\environment interaction-style

\startcomponent interaction-widgets

\startchapter[title={Widgets}]

    {\em This chapter will discuss forms and special buttons.}

\stopchapter

\stopcomponent

% Below comes from the old widgets manual:

\def\fillinfield#1{}

% \useJSscripts[fld]
% \setupinteraction[state=start,closeaction=ForgetAll]

\section{Fill||in fields}

Fields come in many disguises. Currently \CONTEXT\ supports
the field types provided by \PDF, which in turn are derived
from \HTML. Being a static format and not a programming
language, \PDF\ only provides the interface. Entering data
is up to the viewer and validation to the built in
\JAVASCRIPT\ interpreter. The next paragraph shows an
application.

\startbuffer
A few years back, \TEX\ could only produce \fillinfield [dvi]
{\DVI} output, but nowadays, thanks to \fillinfield {Han The
Thanh}, we can also directly produce \fillinfield [pdf] {\PDF}!
Nice eh? Actually, while the first field module was prototyped
in \ACROBAT, the current implementation was debugged in
\fillinfield [pdfTeX] {\PDFTEX}. Field support in \fillinfield
[ConTeXt] {\CONTEXT} is rather advanced and complete and all
kind of fields are supported. One can hook in appearances, and
validation \fillinfield [JavaScripts] {\JAVASCRIPT}'s. Fields
can be cloned and copied, where the latter saves some space. By
using \fillinfield {objects} when suited, this module saves
space anyway.
\stopbuffer

\getbuffer

This paragraph is entered in the source file as:

\typebuffer

I leave it to the imagination of the user how
\type{\fillinfield} is implemented, but trust me, the
definition is rather simple and is based on the macros
mentioned below.

Because I envision documents with many thousands of fields,
think for instance of tutorials, I rather early decided to
split the definition from the setup. Due to the fact that
while typesetting a field upto three independant instances
of \type{\framed} are called, we would end up with about
150~hash entries per field, while in the current
implementation we only need a few. Each field can inherit
its specific settings from the setup group it belongs to.

Let's start with an example of a {\em radio} field. In fact
this is a collection of fields. Such a field is defined
with:

\startbuffer
\definefield
  [Logos] [radio] [LogoSetup]
  [ConTeXt,PPCHTEX,TeXUtil] [PPCHTEX]
\stopbuffer

\typebuffer

\getbuffer

Here the fourth argument specifies the subfields and the
last argument tells which one to use as default. We have to
define the subfields separately:

\startbuffer
\definesubfield [ConTeXt] [] [ConTeXtLogo]
\definesubfield [PPCHTEX] [] [PPCHTEXLogo]
\definesubfield [TeXUtil] [] [TeXUtilLogo]
\stopbuffer

\typebuffer

\getbuffer

The second argument specifies the setup. In this example
the setup (\type {LogoSetup}) is inherited from the main
field. The third arguments tells \CONTEXT\ how the fields
look like when turned on. These appearances are to be
defined as symbols:

\startbuffer
\definesymbol [ConTeXtLogo] [{\externalfigure[mp-cont.502]}]
\definesymbol [PPCHTEXLogo] [{\externalfigure[mp-cont.503]}]
\definesymbol [TeXUtilLogo] [{\externalfigure[mp-cont.504]}]
\stopbuffer

\typebuffer

\getbuffer

Before we typeset the fields, we specify some settings to use:

\startbuffer
\setupfield [LogoSetup]
  [width=4cm,
   height=4cm,
   frame=off,
   background=screen]
\stopbuffer

\typebuffer

\getbuffer

Finally we can typeset the fields:

\startbuffer
\hbox to \hsize
  {\hss\field[ConTeXt]\hss\field[PPCHTEX]\hss\field[TeXUtil]\hss}
\stopbuffer

\typebuffer

This shows up as:

\startbaselinecorrection
\getbuffer
\stopbaselinecorrection

An important characteristic of field is cloning cq.\
copying, as demonstrated below:

