there a final?
\tl_if_empty:NTF \g__sp_final_tl
{}
{
% Adjust vertical spacing depending on whether we follow the
% refrain or the couplets.
\tl_if_empty:NTF \g__sp_refrain_tl
{
% No refrain, we follow the couplets, add extra space
\vskip \stanzaskip
}
{
% There was a refrain, did it come first?
\bool_if:NTF \g__sp_refrain_first_bool
{
% Refrain came first, we follow the couplets, add extra space
\vskip \stanzaskip
}
{
% Refrain came last, we follow it, add extra space
\vskip \parsep
}
}
\visible<.> {\__sp_song_final}
}
}
{
% If the user requested one stanza per slide, we use \__sp_song to
% write the entire song in a single overprint environment.
\__sp_song
}
% Indicate that we are no longer in a song
\bool_gset_false:N\g__sp_song_bool
}
% \end{macrocode}
% \end{environment}
%
% \begin{macro}{\inputsong}
% \changes{v1.0.0}{2021/11/07}{Add an \cs{inputsong} command}
% \changes{v1.2.0}{2023/03/29}{Add an \cs{inputsong*} command}
%
% This macro starts a \env{song} environment and \cs{input}s the song content
% from an external file.
%
% \begin{macrocode}
\NewDocumentCommand {\inputsong} { s m m o }
{
\IfNoValueTF {#4}
{ \begin{song} {#3} }
{ \begin{song} {#3} [#4] }
\IfBooleanT {#1}
{ \numbercouplets }
\input{#2}
\end{song}
}
% \end{macrocode}
% \end{macro}
%
% \subsection{Wrapping up}
%
% Now that we have defined everything we need, we can leave the \textsf{expl3}
% syntax and return to normal \TeX{} syntax:
%
% \begin{macrocode}
\ExplSyntaxOff
% \end{macrocode}
%
% \Finale
\endinput