% \iffalse meta-comment
%
%% File: tagpdf-space.dtx
%
% Copyright (C) 2019-2024 Ulrike Fischer
%
% It may be distributed and/or modified under the conditions of the
% LaTeX Project Public License (LPPL), either version 1.3c of this
% license or (at your option) any later version. The latest version
% of this license is in the file
%
% https://www.latex-project.org/lppl.txt
%
% This file is part of the "tagpdf bundle" (The Work in LPPL)
% and all files in that bundle must be distributed together.
%
% -----------------------------------------------------------------------
%
% The development version of the bundle can be found at
%
% https://github.com/latex3/tagpdf
%
% for those people who are interested.
%<*driver>
\DocumentMetadata{}
\documentclass{l3doc}
\usepackage{array,booktabs,caption}
\hypersetup{pdfauthor=Ulrike Fischer,
pdftitle=tagpdf-space module (tagpdf)}
\begin{document}
\DocInput{\jobname.dtx}
\end{document}
%</driver>
% \fi
% \title{^^A
% The \pkg{tagpdf-space} module\\ Code related to real space chars ^^A
% \\ Part of the tagpdf package
% }
%
% \author{^^A
% Ulrike Fischer\thanks
% {^^A
% E-mail:
% \href{mailto:fischer@troubleshooting-tex.de}
% {fischer@troubleshooting-tex.de}^^A
% }^^A
% }
%
% \date{Version 0.99f, released 2024-09-16}
% \maketitle
% \begin{documentation}
% \begin{function}{activate/space (setup-key),interwordspace (deprecated)}
% This key allows to activate/deactivate the real space chars if the engine supports
% it. The allowed values are |true|, |on|, |false|, |off|.
% The old name of the key |interwordspace| is still supported but deprecated.
% \end{function}
% \begin{function}{show-spaces (deprecated)}
% This key is deprecated. Use |debug/show=spaces| instead.
% This key works only with luatex and shows with small red
% bars where spaces have been inserted. This is only for debugging and
% is not completely reliable (and change affect other literals and tagging), so it
% should be used with care.
% \end{function}
% \end{documentation}
% \begin{implementation}
% \begin{macrocode}
%<@@=tag>
%<*header>
\ProvidesExplPackage {tagpdf-space-code} {2024-09-16} {0.99f}
{part of tagpdf - code related to real space chars}
%</header>
% \end{macrocode}
% \section{Code for interword spaces}
% The code is engine/backend dependent. Basically only pdftex and luatex
% support real space chars. Most of the code for luatex which uses attributes
% is in the lua code, here are only the keys.
%
% \begin{macro}{activate/spaces (setup-key),interwordspace (deprecated),show-spaces (deprecated)}
% \begin{macrocode}
%<*package>
\bool_new:N\l_@@_showspaces_bool
\keys_define:nn { @@ / setup }
{
activate/spaces .choice:,
activate/spaces/true .code:n =
{ \msg_warning:nne {tag}{sys-no-interwordspace}{\c_sys_engine_str} },
activate/spaces/false .code:n=
{ \msg_warning:nne {tag}{sys-no-interwordspace}{\c_sys_engine_str} },
activate/spaces .default:n = true,
debug/show/spaces .code:n = {\bool_set_true:N \l_@@_showspaces_bool},
debug/show/spacesOff .code:n = {\bool_set_false:N \l_@@_showspaces_bool},
% \end{macrocode}
% deprecated versions:
% \begin{macrocode}
interwordspace .choices:nn = {true,on}{\keys_set:nn{@@/setup}{activate/spaces={true}}},
interwordspace .choices:nn = {false,off}{\keys_set:nn{@@/setup}{activate/spaces={false}}},
interwordspace .default:n = {true},
show-spaces .choice:,
show-spaces/true .meta:n = {debug/show=spaces},
show-spaces/false .meta:n = {debug/show=spacesOff},
show-spaces .default:n = true
}
\sys_if_engine_pdftex:T
{
\sys_if_output_pdf:TF
{
\pdfglyphtounicode{space}{0020}
\keys_define:nn { @@ / setup }
{
activate/spaces/true .code:n = { \AddToHook{shipout/firstpage}[tagpdf/space]{\pdfinterwordspaceon} },
activate/spaces/false .code:n = { \RemoveFromHook{shipout/firstpage}[tagpdf/space] },
activate/spaces .default:n = true,
}
}
{
\keys_define:nn { @@ / setup }
{
activate/spaces .choices:nn = { true, false }
{ \msg_warning:nnn {tag}{sys-no-interwordspace}{dvi} },
activate/spaces .default:n = true,
}
}
}
\sys_if_engine_luatex:T
{
\keys_define:nn { @@ / setup }
{
activate/spaces .choice:,
activate/spaces/true .code:n =
{
\bool_gset_true:N \g_@@_active_space_bool
\lua_now:e{ltx.@@.func.markspaceon()}
},
activate/spaces/false .code:n =
{
\bool_gset_false:N \g_@@_active_space_bool
\lua_now:e{ltx.@@.func.markspaceoff()}
},
activate/spaces .default:n = true,
debug/show/spaces .code:n =
{\lua_now:e{ltx.@@.trace.showspaces=true}},
debug/show/spacesOff .code:n =
{\lua_now:e{ltx.@@.trace.showspaces=nil}},
}
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@@_fakespace:}
% For luatex we need a command for the fake space as equivalent of the pdftex
% primitive.
% \begin{macrocode}
\sys_if_engine_luatex:T
{
\cs_new_protected:Nn \@@_fakespace:
{
\group_begin:
\lua_now:e{ltx.@@.func.fakespace()}
\skip_horizontal:n{\c_zero_skip}
\group_end:
}
}
% \end{macrocode}
%
% We need also a command to interrupt the insertion of real space
% chars in places where we want to insert manually special spaces.
% In pdftex this can be done with \cs{pdfinterwordspaceoff}
% and \cs{pdfinterwordspaceon}. These commands insert whatsits
% and this mean they act globally. In luatex a attribute is
% used to this effect, for consistency this is also set globally.
%
%
% \begin{macro}{\tag_spacechar_on:,\tag_spacechar_off:}
% The off command sets the attributes in luatex.
% \begin{macrocode}
\cs_new_protected:Npn \tag_spacechar_off: {}
\cs_new_protected:Npn \tag_spacechar_on: {}
\sys_if_engine_luatex:T
{
\cs_set_protected:Npn \tag_spacechar_off:
{
\lua_now:e
{
tex.setattribute
(
"global",
luatexbase.attributes.g_@@_interwordspaceOff_attr,
1
)
}
}
\cs_set_protected:Npn \tag_spacechar_on:
{
\lua_now:e
{
tex.setattribute
(
"global",
luatexbase.attributes.g_@@_interwordspaceOff_attr,
-2147483647
)
}
}
}
\sys_if_engine_pdftex:T
{
\sys_if_output_pdf:T
{
\cs_set_protected:Npn \tag_spacechar_off:
{
\pdfinterwordspaceoff
}
\cs_set_protected:Npn \tag_spacechar_on:
{
\pdfinterwordspaceon
}
}
}
% \end{macrocode}
% \end{macro}
% \begin{macrocode}
%</package>
% \end{macrocode}
% \end{macro}
% \end{implementation}
% \PrintIndex