% \tracefieldstrue

\startbuffer[symbol]
\definesymbol [yes-a] [$\times$]
\definesymbol [yes-b] [$\star$]
\definesymbol [nop-a] [$\bullet$]
\definesymbol [nop-b] [$-$]
\stopbuffer

\getbuffer[symbol]

\startbuffer[define]
\definefield [example-1] [radio] [setup 1] [ex-a,ex-b,ex-c] [ex-c]
\definesubfield [ex-a,ex-b,ex-c] [setup 1] [yes-a,nop-a]
\stopbuffer

\getbuffer[define]

\startbuffer[clone]
\clonefield [ex-a] [ex-p] [setup 2] [yes-b,nop-b]
\clonefield [ex-b] [ex-q] [setup 2] [yes-b,nop-b]
\clonefield [ex-c] [ex-r] [setup 2] [yes-b,nop-b]
\stopbuffer

\getbuffer[clone]

\startbuffer[copy]
\copyfield [ex-a] [ex-x]
\copyfield [ex-b] [ex-y]
\copyfield [ex-c] [ex-z]
\stopbuffer

\getbuffer[copy]

\startbuffer[setup]
\setupfield [setup 1] [width=1cm,height=1cm,framecolor=red]
\setupfield [setup 2] [width=.75cm,height=.75cm]
\stopbuffer

\getbuffer[setup]

\startbuffer[field]
\hbox to \hsize
  {\field[ex-a]\hfil\field[ex-b]\hfil\field[ex-c]\hfil\hfil
   \field[ex-p]\hfil\field[ex-q]\hfil\field[ex-r]\hfil\hfil
   \field[ex-x]\hfil\field[ex-y]\hfil\field[ex-z]}
\stopbuffer

\startbaselinecorrection \getbuffer[field] \stopbaselinecorrection

The next table shows the relations between these fields of type radio:

\startbaselinecorrection
\showfields
\stopbaselinecorrection

This table is generated by \type {\showfields} and can be
used to check the relations between fields, but only when
we have set \type {\tracefieldstrue}. Radio fields have the
most complicated relationships of fields, due to the fact
that only one of them can be activated (on). By saying
\type {\logfields} one can write the current field
descriptions to the file \type {fields.log}.

Here we used some \TEX\ mathematical symbols. These are
functional but sort of dull, so later we will define a more
suitable visualization.

\typebuffer[symbol]

The parent fields were defined by:

\typebuffer[define]

and the clones, which can have their own appearance, by:

\typebuffer[clone]

The copies are defined using:

\typebuffer[copy]

using the setups

\typebuffer[setup]

Finally all these fields are called using \type {\field}:

\typebuffer[field]

Now we will define a so called {\em check} field. This
field looks like a radio field but is independant of
others. First we define some suitable symbols:

\startbuffer
\definesymbol [yes] [{\externalfigure[mp-cont.502]}]
\definesymbol [no]  []
\stopbuffer

\getbuffer

\typebuffer

A check field is defined as:

\startbuffer
\definefield [check-me] [check] [setup 3] [yes,no] [no]
\stopbuffer

\getbuffer

\typebuffer

This time we say \type{\field[check-me]} and get:

\startbuffer
\setupfield
  [setup 3]
  [width=2cm, height=2cm,
   rulethickness=3pt, corner=round, framecolor=red]
\stopbuffer

\getbuffer

\startlinecorrection
\hbox to \hsize{\hss\field[check-me]\hss}
\stoplinecorrection

As setup we used:

\typebuffer

We already saw an example of a {\em line} field. By default
such a line field looks like:

\startbuffer[define]
\definefield [Email] [line] [ShortLine] [] [pragma@wxs.nl]
\stopbuffer

\getbuffer[define]

\startbuffer[field]
\field [Email] [your email]
\stopbuffer

\startbaselinecorrection \getbuffer[field] \stopbaselinecorrection

We defined this field as:

\typebuffer[define]

and called it using a second, optional, argument:

\typebuffer[field]

As shown, we can influence the way such a field is typeset.
It makes for instance sense to use a monospaced typeface
and limit the height. When we set up a field, apart from
the setup class we pass some general characteristics, and
three more detailed definitions, concerning the
surrounding, the label and the field itself.

