Background

Set up zebra striping using extreme tables. The ConTeXt tables are generated by converting an ASCII Markdown table via pandoc.

Minimum Example

starttext

  startplacetable

  startxtable

  startxtablehead[head]

  startxrow

  startxcell Item stopxcell

  startxcell[align=left] Cost ($) stopxcell

  startxcell[align=left] Description stopxcell

  stopxrow

  stopxtablehead

  startxtablebody[body]

  dorecurse{4}{

  startxrow

  startxcell Item stopxcell

  startxcell[align=left] 100 stopxcell

  startxcell[align=left] Cow text stopxcell

  stopxrow

  }

  stopxtablebody

  startxtablefoot[foot]

  startxrow

  startxcell {bf Total} stopxcell

  startxcell[align=left] {bf 400} stopxcell

  startxcell[align=left]  stopxcell

  stopxrow

  stopxtablefoot

  stopxtable

  stopplacetable

stoptext

Problem

ConTeXt, which is rather consistent with its setup macros, does not appear to define a setupxrow or setupxcell. I had anticipated something like:

definecolor[lime][r=0.75, g=1, b=0] 

definecolor[transparentred][r=1,t=.5,a=1]

setupxrow[odd][background=lime]

setupxrow[even][background=transparentred]

This did not compile.

Question

Without using definextable to create a custom xtable definition, how would you apply zebra striping so that every other non-header row has a coloured background?

With natural tables this would have been easy because the environment let you set different values for even and odd rows.

startsetups [tablebackground]

  setupTABLE [row] [odd] [background=color,backgroundcolor=gray]

stopsetups



starttext



bTABLE[setups=tablebackground]

dorecurse{9}{bTR expanded{bTD Row recurselevel eTD} eTR}

eTABLE



stoptext

Extreme tables on the other hand don’t support this kind of setup and you have to use the overlay mechanism to create your own backgrounds for the cells.

In the overlay setting you can check the value of the currentxtablerow counter to apply a different command for odd and even rows.

startuseMPgraphic {tablebackground}

    fill OverlayBox withcolor MPcolor{gray} ;

stopuseMPgraphic



defineoverlay

  [tablebackground]

  [ifoddcurrentxtablerow

     useMPgraphic{tablebackground}%

   fi]



starttext



startxtable[background=tablebackground]

dorecurse{9}{startxrow expanded{startxcell Row recurselevel stopxcell} stopxrow}

stopxtable



stoptext

To skip the table header:

defineoverlay

  [tablebackground]

  [ifnumcurrentxtablerow>1

     ifoddcurrentxtablerowuseMPgraphic{tablebackground}fi

   fi]

To apply shading against even rows:

startuseMPgraphic {tablebackground}

  fill OverlayBox withcolor MPcolor{gray} ;

stopuseMPgraphic



defineoverlay

  [tablebackground]

  [ifnumcurrentxtablerow>1

     ifoddcurrentxtablerow else

       useMPgraphic{tablebackground}%

     fi

   fi]



setupxtable[background=tablebackground]

To apply the background against all tables in the document, use:

setupxtable[background=tablebackground]