% \iffalse meta-comment
%
% Copyright 2006
% Sergio Callegari <sergio.callegari@gmail.com>
%
% ---------------------------------------------
% This file is part of the draftwatermark package,
% a contribution to the LaTeX2e system.
% ---------------------------------------------
%
% It may be distributed and/or modified under the conditions of the
% LaTeX Project Public License, either version 1.3 of this licence, or
% any later version. The latest version of this license is at
% http://www.latex-project.org/lppl.txt and version 1.3 is part
% of all distributions of LaTeX version 2003/06/01 or later.
%
% This work has the LPPL maintenance status "author-maintained".
%
% This program consists of the files listed in the README file
% included in the package.
%
%<*driver>
\documentclass{ltxdoc}
\usepackage{mathptmx, helvet, courier}
\EnableCrossrefs
\DoNotIndex{\def,\gdef,\let,\NeedsTeXFormat,\newcommand}
\DoNotIndex{\ProvidesPackage,\endinput}
\DoNotIndex{\box,\dp,\fontsize,\ifx,\else,\fi}
\DoNotIndex{\hbox,\hss,\makebox,\moveleft,\newif,\newlength}
\DoNotIndex{\ProcessOptions,\vbox,\vss,\z@}
\CodelineIndex
\RecordChanges
\begin{document}
  \DocInput{draftwatermark.dtx}
\end{document}
%</driver>
%
% \fi
%
% \CheckSum{96}
%
% \def\filename{draftwatermark.dtx}
% \def\fileversion{1.0}
% \def\filedate{2006/06/30}
% \def\docdate{2006/06/30}
%
% \newcommand*{\Lpack}[1]{\textsf {#1}}           ^^A typeset a package
% \newcommand*{\Lopt}[1]{\textsf {#1}}            ^^A typeset an option
% \newcommand*{\file}[1]{\texttt {#1}}            ^^A typeset a file
% \newcommand*{\Lcount}[1]{\textsl {\small#1}}    ^^A typeset a counter
% \newcommand*{\pstyle}[1]{\textsl {#1}}          ^^A typeset a pagestyle
% \newcommand*{\Lenv}[1]{\texttt {#1}}            ^^A typeset an environment
%
% \title{The \Lpack{draftwatermark} package\thanks{This file
%     (\texttt{\filename}) has version number \fileversion, last
%     revised \filedate.}}
%
% \author{%
%   Sergio Callegari\thanks{Sergio Callegari can be reached at
%       \texttt{sergio.callegar at gmail dot com}}} 
%
% \date{\docdate}
%
% \maketitle
%
% \begin{abstract}
%   The \Lpack{draftwatermark} package extends \LaTeX\ providing a
%   means to add a textual, light gray watermark on every page or on
%   the first page of a document. Typical usage may consist in writing
%   words such as \emph{DRAFT} or \emph{CONFIDENTIAL} across document
%   pages. The package may remind in some sense \Lpack{draftcopy} by
%   Dr. Juergen Vollmer, but its implementation is much lighter (as
%   the reduced code footprint shows) and does not rely on postscript
%   specials, making the package fully compatible with pdf\LaTeX. The
%   package depends on \Lpack{everypage} by the same author.
% \end{abstract}
% 
% \section{Introduction}
% 
% This program extends \LaTeX\ providing a means to add a textual,
% light gray watermark on every page or on the first page of a
% document. Typical usage may consist in writing words such as
% \emph{DRAFT} or \emph{CONFIDENTIAL} across document pages. Typical
% usage may consist in writing words such as \emph{DRAFT} or
% \emph{CONFIDENTIAL} across document pages. The package may remind in
% some sense \Lpack{draftcopy} by Dr. Juergen Vollmer, but its
% implementation differs by a few points:
% \begin{enumerate}
% \item Code footprint is much, much smaller (about one order of
%   magnitude smaller), although this does not mean much on modern
%   computers.
% \item There is no use of Postscript specials or other
%   driver-dependent tricks, so the package should be compatible with
%   any output driver and with pdf\LaTeX\ in particular. Lack of
%   compatibility with pdf\LaTeX\ in these days is the biggest pitfall
%   of \Lpack{draftcopy} and was the first motivation for writing
%   \Lpack{draftwatermark}.
% \item Reduced code footprint comes at some price with regards to
% features. Many features of \Lpack{draftcopy} are not supported here,
% most notably \Lpack{draftwatermark} has:
% \begin{itemize}
% \item No automatic selection of the watermark text to use, depending on
%   the language, using translations of the word ``DRAFT''. However,
%   this is no big loss, since there is a possibility to set the text
%   to use explicitly, and this leaves the freedom to chose whatever
%   text one happens to prefer, including things that have nothing to
%   do with the word ``DRAFT'' (e.g., ``CONFIDENTIAL'', ``FOR YOUR
%   EYES ONLY'', etc.).