\startbuffer
\setupfield
  [ShortLine]
  [label,frame,horizontal]
  [offset=4pt,height=fit,framecolor=green,
   background=screen,backgroundscreen=.80]
  [height=18pt,width=80pt,align=middle,
   background=screen,backgroundscreen=.90,frame=off]
  [height=18pt,width=80pt,color=red,align=right,style=type,
   background=screen,backgroundscreen=.90,frame=off]
\stopbuffer

\typebuffer

So now we get:

\getbuffer

\startbuffer[mainmail]
\definemainfield [MainMail] [line] [ShortLine] [] [pragma@wxs.nl]
\stopbuffer

\getbuffer[mainmail]

\startlinecorrection
\field [MainMail] [your email]
\stoplinecorrection

Such rather long definitions can be more sparse when we set
up all fields at once, like:

\startbuffer
\setupfields
  [label,frame,horizontal]
  [offset=4pt,height=fit,framecolor=green,
   background=screen,backgroundscreen=.80]
  [height=18pt,width=80pt,
   background=screen,backgroundscreen=.90,frame=off]
  [height=18pt,width=80pt,color=red,align=middle,
   background=screen,backgroundscreen=.90,frame=off]
\stopbuffer

\typebuffer

So given that we have defined field \type {MainMail} we can
say:

\startbuffer[MP]
\startuniqueMPgraphic{button}
  path p ; p := fullcircle xyscaled (OverlayWidth,OverlayHeight) ;
  fill p withcolor (.8,.8,.8) ;
  draw p withcolor OverlayColor withpen pencircle scaled 3 ;
\stopuniqueMPgraphic

\defineoverlay [normalbutton] [\uniqueMPgraphic{button}]
\stopbuffer

\getbuffer[MP]

\startbuffer
\setupfield [LeftLine]
  [background=normalbutton, backgroundcolor=darkgreen,
   offset=2ex, height=7ex, width=.25\hsize,
   style=type, frame=off, align=left]
\setupfield [MiddleLine]
  [background=normalbutton, backgroundcolor=darkgreen,
   offset=2ex, height=7ex, width=.25\hsize,
   style=type, frame=off, align=middle]
\setupfield [RightLine]
  [background=normalbutton, backgroundcolor=darkgreen,
   offset=2ex, height=7ex, width=.25\hsize,
   style=type, frame=off, align=right]

\clonefield [MainMail] [LeftMail]   [LeftLine]
\clonefield [MainMail] [MiddleMail] [MiddleLine]
\clonefield [MainMail] [RightMail]  [RightLine]
\stopbuffer

\typebuffer

\getbuffer

We get get three connected fields:

\startlinecorrection
\hbox to \hsize
  {\field[LeftMail]\hss\field[MiddleMail]\hss\field[RightMail]}
\stoplinecorrection

(Keep in mind that in \CONTEXT\ left aligned comes down to
using \type {\raggedleft}, which can be confusing, but
history cannot be replayed.)

By the way, this shape was generated by \METAPOST\ using
the overlay mechanism:

\typebuffer[MP]

Due to the fact that a field can have several modes (loner,
parent, clone or copy), one cannot define a clone or copy
when the parent field is already typeset. When one knows in
advance that there will be clones or copies, one should
use:

\typebuffer[mainmail]

Now we can define copies, clones and even fields with the
same name, also when the original already is typeset. Use
\type {\showfields} to check the status of fields. When in
this table the mode is typeset slanted, the field is not
yet typeset.

