latexbangla_exp.sty

% ----------------------------------------------------------------
% LaTeXbangla package - Enhanced LaTeX integration for Bangla
% E-mail: adib.hasan8@gmail.com
% Released under the LaTeX Project Public License v1.3c or later
% See http://www.latex-project.org/lppl.txt
% ----------------------------------------------------------------
% This package simplifies the process of writing Bangla in LaTeX and
% addresses most of the common typesetting issues. Additional features
% include automatic transition between languages and many more. (See
% examples) The user can just type in usual LaTeX syntax and expect
% everything to work as it should.
% ------------------------------------------------------------------
% Copyright (C) 2016 by Adib Hasan adib.hasan8@gmail.com

% This work 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:

% http://www.latex-project.org/lppl.txt

% This work is "maintained" (as per LPPL maintenance status) by
% Adib Hasan

% This work consists of the files:  latexbangla.sty,
%                                   latexbangla.tex, and
%                                   latexbangla.pdf
%
%
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{latexbangla_exp}[2016/10/31 v0.2 Enhanced LaTeX integration for Bangla]

\RequirePackage{polyglossia, fontspec, xkeyval, ifxetex}

% Because this package depends on ucharclasses which itself
% requires XeTeX's interchar classes
\RequireXeTeX

%Fully supported Bangla Fonts
%Other banglafonts *are* supported but there might be issues with whitespaces.
\def\@@Kalpurush{Kalpurush}
\def\@Kalpurush#1{
	\ifcase#1{Kalpurush}    %name
	\or{MatchLowercase}     %Scale
	\or{1.1}                %main WordSpace
	\or{1.5}                %tt WordSpace
	\else\fi
}
\def\@@SiyamRupali{SiyamRupali}
\def\@SiyamRupali#1{
	\ifcase#1{SiyamRupali}  %name
	\or{0.8}                %Scale
	\or{1.2}                %main WordSpace
	\or{1.8}                %tt WordSpace
	\else\fi
}
\def\@@SolaimanLipi{SolaimanLipi}
\def\@SolaimanLipi#1{
	\ifcase#1{SolaimanLipi} %name
	\or{0.9}                %Scale
	\or{1.5}                %main WordSpace
	\or{2.1}                %tt WordSpace
	\else\fi
}

\DeclareOptionX{banglamainfont}{%
	\if\relax\detokenize{#1}\relax
		\errmessage{Bangla main font not defined}
	\else
		\def\bm@name{#1}
		\def\bm@@name{bmfont}
		\bm@init{\bm@name}
    \fi
}
\DeclareOptionX{banglattfont}{%
	\if\relax\detokenize{#1}\relax
		\errmessage{Bangla tt font not defined}
	\else
		\def\btt@name{#1}
		\def\btt@@name{bttfont}
		\btt@init{\btt@name}
    \fi
}

\newif\if@none
\newif\if@recom
\newif\if@full
\@recomtrue
\DeclareOptionX{feature}{
	\if\relax\detokenize{#1}\relax\fi
	\ifcase#1
		\@recomfalse
		\@nonetrue
	\or\or\@fulltrue\fi
}

\newif\ifchange@num
\change@numtrue
\DeclareOptionX{changecounternumbering}{
	\if\relax\detokenize{#1}\relax\fi
	\ifcase#1\change@numfalse\fi
}