% \item No possibility to put the watermark at the bottom of the page.
% Watermarks are placed at the center of the page.
% \item No possibility to selectively activate or disactivate
% operation depending on the global draft and final options.
% No possibility to watermark only the first \emph{two} pages of a
% document. However, it is possible to watermark only the first.
% \end{itemize}
% Other features available as options in \Lpack{draftcopy} (e.g., the
% possibility of time-stamping the watermark text) can qbe obtained
% working on the watermark text itself.
% \item Dependence on the \Lpack{everypage} package by the same
% author.
% \end{enumerate}
% 
% \section{User interface}
% When loaded, \Lpack{draftwatermark} sets up a number of defaults
% (detailed later and modifiable by specific commands) and immediately
% becomes active. If loaded as
% \begin{quote}
% |\usepackage{draftwatermark}|
% \end{quote}
% the package sets up itself to put a background text on every
% page. Alternatively, if loaded as
% \begin{quote}
% |\usepackage[firstpage]{draftwatermark}|
% \end{quote}
% the package sets up itself to put a background text only on the
% first page.
%
% \subsection{Default behavior and commands to modify it}
% The package defaults are illustrated in table~\ref{tbl:defaults}.
%
% \begin{table}[ht]
%   \begin{center}
%     \DeleteShortVerb{\|}
%     \begin{tabular}{|p{0.6\linewidth}|c|}
%       \hline
%       \MakeShortVerb{\|}       
%       Behavior & Default value\\
%       \hline\hline
%       Angle at which the watermark text is drawn & 45°\\
%       Lightness of the watermark text (1=white, 0=black) & 0.8\\
%       Font size of the watermark text & 5$\;$cm\\
%       Scaling of the watermark text & 1.2\\
%       Watermark text & DRAFT\\
%       \hline
%     \end{tabular}
%   \end{center}
%   \caption{Package defaults.}
%   \label{tbl:defaults}
% \end{table}
%
% With reference to the defaults, note that:
% \begin{enumerate}
% \item the watermark text is always in gray;
% \item the watermark font size cannot exceed a maximum value that is
%   about 5$\;$cm.
% \item the watermark scale can be any value. Using the default, the
% word ``DRAFT'' at 45° uses up all the space on an A4 paper. To have
% a good looking large text, it is better to enlarge the font size as
% much as possibile, rather than using a small font size and pumping
% up the scale.
% \end{enumerate}
%
% \DescribeMacro{\SetWatermarkAngle}
% \DescribeMacro{\SetWatermarkLightness}
% \DescribeMacro{\SetWatermarkFontSize}
% \DescribeMacro{\SetWatermarkScale}
% \DescribeMacro{\SetWatermarkText}
% Table~\ref{tbl:commands} illustrates the commands used to modify the
% package behaviour. Note that there is exactly one command per
% function and that every command takes a single argument.
%
% \begin{table}[ht]
%   \begin{center}
%     \DeleteShortVerb{\|}
%     \begin{tabular}{|p{0.4\linewidth}|l|}
%       \hline
%       \MakeShortVerb{\|}
%       Behavior & Command affecting it\\
%       \hline\hline
%       Angle at which the watermark text is drawn &
%       |\SetWatermarkAngle{|\meta{real}|}|\\
%       Lightness of the watermark text (1=white, 0=black) &
%       |\SetWatermarkLightness{|\meta{real}|}|\\
%       Font size of the watermark text &
%       |\SetWatermarkFontSize{|\meta{lenght}|}|\\
%       Scaling of the watermark text &
%       |\SetWatermarkScale{|\meta{real}|}|\\
%       Watermark text &
%       |\SetWatermarkScale{|\meta{text}|}|\\
%       \hline
%     \end{tabular}
%   \end{center}
%   \caption{Commands affecting the package behavior.}
%   \label{tbl:commands}
% \end{table}
%
% Observe that the |\SetWatermarkFontSize| command takes a lenght
% rather than a simple number. Also observe that multiline textual
% watermarks can easily be obtained by the |\shortstack| command and
% that there is the possibility of using an image rather than a text
% (e.g., a ``caution, work in progress'' sign, etc.). 
%
% Note that once the package is loaded, there is no way to stop it.
% In order to have textual watermarks that appear only when
% specific conditions are met, conditionals must be included in the
% watermarks.
% 
% Eventually consider that no special assumption is made on the
% \LaTeX\ output driver, so \Lpack{draftwatermark} should work equally
% well with \LaTeX\ and pdf\LaTeX. Furthermore, the package should
% work equally well with the dvi, dvips, etc.\@ output drivers.
% Obviously, the final compatibility with the different output drivers
% depends on the actual code that is placed in the textual watermark.