The values set up with \type {\setupfield} are inherited by
all following setup commands. One can reset these default
values by:

\startbuffer
\setupfields[reset]
\stopbuffer

\typebuffer

\getbuffer

When we want more than one line, we use a {\em text} field.
Like the previous fields, text must be entered in the
viewer specific encoding, in our case, \PDF\ document
encoding. To free users from thinking of encoding,
\CONTEXT\ provides a way to force at least the accented
glyphs into a text field in a for \TEX\ users familiar way:

\setupfields
  [horizontal]
  [offset=4pt,height=fit,framecolor=green,
   background=screen,backgroundscreen=.80]
  [height=18pt,width=80pt,
   background=screen,backgroundscreen=.90,frame=off]
  [height=18pt,width=80pt,color=red,align=middle,
   background=screen,backgroundscreen=.90,frame=off]

\definefield
  [SomeField] [text] [TextSetup]
  [hi there, try \string\\ \string " e or
   \string\\ \string~ n to get \"e or \~n]

\setupfield
  [TextSetup]
  [label,frame,horizontal][framecolor=green][]
  [height=80pt,width=240pt,style=\sl,align=middle,
   enterregion=JS(Initialize_TeX_Key),
   afterkey=JS(Convert_TeX_Key),
   validate=JS(Convert_TeX_String)]

\startbaselinecorrection
\field[SomeField][Just Some Text]
\stopbaselinecorrection

Now, how is this done? Defining the field is not that hard:

\starttyping
\definefield [SomeField] [text] [TextSetup] [default text]
\stoptyping

The conversion is taken care of by a \JAVASCRIPT's. We can assign such
scripts to mouse and keyboard events, like in:

\starttyping
\setupfield
  [TextSetup][...][...][...]
  [....,
   regionin=JS(Initialize_TeX_Key),
   afterkey=JS(Convert_TeX_Key),
   validate=JS(Convert_TeX_String)]
\stoptyping

The main reason for using the \type{JS(...)} method here is
that this permits future extensions and looks familiar at
the same time. Depending on the assignments, one can
convert after each keypress and|/|or after all text is
entered.

\startbuffer
\definefield
  [Ugly] [choice] [UglySetup]
  [ugly,awful,bad] [ugly]
\setupfield
  [UglySetup]
  [width=6em,
   height=1.2\lineheight,
   location=low]
\stopbuffer

\getbuffer

We've arrived at another class of fields: {\em choice},
{\em pop||up} and {\em combo} fields. All those are menu
based (and \vbox{\field[Ugly]}). This in||line menu was
defined as:

\typebuffer

\startbuffer
\definefield
  [Ugly2] [popup] [UglySetup]
  [ugly,awful,bad] [ugly]
\definefield
  [Ugly3] [combo] [UglySetup]
  [ugly,{AWFUL=>awful},bad] [ugly]
\stopbuffer

\getbuffer

Pop||up fields look like: \vbox{\field[Ugly2]} and combo
fields permit the user to enter his or her own option:
\vbox{\field[Ugly3]}. The amount of typographic control
over these three type of fields is minimal, but one can
specify what string to show and what string results:

\typebuffer

Here \type{AWFUL} is shown and when selected becomes the
choice \type{awful}. Just in case one wonders why we use
\type{=>}, well, it just looks better and the direction
shows what value will be output.

\startbuffer[uglies]
\definefieldset [AllUglies] [Ugly, Ugly2, Ugly3]
\stopbuffer

\getbuffer[uglies]

\startbuffer
One can for instance \goto {reset the form} [ResetForm] or
\goto {part of the form} [ResetForm{AllUglies}]. This last
sentence was typed in as:
\stopbuffer

A special case of the check type field is a pure {\em push}
field. Such a field has no export value and has only use as
a pure interactive element. For the moment, let's forget
about that one.

Before we demonstrate our last type of fields and show some
more tricky things, we need to discuss what to do with the
information provided by filling in the fields. There are
several actions available related to fields.