\def\bm@init#1{
	\ifx#1\@@Kalpurush
    	\def\bm@scale{\@Kalpurush{1}}
    	\def\bm@wordspace{\@Kalpurush{2}}
	\else\ifx#1\@@SiyamRupali
    	\def\bm@scale{\@SiyamRupali{1}}
    	\def\bm@wordspace{\@SiyamRupali{2}}
    \else\ifx#1\@@SolaimanLipi
    	\def\bm@scale{\@SolaimanLipi{1}}
    	\def\bm@wordspace{\@SolaimanLipi{2}}
	\else
	    \def\bm@scale{MatchLowercase}
    	\def\bm@wordspace{1}
    \fi\fi\fi
}
\def\btt@init#1{
	\ifx#1\@@Kalpurush
    	\def\btt@scale{\@Kalpurush{1}}
    	\def\btt@wordspace{\@Kalpurush{3}}
	\else\ifx#1\@@SiyamRupali
    	\def\btt@scale{\@SiyamRupali{1}}
    	\def\btt@wordspace{\@SiyamRupali{3}}
    \else\ifx#1\@@SolaimanLipi
    	\def\btt@scale{\@SolaimanLipi{1}}
    	\def\btt@wordspace{\@SolaimanLipi{3}}
	\else
		\def\btt@scale{MatchLowercase}
    	\def\btt@wordspace{1.2}
    \fi\fi\fi
}

\ProcessOptionsX\relax

%From polyglossia
\ifchange@num
	\setmainlanguage[numerals=Bengali, changecounternumbering=false]{bengali}
\else
	\setmainlanguage{bengali}
\fi

\def\bengalinumber#1{\bengalidigits{\number#1}}
\def\bengalinumeral#1{\bengalinumber{\csname
c@#1\endcsame}}

\newfontfamily\bengalifont[%
	Script=Bengali,%
	Scale=\bm@scale,%
	NFSSFamily=\bm@@name,%
	WordSpace=\bm@wordspace,%
	AutoFakeSlant,
	AutoFakeBold=2.5
	]{[\bm@name]}

\newfontfamily\bengalifonttt[%
	Script=Bengali,%
	Scale=\btt@scale,%
	NFSSFamily=\btt@@name,
	WordSpace=\btt@wordspace,%
	AutoFakeSlant,
	AutoFakeBold
	]{[\btt@name]}

\newenvironment{latin}{\fontencoding{OT1}\ifx\f@family\btt@@name\fontfamily{lmtt}\else\fontfamily{lmr}\fi\selectfont}\relax

%Devanagari is required since Bangla fullstop dari ("0964) is in
%Devanagari block of Unicode
\RequirePackage[Latin, Bengali, Devanagari]{ucharclasses}
\setTransitionsForLatin{\begin{latin}}{\end{latin}}

%if feature=0 is provided no other modifications will be enabled
%However, from my personal experience, I find the following modifications to be useful.

%the default for feature option is 1, which enables the recommended modifications
\if@recom
	\RequirePackage{titlesec, amsthm, xpatch, amsfonts, amssymb, amsmath, chngcntr, enumerate}
	%adding a dot after the number in titles
	%\titlelabel{\thetitle.\enspace}
	
	%\iffalse
	%removing space before proof - for book
	\makeatletter
	\renewenvironment{proof}[1][\proofname]{\par
		\pushQED{\qed}%
		\normalfont
		\topsep0pt \partopsep0pt % no space before
		\trivlist
		\item[\hskip\labelsep
		\itshape
		#1\@addpunct{.}]\ignorespaces
	}{%
		\popQED\endtrivlist\@endpefalse

	}
	\makeatother
	%\fi 
	
	
	%making the word "proof" in proof env. bold and adding a : after it.
	\xpatchcmd{\proof}{\itshape}{\bfseries}{}{}
	%\xpatchcmd{\proof}{\@addpunct{.}}{\@addpunct{:}}{}{}
	
	
	
