Angled cells and background colors in tabular environment

Question

I'm trying to make a table where the top row is angled at 45 degrees and has a background fill; there's a few different ways I've found of making angled text in cells, but one thing I can't figure out is how to make background color follow the angle along with the text. I've got code from here: Rotated column titles in tabular which creates the angles I want, but it overrides column color. I can use the rotating package to keep the color, but that doesn't angle the cell itself, only the text in it.

\documentclass{article}
\usepackage{adjustbox}
\usepackage{array}
\usepackage{xcolor,colortbl}
\usepackage{multirow}
\newcolumntype{R}[2]{%
    >{\adjustbox{angle=#1, lap=\width-(#2)}\bgroup}%
    l%
    <{\egroup}%
}
\newcommand*\rot{\multicolumn{1}{R{45}{1em}}}
\newcolumntype{a}{>{\columncolor{blue!15}}l}
\begin{document}
\begin{tabular}{lla}
    & \rot{Column 1}    & \rot{Column 2} \
\hline
Information & X         & \
More information    &           & X \
\end{tabular}
\end{document}

I'm assuming I need to insert a column color into the \newcolumntype but I'm not sure where it goes with the other code.

Answer 1

I'm not sure to understand exactly what you want, but here is a suggestion with the environment {NiceTabular} of nicematrix.

\documentclass{article}
\usepackage{xcolor}
\usepackage{nicematrix}
\usepackage{tikz}
\usetikzlibrary{calc}
\begin{document}
\NewDocumentCommand{\rot}{m}{\rlap{\hspace*{2mm}\rotatebox{45}{#1}}}
\NewDocumentCommand{\ColumnColor}{mm} % #1 : number of column ; #2 ; color
  {
    \begin{tikzpicture} [fill = #2]
    \fill let \p1 = (1) , \p2 = (2) , \n1 = { \y1 - \y2 }
          in (2-|#1) -- ($(2-|#1)+(\n1,\n1)$) 
                     -- ($(2-|\inteval{#1+1})+(\n1,\n1)$) 
                     -- (2-|\inteval{#1+1}) 
                     -- cycle ;
    \fill (2-|#1) rectangle (last-|\inteval{#1+1}) ; 
    \end{tikzpicture}
  }
\begin{NiceTabular}{lll}
\CodeBefore
  \ColumnColor{2}{red!15}
  \ColumnColor{3}{blue!15}
\Body
                    & \rot{Column 1} & \rot{Column 2} \
  \Hline
  Information      & X              &                \
  More information &                & X              \
\end{NiceTabular}
\end{document}

You need several compilations (because of the PGF/Tikz nodes used by nicematrix).

---

If you want to add a color to the first row (excepted for the ``angled cells''), you can't use \rowcolor in the \CodeBefore for a technical reason: the commands \rowcolor, \cellcolor, \columncolor, etc. don't act in the order of their occurrence in the \CodeBefore because they are grouped by color (in order to avoid thin white lines between panels of the same color in some PDF viewers).

Maybe I should add to key to the package nicematrix in order to disable that feature for the situations like this one.

With the current version of nicematrix, you have to define your own command \RowColor which will do the job by using Tikz to fill a rectangle delimited by the PGF/Tikz provided by nicematrix.

\documentclass{article}
\usepackage{xcolor}
\usepackage{nicematrix}
\usepackage{tikz}
\usetikzlibrary{calc}
\begin{document}
\NewDocumentCommand{\rot}{m}{\rlap{\hspace*{2mm}\rotatebox{45}{#1}}}
\NewDocumentCommand{\ColumnColor}{mm} % #1 : number of column ; #2 : color
  {
    \begin{tikzpicture} [fill = #2]
    \fill let \p1 = (1) , \p2 = (2) , \n1 = { \y1 - \y2 }
          in (2-|#1) -- ($(2-|#1)+(\n1,\n1)$) 
                     -- ($(2-|\inteval{#1+1})+(\n1,\n1)$) 
                     -- (2-|\inteval{#1+1}) 
                     -- cycle ;
    \fill (2-|#1) rectangle (last-|\inteval{#1+1}) ; 
    \end{tikzpicture}
  }
\NewDocumentCommand{\RowColor}{mm} % #1 number of row ; #2 : color
  {
    \begin{tikzpicture} [fill = #2]
    \fill (#1-|1) rectangle (\inteval{#1+1}-|last) ;
    \end{tikzpicture}
  }
\begin{NiceTabular}{lll}
\CodeBefore
  \RowColor{1}{gray!10}
  \ColumnColor{2}{red!15}
  \ColumnColor{3}{blue!15}
\Body
                    & \rot{Column 1} & \rot{Column 2} \
  \Hline
  Information      & X              &                \
  More information &                & X              \
\end{NiceTabular}
\end{document}