\getbuffer

\typebuffer

Hereby \type {AllUglies} is a set of fields to be defined
on forehand, using

\typebuffer[uglies]

In a similar way one can \goto {submit some or all fields}
[SubmitForm] using the \type {SubmitForm} directive. This
action optionally can take two arguments, the first being
the destination, the second a list of fields to submit, for
instance:

\starttyping
\button{submit}[SubmitForm{mailto::pragma@wxs.nl,AllUglies}]
\stoptyping

Once the fields are submitted (or saved in a file), we can
convert the resulting \FDF\ file into something \TEX\ with
the perl program \type{fdf2tex}. One can use \type
{\ShowFDFFields{filename}} to typeset the values. If you do
not want to run the \PERL\ converter from within \TEX, say
\type {\runFDFconverterfalse}. In that case, the (stil)
less robust \TEX\ based converter will be used.

I already demonstrated how to attach scripts to events, but
how about changing the appearance of the button itself?
Consider the next definitions:

\startbuffer
\definesymbol [my-y] [$\times$]
\definesymbol [my-r] [?]
\definesymbol [my-d] [!]

\definefield
  [my-check] [check] [my-setup]
  [{my-y,my-r,my-d},{,my-r,my-d}]
\stopbuffer

\typebuffer

\getbuffer

Here we omitted the default value, which always is {\em no}
by default. The setup can look like this:

\startbuffer
\setupfield
  [my-setup]
  [width=1.5cm, height=1.5cm,
   frame=on, framecolor=red, rulethickness=1pt,
   backgroundoffset=2pt, background=screen, backgroundscreen=.85]
\stopbuffer

\typebuffer

\getbuffer

Now when this field shows up, watch what happens when the
mouse enters the region and what when we click.

\startbaselinecorrection
\hbox to \hsize{\hss\field[my-check]\hss}
\stopbaselinecorrection

So, when instead of something \type{[yes,no]} we give
triplets, the second element of such a triplet declares the
roll||over appearance and the third one the push||down
appearance. The braces are needed!

One application of appearances is to provide help or
additional information. Consider the next definition:

\startbuffer
\definefield [Help] [check] [HelpSetup] [helpinfo] [helpinfo]
\stopbuffer

\typebuffer

\getbuffer

This means as much as: define a check field, typeset this
field using the help specific setup and let \type{helpinfo}
be the on||value as well as the default. Here we use the
next setup:

\startbuffer
\setupfields
  [reset]
\setupfield
  [HelpSetup]
  [width=fit,height=fit,frame=off,option={readonly,hidden}]
\stopbuffer

\typebuffer

\getbuffer

We didn't use options before, but here we have to make sure
that users don't change the content of the field and by
default we don't want to show this field at all. The actual
text is defined as a symbol:

\startbuffer
\definesymbol [helpinfo] [\SomeHelpText]

\def\SomeHelpText%
  {\framed
     [width=\leftmarginwidth,height=fit,align=middle,style=small,
      frame=on,background=color,backgroundcolor=white,framecolor=red]
     {Click on the hide button to remove this screen}}
\stopbuffer

\typebuffer

\getbuffer

\startbuffer
\inmargin {\fitfield[Help]} Now we can put the button somewhere and
turn the help on or off by saying \goto {Hide Help} [HideField{Help}]
or \goto {Show Help} [ShowField{Help}]. Although it's better to put
these commands in a dedicated part of the screen. And try \goto
{Help} [JS(Toggle_Hide{Help})].
\stopbuffer

\getbuffer

We can place a field anywhere on the page, for instance by
using the \type {\setup...texts} commands. Here we simply
said:

\typebuffer

When one uses for instance \type {\setup...texts}, one
often wants the help text to show up on every next page.
This can be accomplished by saying:

\starttyping
\definemainfield [Help] [check] [HelpSetup] [helpinfo] [helpinfo]
\stoptyping

Every time such a field is called again, a new copy is
generated automatically. Because fields use the
objectreference mechanism and because such copies need to
be known to their parent, field inclusion is a multi||pass
typesetting job (upto 4 passes can be needed!).

When possible, appearances are shared between fields,
mainly because this saves space, but at the cost of extra
object references. This feature is not that important for
straight forward forms, but has some advantages when
composing more complicated (educational) documents.

