vertically center all slides in ConTeXt with minimal setups

Question

I would like to emulate beamer's centred framed behaviour in my ConTeXt presentation. Thanks to this post, I figured out how to have my (sub)section titles centred. I am also using a makeup for my main title. My main text wasn't vertically centred however. Today, I realized I could use a custom framed environment.

Here is how I get my vertically centred presentations now (all the setups are in an environment, I past the relevant item in the MWE for convenience):

\setuppapersize[S5]
\setupbodyfont[18pt]
\setuplayout[topspace=1cm,backspace=1.5cm,
   width=14.5cm,height=11cm,%margin=0cm,
   footer=0cm,header=0cm]    
\definelayout[titre][topspace=0cm,backspace=1.5cm,
   width=15cm,height=11cm,
   footer=0cm,header=0cm]
\definemakeup[titre]     
\setuphead[title][
   alternative=middle,%titre centré sur la ligne
   before={\leavevmode \vfill},after={\vfill \page},
   style=\tfd]
\setuphead[section][align=lohi,
   before={\page\leavevmode \vfill},after={\vfill},
   style=\tfc,conversion=I,
   numbercommand=\groupedcommand{}{~)},%) après le numéro
   align={flushleft, nothyphenated, verytolerant}]    
\defineframedtext
     [Diapo]
     [frame=no,
     before={\page\leavevmode\vfill},after={\vfill}]

\starttext
\startmakeup[titre]
\starttitle[title={Un test}]
\stopmakeup

\startsection[title={Bonjour}]
  \startDiapo
      Hello world!
   \stopDiapo
\stopsection
\stoptitle
\stoptext 

Here is my question : how can I minimize those setups? Especially:

• is there any way to get my texts centred without framing them (\start/stopDiapo)?
• I couldn't find any global command that gives a vertically centred layout. Is there a way to do it?

Answer 1

Makeup environment

The best method to center the content of each frame is the use of a makeup environment. With the top and bottom you can control the vertical alignment of the text and with the align key you can change the horizontal alignment.

\setuppapersize [S3] [S3,doublewide]
\showframe [page]
\setuparranging [2SIDE]
\starttext
First page
\startstandardmakeup [align=middle,pagestate=start,headerstate=start]
Second page
\stopstandardmakeup
\stoptext

Section headers

When you use the environment form of section header get additional keys to insert commands before and after the content of each section.

When you have a header without content (e.g. for the title page) you can use the regular form and pass the title as argument to the command.

\setuppapersize [S3] [S3,doublewide]
\showframe [page]
\setuparranging [2SIDE]
\define[1]\ShowKey
  {\par
   \leftaligned{\tttf [key: #1]}%
   \par}
\setuphead
  [subject]
  [       before=\ShowKey{before},
           after=\ShowKey{after},
   beforesection=\ShowKey{beforesection},
   insidesection=\ShowKey{insidesection},
    aftersection=\ShowKey{aftersection}]
\setupheader [state=stop]
\starttext
\subject {First subject}
\page
\startsubject [title={Second subject}]
Subject content
\stopsubject
\stoptext

Combination of both mechanism

You can combine the makeup environment with the environment form of section headers and use the insidesection and aftersection keys to center the content of each section.

\setuppapersize [S3]
\definehead [frametitle]   [title]
\definehead [framesection] [section]
\definemakeup
  [section]
  [pagestate=start,
   align=middle]
\definemakeup
  [frame]
  [pagestate=start,
   align=middle]
\setuphead
  [frametitle]
  [align=middle,
   before=\startsectionmakeup,
   after=\stopsectionmakeup]
\setuphead
  [framesection]
  [align=middle,
   before=\startsectionmakeup,
   after=\stopsectionmakeup,
   insidesection=\startframemakeup,
   aftersection=\stopframemakeup]
\starttext
\frametitle{Un test}
\startframesection[title={Bonjour}]
  Hello world!
\stopframesection
\stoptext