%D \module
%D   [      file=s-resent-windows, % was s-pre-09
%D        version=unknown,
%D          title=\CONTEXT\ Style File,
%D       subtitle=Presentation Environment Windows,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

\startmodule[present-windows]

%D I made this style when I had to give a presentation on the \MAPS\ bibliography
%D production for several user group meetings. This style is rather tuned for
%D combinations of examples and explanations. The colors match the \MAPS\
%D bibliography colors.

\doifelsemode {asintended} {
    \setupbodyfont[ludicaot,14.4pt]
} {
    \setupbodyfont[pagella,14.4pt]
}

%D A couple of years later, in 2001 this style was documented and made public. While
%D documenting, I also changed box building on top of overlays into the now
%D available layer positioning. So, this styles demonstrates quite some tricks.
%D
%D I'm sure that nowadays it can be done with less code but therei sno real need to
%D rewrite history.

\setuppapersize
  [S6][S6]

\setuplayout
  [topspace=0cm,
   backspace=0cm,
   header=0pt,
   footer=0pt,
   width=middle,
   height=middle]

%D Local environments can be set by using the setups commands. For downward
%D compatibility, we keep supporting the \type {\...Settings} hooks. Using local
%D environments is seldom needed.

\let\TextSettings  \empty
\let\SampleSettings\empty

\startsetups [text]   \TextSettings   \stopsetups
\startsetups [sample] \SampleSettings \stopsetups

%D The dimensions are kind of fixed.

\def\FrameWidth  {448pt}
\def\FrameHeight {348pt}
\def\FrameOffset {24pt}
\def\FrameSkip   {12pt}

%D But they {\em can} and {\em will} be changed.

\def\FrameWidth  {408pt}
\def\FrameHeight {318pt}

%D The funny values come from the $3:4$ display aspect ratio.

\definecolor[PageColor]       [s=.40]
\definecolor[TextColor]       [s=.90]
\definecolor[InteractionColor][r=.40]
\definecolor[LineColor]       [r=.60,g=.60]

%D Of course we go interactive and since we will probably open other documents, we
%D make sure that the viewer opens a new window.

\setupinteraction
  [color=InteractionColor,
   contrastcolor=LineColor,
   display=new,
   state=start]

\setupinteractionscreen
  [option=max]

%D Before we come to the real macros, we do a little bit of tuning.

\setupitemize
  [1][packed]

\setuptyping
  [blank=medium]

%D Apart from the titlepage, the page gets a simple colored background. Later we
%D will activate the background.

\setupbackgrounds
  [page]
  [backgroundcolor=PageColor]

%D Everything gets frames by a nice \METAPOST\ frame.

\defineoverlay [background] [\uniqueMPgraphic{background}]

\startuniqueMPgraphic{background}
    pickup pencircle scaled (1.5*\FrameSkip) ;
    draw OverlayBox withcolor "PageColor" ;
    pickup pencircle scaled \FrameSkip ;
    fill OverlayBox withcolor "TextColor" ;
    draw OverlayBox withcolor "LineColor" ;
\stopuniqueMPgraphic

%D We will present samples and explanation pair||wise, so we need a hyperlink that
%D skips a page. Contrary to \MKII\ we put the next button in the page background and
%D the two windows get buttons that toggle between them. This is easier.

\defineoverlay [nextpage]     [\overlaybutton{nextpage}]
\defineoverlay [previouspage] [\overlaybutton{previouspage}]
\defineoverlay [skippage]     [\overlaybutton{realpage(\number\numexpr\realpageno+2\relax)}]
\defineoverlay [samepage]     [\overlaybutton{realpage(\number\numexpr\realpageno  \relax)}]

%D Layers are normally used to position multiple content on a specific overlay. Here
%D we will use them to position only and since the samples and text will swap place,
%D we will use quite a few layers.

\defineoverlay [text]   [\composedlayer{text}]
\defineoverlay [sample] [\composedlayer{sample}]
\defineoverlay [common] [\composedlayer{common}]

%D There are three positions. When combined, the sample and text windows overlap,
%D otherwise the lone window is centered. We could have used one layer and reversed
%D the order by setting the \type {direction} parameter, but this approach is more
%D readable.

\definelayer
  [text]
  [x=\makeupwidth,
   y=\makeupheight,
   location=lt,
   hoffset=-\FrameSkip,
   voffset=-\FrameSkip]

\definelayer
  [sample]
  [hoffset=\FrameSkip,
   voffset=\FrameSkip]

\definelayer
  [common]
  [x=.5\makeupwidth,
   y=.5\makeupheight,
   location=c]

%D The topic is put in the lower right corner of the text window.

\defineoverlay [topic] [\composedlayer{topic}]

\definelayer
  [topic]
  [x=\FrameWidth,
   y=\FrameHeight,
   location=lt,
   hoffset=-\FrameOffset,
   voffset=-\FrameSkip]

%D The topic is put in a framed box. That way we can make sure that it gets a
%D background, which looks better when it covers something else. Otherwise we could
%D have stuck to:
%D
%D \starttyping
%D \def\Topic#1%
%D   {\setlayer[topic]{\color[PageColor]{\bfb\setstrut#1}}}
%D \stoptyping
%D
%D But, we go for the nice alternative:

\unexpanded\def\Topic#1%
  {\doifsomething{#1}
     {\setlayer [topic]
        {\bfb\setstrut
         \inframed
           [frame=off,
            foregroundcolor=PageColor,
            offset=0pt,
            background=color,
            backgroundcolor=TextColor]
           {#1}}}}

%D The sample as well as the explanation will be collected in a buffer. That way we
%D can reuse the content. We could have used a box instead, but can we be sure that
%D the content is not adapting itself? So, buffers we use.