Let us now summarize the commands we have available for
defining and typesetting fields. The main definition macro
is:

\setup{definefield}

and for radiofields we need to define the components by:

\setup{definesubfield}

Fields can be cloned and copied, where the latter can not
be set up independently.

\setup{clonefield}

\setup{copyfield}

Fields can be grouped, and such a group can have its own
settings. Apart from copied fields, we can define the
layout of a field and set options using:

\setup{setupfield}

Such a group inherits its settings from the general setup
command:

\setup{setupfields}

Fields are placed using one of:

\setup{field}

or

\setup{fitfield}

Some pages back I showed an example of:

\setup{fillinfield}

Finally there are two commands to trace fields. These
commands only make sense when one already has said: \type
{\tracefieldstrue}.

\setup{showfields}

\setup{logfields}

\section{Tooltips}

\startbuffer
Chinese people seem to have no problems in recognizing their many
different pictorial glyphs. \tooltip [left] {Western} {European
and American} people however seem to have problems in understanding
what all those \tooltip [middle] {icons} {small graphics} on their
computer screens represent. But, instead of standardizing on a set
of icons, computer programmers tend to fill the screen with so
called tooltips. Well, \tooltip {\CONTEXT} {a \TEX\ macro package}
can do tooltips too, and although a good design can do without them,
\TEX\ at least can typeset them correctly.
\stopbuffer

\getbuffer

The previous paragraph has three of such tooltips under
{\em western}, {\em icons} and {\em \CONTEXT}, each aligned
differently. We just typed:

\typebuffer

This is an official command, and thereby we can show its
definition:

\setup{tooltip}

\section{Fieldstacks}

In due time I will provide more dedicated field commands.
Currently apart from \type {\fillinfield} and \type
{\tooltip} we have \type {\fieldstack}. Let's spend a few
words on those now.

\startbuffer[somemap1]
\useexternalfigure [map -- -- --] [euro-10] [width=.3\hsize]
\useexternalfigure [map nl -- --] [euro-11] [map -- -- --]
\useexternalfigure [map nl de --] [euro-12] [map -- -- --]
\useexternalfigure [map nl de en] [euro-13] [map -- -- --]

\definesymbol [map -- -- --] [{\externalfigure[map -- -- --]}]
\definesymbol [map nl -- --] [{\externalfigure[map nl -- --]}]
\definesymbol [map nl de --] [{\externalfigure[map nl de --]}]
\definesymbol [map nl de en] [{\externalfigure[map nl de en]}]

\stopbuffer

\startbuffer[somemap2]
\definefieldstack
  [somemap]
  [map -- -- --, map nl -- --, map nl de --, map nl de en]
  [frame=on]
\stopbuffer

\startbuffer[somemap3]
\placefigure
  [left][fig:somemap]
  {Do you want to see what interfaces
   are available? Just click \goto
   {here} [JS(Walk_Field{somemap})]
   a few times!}
  {\fieldstack[somemap]}
\stopbuffer

\getbuffer[somemap1,somemap2,somemap3]

One can abuse field for educational purposes. Take for
instance \in{figure}[fig:somemap]. In this figure we can
sort of walk over different alternatives of the same
graphic. This illustration was typeset by saying:

\typebuffer[somemap3]

However, before we can ask for such a map, we need to
define a field set, which in fact is a list of symbols to
show. This list is defined using:

\typebuffer[somemap2]

which in turn is preceded by:

\typebuffer[somemap1]

\startbuffer
\placefigure
  [here][fig:anothermap]
  {Choose \goto {one} [JS(Set_Field{anothermap,2})] country,
   \goto {two} [JS(Set_Field{anothermap,3})] countries,
   \goto {three} [JS(Set_Field{anothermap,4})] countries or
   \goto {no} [JS(Set_Field{anothermap,1})] countries at all.}
  {\fieldstack
     [anothermap]
     [map -- -- --, map nl -- --, map nl de --, map nl de en]
     [frame=on]}
\stopbuffer

\getbuffer

A slightly different illustration is shown in
\in{figure}[fig:anothermap]. Here we use the same symbols
but instead say:

\typebuffer

As one can see, we can can skip the definition and pass it
directly, but I wouldn't call that beautiful.