% 
% \StopEventually {}
% 
% \section{Implementation}
%
% Announce the name and version of the package, which requires
% \LaTeXe.
%    \begin{macrocode}
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{draftwatermark}%
  [2006/06/30 1.0 Put a gray textual watermark on document pages]
%    \end{macrocode}
%
% Require the needed packages. Note that if these are pre-loaded
% before loading \Lpack{draftwatermark}, using suitable options to
% preset behavior for a desired output driver, this is used also
% here.
%    \begin{macrocode}
\RequirePackage{everypage}
\RequirePackage{graphicx}
\RequirePackage{color}
%    \end{macrocode}
%
% \begin{macro}{\if@sc@wm@first}
% Set up the conditional to store whether a watermark is needed only
% on the first page or everywhere.
%    \begin{macrocode}
\newif\if@sc@wm@first
\@sc@wm@firstfalse
%    \end{macrocode}
% \end{macro}
% 
% Declare the package options.
%    \begin{macrocode}
\DeclareOption{firstpage}{%
  \@sc@wm@firsttrue}
\ProcessOptions
%    \end{macrocode}
%
% \begin{macro}{\sc@wm@angle}
% \begin{macro}{\sc@wm@lightness}
% \begin{macro}{\sc@wm@scale}
% \begin{macro}{\sc@wm@fontsize}
% \begin{macro}{\sc@wm@text}
% Set up the package defaults.
%    \begin{macrocode}
\newlength\sc@wm@fontsize
%% defaults
\def\sc@wm@angle{45}
\def\sc@wm@lightness{0.8}
\def\sc@wm@scale{1}
\setlength\sc@wm@fontsize{5cm}
\def\sc@wm@text{DRAFT}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\SetWatermarkAngle}
% \begin{macro}{\SetWatermarkLightness}
% \begin{macro}{\SetWatermarkFontSize}
% \begin{macro}{\SetWatermarkScale}
% \begin{macro}{\SetWatermarkText}
% Set up the commands to modify the behavior.
%    \begin{macrocode}
\newcommand\SetWatermarkAngle[1]{%
  \def\sc@wm@angle{#1}}
\newcommand\SetWatermarkLightness[1]{%
  \def\sc@wm@lightness{#1}}
\newcommand\SetWatermarkFontSize[1]{%
  \setlength\sc@wm@fontsize{#1}}
\newcommand\SetWatermarkScale[1]{%
  \def\sc@wm@scale{#1}}
\newcommand\SetWatermarkText[1]{%
  \def\sc@wm@text{#1}}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
%\begin{macro}{\sc@watermark}
% The command to draw the watermark\ldots This assumes an origin in
% the left top corner of the page (and also assumes that |\paperwidth|
% and |\paperheight| are set correctly. There is no need to worry
% about the horizontal and vertical size that is taken by the
% watermark object. Note that this is typically a text, but
% |\sc@wm@text| may well contain other material, e.g.\@ an
% |\includegraphics| directive.
%    \begin{macrocode}
\newcommand\sc@watermark{%
  \setlength{\@tempdimb}{.5\paperwidth}%
  \setlength{\@tempdimc}{-.5\paperheight}%
  \put(\strip@pt\@tempdimb,\strip@pt\@tempdimc){%
    \makebox(0,0){\rotatebox{\sc@wm@angle}{%
        \scalebox{\sc@wm@scale}{%
        \textcolor[gray]{\sc@wm@lightness}{
          \fontsize{\sc@wm@fontsize}{1.2\sc@wm@fontsize}
          \selectfont
          \sc@wm@text}}}}}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\sc@wm@print}
% The command to actually \emph{print} the watermark. It is assumed
% that this is called before any other material is shipped to the
% page. As such, the origin here is the page origin in Knuthian sense
% (1 inch down, 1 inch right from the top left corner of the
% page\ldots First of all, this is changed to the proper top left
% corner of the page. 
%    \begin{macrocode}
\newcommand\sc@wm@print[1]{%
  \setbox\@tempboxa\vbox to \z@{%
    \vskip -1in \moveleft 1in \vbox{%
      \hbox to \z@{%
        #1\hss}}\vss}
  \dp\@tempboxa\z@
  \box\@tempboxa}
%    \end{macrocode}
% \end{macro}
%
% Eventually, set up the |\sc@wm@print| command to be called when
% needed, using the appropriate \Lpack{everypage} hook.
%    \begin{macrocode}
\if@sc@wm@first
\AddThispageHook{\sc@wm@print{\sc@watermark}}
\else
\AddEverypageHook{\sc@wm@print{\sc@watermark}}
\fi
\endinput
%    \end{macrocode}
%
% \Finale
% \PrintIndex
%
%% \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         \~}
\endinput

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