4

In my answer to question How do I repeat the first table row on every page using longtable inside of tcolorbox?

I suggest to (between others) to use makecell package to define head of table and later I sow that the firs row is not colored as expected. It doesn't cover all row. Than I try to correct this with use of cellcolor construct as should be correctly done, when you use multicolumn (simplified MWE from mentioned question):

\documentclass[12pt]{article}
    \usepackage[utf8]{inputenc}

    \usepackage[table]{xcolor}
    \usepackage{longtable}
    \usepackage{makecell}
\renewcommand\theadfont{\bfseries}

\usepackage[active,tightpage]{preview}
\PreviewEnvironment{longtable}%
    \setlength\PreviewBorder{1em}

    \begin{document}
\begin{longtable}{|*{9}{b{\dimexpr 0.11\linewidth-2\tabcolsep}|}}
    \hline
    \multicolumn{8}{|c|}{\cellcolor{gray!30}{\thead{head\\ 1}}}
    & \cellcolor{gray!30}{\thead{head\\ 2}}   \\    \hline
1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
    \hline\hline
\endfirsthead
    \hline
1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
    \hline\hline
\endhead
A & B & C & D & E & F & G & H & I  \\
J & K & L & M & N & O & P & Q & R  \\
S & T & U & V & W & X & Y & Z &    \\
    \hline\hline
\end{longtable}
    \end{document}

and discover that that head inmulticolumn doesn't has width of it and consequently head background color doesn't fill complete cell.

enter image description here

I Check makecell documentation, but doesn't find valuable information how to stretch actual head to cover entire cell. How to achieve that entire multicolum cell background will be colored?

addendum: for this particular case the stretch \thead over whole \multicolumn can be done on the following way: instead of

\multicolumn{8}{|c|}{\thead{\hfill head\hfill\\ 1}}

the multi column cell should be defined as

\multicolumn{8}{|p{\dimexpr 0.88\linewidth-\tabcolsep}|}{\thead{\hfill head\hfill\\ 1}}

where \dimexpr 0.88\linewidth-\tabcolsep is the width of multi col cell. then the result is:

enter image description here

however, general solutions are given in answers below.

Zarko
  • 296,517

2 Answers2

4

If you put the \thead in the \multicolumn{|c|} in a \colorbox, it works (somewhat redundantly…):

\documentclass[12pt]{article}
\usepackage[utf8]{inputenc}

\usepackage{xcolor}%[table]
\usepackage{array, colortbl}
\usepackage{longtable, ltablex}
\usepackage{makecell}
\renewcommand\theadfont{\bfseries}

\usepackage[active,tightpage]{preview}
\PreviewEnvironment{longtable}%
\setlength\PreviewBorder{1em}

\begin{document}

\begin{longtable}{|*{9}{b{\dimexpr 0.11\linewidth-2\tabcolsep}|}}%
  \hline
  \rowcolor{gray!30}\multicolumn{8}{|c|}{{\colorbox{gray!30}{\thead{head\\ 1}}}}
  & \thead{head\\ 2} \\ \hline
  1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
  \hline\hline
  \endfirsthead
  \hline
  1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
  \hline\hline
  \endhead
  A & B & C & D & E & F & G & H & I \\
  J & K & L & M & N & O & P & Q & R \\
  S & T & U & V & W & X & Y & Z & \\
  \hline\hline
\end{longtable}

\end{document}

enter image description here

Bernard
  • 271,350
  • Indeed. But now I need to manually calculate width of columns which are spanned by multicolumn. This can become annoying/problematic when the widths of column are not equal and/or determined with specifier with not a priory given width. – Zarko May 26 '15 at 06:46
  • 1
    @Zarko: I changed the code to avoid those calculations: it's enough to put to add a \colorbox. See my updated answer. – Bernard May 26 '15 at 07:59
  • now I'm total confused. Why now this work and didn't in my first tray? I need detail examination of all my "experiments", to see where are differences. One another observation: you put array package twice in preamble, probably by mistake. I try to compile without it and also without ltablex package and obtain the same results as you show in your answer. – Zarko May 26 '15 at 08:45
  • Now I observe differences: you add colortab in preamble and use colorbox instead cellcolor ... Good to know, thank you! I will change now my acceptances of answer. – Zarko May 26 '15 at 08:51
  • Yes, array was loaded twice by mistake, I've corrected. I tested, and it doesn't seem to be required. I generally add it because it extends the syntax of the original array environment. As to ltablex it is there because I tested with a tabularx environment (it allows the latter to break across pages), but I get an error which I don't understand, about a spurious }. You can remove it. – Bernard May 26 '15 at 09:07
2

I don't think that makecell is fully compatible with colortbl. However, you can easily emulate \thead:

\documentclass[12pt]{article}
\usepackage[utf8]{inputenc}

\usepackage[table]{xcolor}
\usepackage{longtable}
\newcommand{\thead}[1]{%
  \bfseries
  \begin{tabular}{@{}c@{}}
  \vrule height 1.2\ht\strutbox width 0pt\ignorespaces
  #1
  \unskip\vrule depth 1.2\dp\strutbox width 0pt
  \end{tabular}%
}

\begin{document}

\begin{longtable}{|*{9}{b{\dimexpr 0.11\linewidth-2\tabcolsep-\arrayrulewidth}|}}
\hline
\multicolumn{8}{|c|}{\cellcolor{gray!30}{\thead{head\\ 1}}}
    & \cellcolor{gray!30}{\thead{head\\ 2}}   \\
\hline
1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
\hline
\endfirsthead
\hline
1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
\hline
\endhead
A & B & C & D & E & F & G & H & I  \\
J & K & L & M & N & O & P & Q & R  \\
S & T & U & V & W & X & Y & Z &    \\
\hline
\end{longtable}

\end{document}

enter image description here

Here's a minimal example:

\documentclass[12pt]{article}

\usepackage[table]{xcolor}
\usepackage{makecell}
\renewcommand{\theadfont}{\bfseries}

\begin{document}

\begin{tabular}{|c|c|c|}
\hline
\multicolumn{2}{|c|}{\cellcolor{gray!30}\thead{head\\1}} & \thead{head\\2} \\
\hline
111 & 222 & 333 \\
\hline
\end{tabular}

\end{document}

enter image description here

Using \rowcolor doesn't solve the problem.

egreg
  • 1,121,712
  • thank you for editing my question and for answer. You confirm my suspect that makecell and colortab are not full compatible. As I see, thead doesn't use complete width of "multi-column" cell.That means, that there is a chance that one day this will be fixed :-). For particular case, mentioned in my question, where the first row is not multi-lined, is then better solution not use makecell and thead at all. Other wise, your solution is what I will use in future in similar cases. – Zarko May 25 '15 at 22:53