The formal definitions are:

\setup{definefieldstack}

\setup{fieldstack}

Instead if stacking fields, you can of course also put them
alongside. This makes sense when you want to use dedicated
(visible) captions for each image.

\startbuffer
\useexternalfigure [europe]  [euro-10] [width=.3\hsize]
\useexternalfigure [holland] [euro-nl] [europe]
\useexternalfigure [germany] [euro-de] [europe]
\useexternalfigure [england] [euro-en] [europe]

\definesymbol [europe]  [{\externalfigure[europe]}]
\definesymbol [holland] [{\externalfigure[holland]}]
\definesymbol [germany] [{\externalfigure[germany]}]
\definesymbol [england] [{\externalfigure[england]}]

\definefield
  [interface] [radio] [map]
  [england,germany,holland] [holland]

\definesubfield [holland] [] [holland,europe]
\definesubfield [germany] [] [germany,europe]
\definesubfield [england] [] [england,europe]

\setupfield[map][frame=off]
\stopbuffer

\typebuffer

\getbuffer

We can for instance typeset the fields by saying:

\startbuffer
\startcombination[3]
  {\fitfield[holland]} {Dutch Interface}
  {\fitfield[germany]} {German Interface}
  {\fitfield[england]} {English Interface}
\stopcombination
\stopbuffer

\typebuffer

\startbaselinecorrection
\getbuffer
\stopbaselinecorrection



%D \starttyping
%D \defineviewerlayer[test]
%D
%D \startviewerlayer[test]Hide Me\stopviewerlayer
%D
%D \defineoverlay
%D   [WithTest]
%D   [{\overlayrollbutton[HideLayer{test}][VideLayer{test}]}]
%D
%D \framed[background=WithTest]{toggle}
%D \stoptyping



% \setupinteraction[state=start]
%
% \definepushbutton [reset]
%
% \startuniqueMPgraphic{whatever}{color}
%     fill fullcircle xysized (OverlayWidth,OverlayHeight) withcolor \MPvar{color} ;
% \stopuniqueMPgraphic
%
% \definepushsymbol [reset] [n] [\uniqueMPgraphic{whatever}{color=red}]
% \definepushsymbol [reset] [r] [\uniqueMPgraphic{whatever}{color=green}]
% \definepushsymbol [reset] [d] [\uniqueMPgraphic{whatever}{color=blue}]
%
% \starttext
%     \startTEXpage
%         \pushbutton [reset] [page(2)]
%     \stopTEXpage
%     \startTEXpage
%         \pushbutton [reset] [page(1)]
%     \stopTEXpage
% \stoptext


% \setupinteraction[state=start]
%
% \definepushbutton [reset]
%
% \startuniqueMPgraphic{whatever}{color}
%     fill fullcircle xysized (OverlayWidth,OverlayHeight) withcolor \MPvar{color} ;
% \stopuniqueMPgraphic
%
% \definepushsymbol [reset] [n] [\uniqueMPgraphic{whatever}{color=red}]
% \definepushsymbol [reset] [r] [\uniqueMPgraphic{whatever}{color=green}]
% \definepushsymbol [reset] [d] [\uniqueMPgraphic{whatever}{color=blue}]
%
% \starttext
%     \startTEXpage
%         \pushbutton [reset] [page(2)]
%     \stopTEXpage
%     \startTEXpage
%         \pushbutton [reset] [page(1)]
%     \stopTEXpage
% \stoptext

% \appendtoks
%     \let\startrob\scrn_menu_rob_start
%     \let\stoprob \relax
%     \let\rob     \scrn_menu_rob_direct
% \to \everysetmenucommands

% \protect \endinput

