% lua-widow-control
% https://github.com/gucci-on-fleek/lua-widow-control
% SPDX-License-Identifier: MPL-2.0+
% SPDX-FileCopyrightText: 2022 Max Chernoff

\NeedsTeXFormat{LaTeX2e}[2015/01/01] % Formats built after 2015 include \LuaTeX{}Base
\ProvidesPackage{lua-widow-control}%
    [2022/02/22 v1.1.6]

% The version number above is somewhat-misleading: I will make bugfixes to this file
% from time to time, but the core of the file will not change. Therefore, we should
% report a real version number here for debugging.
\PackageInfo{lua-widow-control}{%
    Real version:
    2022/05/14 %%dashdate
    v2.1.0 %%version
}

\PackageWarning{lua-widow-control}{%
    Old LaTeX format detected!\MessageBreak\MessageBreak
    Lua-widow-control prefers a LaTeX format\MessageBreak
    newer than November 2020. I'll still run\MessageBreak
    the latest Lua code, but I'm using an older\MessageBreak
    version of the LaTeX code. This means that\MessageBreak
    the key-value interface is *UNSUPPORTED*.\MessageBreak
}

\ifdefined\directlua\else
    \PackageError{lua-widow-control}{%
        LuaTeX is required for this package.\MessageBreak
        Make sure to compile with `lualatex'%
    }{}
\fi

\clubpenalty=1
\widowpenalty=1
\displaywidowpenalty=1

% We can't use \\newlength since that makes a \TeX{} "skip", not a "dimen"
\newdimen\lwcemergencystretch
\lwcemergencystretch=3em

\newcount\lwcmaxcost
\lwcmaxcost=2147483647

\directlua{require "lua-widow-control"}

% Here, we enable font expansion/contraction. It isn't strictly necessary for
% \lwc/'s functionality; however, it is required for the
% lengthened paragraphs to not have terrible spacing.
\RequirePackage{etoolbox}
\AtEndPreamble{
    \@ifpackageloaded{microtype}{}{ % Only load if not already loaded
        \RequirePackage[
            final,
            activate={true,nocompatibility}
        ]{microtype}
    }
}

% Define \TeX{} wrappers for Lua functions
\newcommand{\lwcenable}{\directlua{lwc.enable_callbacks()}}
\newcommand{\lwcdisable}{\directlua{lwc.disable_callbacks()}}
\newcommand{\iflwc}{\directlua{lwc.if_lwc_enabled()}}

% Enable \lwc/ by default when the package is loaded.
\lwcenable

% Expansion of some parts of the document, such as section headings, is quite
% undesirable, so we'll disable \lwc/ for certain commands.
\newcommand{\lwc@patch@warning}[1]{\PackageWarning{lua-widow-control}{%
    Patching the \protect#1 command failed%
}}

% We should only reenable \lwc/ at the end if it was already enabled.
\newif\iflwc@should@reenable

\newcommand{\lwc@patch@pre}{%
    \iflwc%
        \lwc@should@reenabletrue%
        \lwcdisable%
    \else%
        \lwc@should@reenablefalse%
    \fi%
}

\newcommand{\lwc@patch@post}{%
    \iflwc@should@reenable%
        \lwcenable%
    \fi%
}

\newcommand{\lwcdisablecmd}[1]{%
    \ifdefined#1
        \pretocmd{#1}{\lwc@patch@pre}{}{\lwc@patch@warning{#1}}%
        \apptocmd{#1}{\lwc@patch@post}{}{\lwc@patch@warning{#1}}%
    \fi
}

\lwcdisablecmd{\@sect} % Sectioning


\endinput