	
	\counterwithin{equation}{section}

	%\renewcommand\UrlFont{\fontencoding{OT1}\fontfamily{lmtt}\selectfont}

	%increases gap between lines
	\linespread{1.15}

	\def\bengaliletters#1{\expandafter\@bengali@letters #1@}
	\def\@bengali@letters#1{%
  	  \ifx @#1% terminate
      \else
        \ifcase#1ক\orখ\orগ\orঘ\orঙ\orচ\orছ\orজ\orঝ\orঞ\orট\orঠ\orড\orঢ\orণ\orত\orথ\orদ\orধ\orন\orপ\orফ\orব\orভ\orম\orয\orর\orল\orশ\orষ\orস\orহ\orৎ\orং\orঃ\orঁ\fi
        \expandafter\@bengali@letters
      \fi
    }
    \def\bengalialphabet#1{\bengaliletters{\number#1}}% Takes number
    \def\tobengalialph#1{\expandafter\bengaliletters\csname c@#1\endcsname}
    \newcounter{bengalialph}
    \setcounter{bengalialph}{1}
    \renewcommand{\thebengalialph}{\tobenglaialph{bengalialph}}
	%defining a \tobangla which converts numbers in any counter to bangla
	%\def\@banglanumber#1{\expandafter\@@banglanumber\number#1\@nil}
	%\def\@@banglanumber#1{\ifx#1\@nil
	%\else\char\numexpr#1+"09E6\relax\expandafter\@@banglanumber\fi}
	\def\tobangla#1{\expandafter\bengalinumber\csname c@#1\endcsname}
	\def\numtobangla#1{\bengalinumber#1\@nil}

	%Because polyglossia itself defines প্রমাণ as italic. I'm making it bold.
	\addto\captionsbengali{\renewcommand\proofname{\bfseries প্রমাণ}}

	%a new solution environment
	%\newenvironment{solution}[1][সমাধান]{\proof[\bfseries #1]}{\endproof}



	% \newtheoremstyle{haha}{3pt}{3pt}{}{}{\bfseries}{:}{.5em}{\thmname{#3}\thmnumber{ #2}}
		
	% \theoremstyle{haha}
	
	\theoremstyle{definition}
	\newtheorem*{solution}{সমাধান}

	



	\newtheoremstyle{custom}% name
	{3pt}% space above
	{3pt}% space below
	{\itshape}% body font
	{}% indent amount
	{\upshape\bfseries}% theorem head font
	{:}% punctuation after theorem head
	{.5em}% space after theorem head
	{}%{\thmname{#1}\thmnumber{ \normalfont#2}\thmnote{(#3)}}% theorem head spec
	
	\theoremstyle{custom}
	%\newtheorem{example}{উদাহরণ}

	%converting all the useful counters not handled by polyglossia to bangla
	\renewcommand{\theequation}{\thesection.\tobangla{equation}}
	%\renewcommand{\theexample}{\tobangla{example}}
	\renewcommand{\theenumi}{\tobangla{enumi}}
	\renewcommand{\theenumii}{\tobangla{enumii}}
	\renewcommand{\theenumiii}{\tobangla{enumiii}}
	\renewcommand{\thefootnote}{\tobangla{footnote}}
\fi

%feature=2 enabes further modifiations as follows
\if@full
	\RequirePackage{titlesec, amsthm, xpatch, amsfonts, amssymb, amsmath, enumerate, chngcntr}
	% \theoremstyle{custom}
	% \newtheorem{corollary}{\bfseries অনুসিদ্ধান্ত}[section]
	% \newtheorem{property}{\bfseries বৈশিষ্ট্য}[section]
	% \newtheorem*{hint} {\bfseries হিন্ট}
	% \renewcommand{\thecorollary}{\thesection.\tobangla{corollary}}
	% \renewcommand{\theproperty}{\thesection.\tobangla{property}}
	% \addto\captionsbengali{\renewcommand\abstractname{সারসংক্ষেপ}}
	\addto\captionsbengali{\renewcommand\bibname{\bfseries গ্রন্থসূত্র}}
	\addto\captionsbengali{\renewcommand{\figurename}{চিত্র}}
	% \newenvironment{motive}{\proof[\bfseries মোটিভেশন]}{\phantom\qedhere\endproof}
	\def\equationautorefname~#1\null{(#1)\null}
\fi
	\addto\captionsbengali{\renewcommand{\figurename}{চিত্র}}
	\addto\captionsbengali{\renewcommand{\contentsname}{সূচি}}
	\addto{\captionsbengali}{\renewcommand{\bibname}{তথ্যবিবরণী}}
\endinput