\resetbuffer[sample]
\resetbuffer[text]

%D Both the sample and explanation are kind of windowed.

\defineframedtext
  [SampleText]
  [width=\FrameWidth,
   height=\FrameHeight,
   offset=\FrameOffset,
   frame=off,
   align=normal,
   strut=no,
   before=,
   after=,
   background=background]

%D We safe some keying in by combining things in one macro.

\unexpanded\def\DoSampleText#1#2#3% kind layer overlays
  {\setupframedtexts[SampleText][background={background,#3}]
   \setlayer[#2]
     {\startSampleText[none]
        \setups[#1]
        \getbuffer[#1]
      \stopSampleText}}

\unexpanded\def\StartSample{\dostartbuffer[sample][StartSample][StopSample]}
\unexpanded\def\StartText  {\dostartbuffer[text]  [StartText]  [StopText]}

%D The following definitions apply at the outer level.

\unexpanded\def\StopSample
  {\startstandardmakeup
     \DoSampleText{sample}{common}{samepage}
   \stopstandardmakeup
   \resetbuffer[sample]}

\unexpanded\def\StopText
  {\startstandardmakeup
     \DoSampleText{text}{common}{topic,samepage}
   \stopstandardmakeup
   \resetbuffer[text]}

\setupbackgrounds[page][background={color,nextpage}]
\setupbackgrounds[text][background=common]

%D When we combine sample and text, we get slightly different definitions. As you
%D can see we generate two pages. Watch how we manipulate the order of the overlays
%D and teh nature of the buttons. Here some abstraction really pays off.

\unexpanded\def\StartIdea
  {\bgroup
   \let\StopSample\relax
   \let\StopText  \relax}

\unexpanded\def\StopIdea
  {\setupbackgrounds[page][background={color,skippage}]
   \setupbackgrounds[text][background={text,sample}]
   \startstandardmakeup
     \DoSampleText{sample}{sample}{nextpage}
     \DoSampleText{text}  {text}  {topic,nextpage}
   \stopstandardmakeup
   \setupbackgrounds[page][background={color,nextpage}]
   \setupbackgrounds[text][background={sample,text}]
   \startstandardmakeup
     \DoSampleText{sample}{sample}{previouspage}
     \DoSampleText{text}  {text}  {topic,previouspage}
   \stopstandardmakeup
   \egroup}

%D The rest of the definitions takes care of the title page. Please don't steal this
%D one for your own documents.

\defineoverlay[joke] [\useMPgraphic{joke}{n=0}] % not to be changed!

\startuseMPgraphic{joke}{n}
    StartPage ;
        path p, q ; numeric w ; pair xy ;
        set_grid(OverlayWidth,OverlayHeight,OverlayWidth/8,OverlayHeight/8) ;
        if \MPvar{n}=1 :
            p := fulldiamond ; fill Page withcolor \MPcolor{TextColor} ;
        else :
            p := fullsquare  ; fill Page withcolor \MPcolor{PageColor} ;
        fi ;
        forever :
            xy := center Page randomized (OverlayWidth,OverlayHeight) ;
            if new_on_grid(xpart xy, ypart xy) :
                q := (p xyscaled (OverlayWidth/5,OverlayHeight/5))
                    randomized (\FrameSkip,\FrameSkip)
                    shifted xy ;
                w := (\FrameSkip) randomized (\FrameSkip/2) ;
                draw q withcolor \MPcolor{PageColor} withpen pencircle scaled (1.5w) ;
                fill q withcolor \MPcolor{TextColor} ;
                draw q withcolor \MPcolor{LineColor} withpen pencircle scaled (   w) ;
            fi ;
            exitif grid_full ;
        endfor ;
    StopPage ;
\stopuseMPgraphic

\defineoverlay[fuzzy][\useMPgraphic{fuzzy}]

\startuseMPgraphic{fuzzy}
    path p ; numeric w ;
    p := (fullsquare xyscaled (OverlayWidth,OverlayHeight))
            randomized (\FrameSkip,\FrameSkip) ;
    w := (\FrameSkip) randomized (\FrameSkip/2) ;
    draw p withcolor \MPcolor{PageColor} withpen pencircle scaled (1.5w) ;
    fill p withcolor \MPcolor{TextColor} ;
    draw p withcolor \MPcolor{LineColor} withpen pencircle scaled (   w) ;
\stopuseMPgraphic

%D This time we use a fit window, but with a slightly randomized frame, our
%D trademark so to say.

\unexpanded\def\StartTitlePage
  {\bgroup
   \setupbackgrounds[page][background={joke,nextpage}]
   \startstandardmakeup
   \switchtobodyfont[big]
   \setupframedtexts
     [SampleText]
     [background=fuzzy,
      foregroundcolor=PageColor,
      width=fit,
      height=fit,
      align=middle]
   \startSampleText[middle]
   \bfd\setupinterlinespace
   \enforced\protected\def\\{\bfb\setupinterlinespace\vfil\enforced\protected\def\\{\vfil}}}

\unexpanded\def\StopTitlePage
  {\stopSampleText
   \stopstandardmakeup
   \egroup}

\unexpanded\def\TitlePage#1%
  {\StartTitlePage#1\StopTitlePage}

%D Let's nil some error prone presentation macros.

\let\Subject  \Topic
\let\Topics   \gobbleoneargument
\let\Subjects \relax

%D We will avoid \quote {overfull} messages.

\dontcomplain

\stopmodule

\continueifinputfile{s-present-windows.mkiv}

\usemodule[present-common]

\inputpresentationfile{examples/present-windows-001.tex}