[Tex/LaTex] Drawing boxes around words

boxes

I want to put some small boxes around certain words in a paragraph. The boxes will never contain more than one word.

The \ovalbox command described in the fancybox documentation is close to what I need. However, I found some problems:

The rounded corners do not line up with the sides perfectly.
Text to the left and right in the paragraph are pushed away.
The spacing between lines in the paragraph is increased vertically.

I would like to create boxes which:

Adjust horizontally to fit the width of the text inside.
Have rounded or beveled corners.
Can be filled with a solid color.
Will not cause any text inside or around the box to move.
Will not impact the vertical spacing of lines.

Best Answer

You can use TikZ with the overlay option and a correct anchor. That would look like this:

\documentclass{article}
\usepackage{tikz}
\newcommand\mybox[2][]{\tikz[overlay]\node[fill=blue!20,inner sep=2pt, anchor=text, rectangle, rounded corners=1mm,#1] {#2};\phantom{#2}}
\begin{document}
   \noindent
   this is some text \mybox[fill=blue!20]{box} text\\
   this is some text box text
\end{document}

You can specify extra options (like I have done here for the color). By using the overlay option and the text anchor we ensure correct placement and no influence on spacing. The phantom is added to get the normal spacing for the content of the box. This is the result of the example code:

TikZ text box

Edit: To show that the vertical spacing is not affected either, consider the following:

\documentclass{article}
\usepackage{tikz}
\newcommand\mybox[2][]{\tikz[overlay]\node[fill=blue!20,inner sep=2pt, anchor=text, rectangle, rounded corners=1mm,#1] {#2};\phantom{#2}}
\begin{document}
  \begin{minipage}{0.4\textwidth}
    \noindent
    this is some text \mybox[fill=blue!20]{box} text\\
    this is some text box text
  \end{minipage}
  \begin{minipage}{0.4\textwidth}
    \noindent
    this is some text box text\\
    this is some text box text
  \end{minipage}    
\end{document}

Which results in:

TikZ text box vertical spacing

Related Solutions

[Tex/LaTex] Non-invasive replacement for \fbox

Any box commands in math mode need to be set in all styles so TeX can pick the right one later; the \mathchoice command is what you need here. See my rant against \over on this site the other day:-) If you just use \hbox{$...$} you are starting a fresh math list at text size even in subscript position.

You can re-assert the correct spacing around your construct using \mathbin \mathop and friends, This could be done automatically by looking up the\mathcode of the character you are boxing. Inspecting bm.sty might be helpful, which does this to re-assert the correct math class after making things bold, but the issues are similar.

It's a bit late to re-create bm interrogation of \mathcode so this just looks at special cases \cdot and + but otherwise does something plausible I suspect

UPDATE At the end I place a version that does automatically pick up the math class from character tokens, things like \cdot defined by \mathchar and things like \log with explicit \mathop. I will leave the original version in place as the math class detection probably obscures the logic of the measuring which was perhaps the main part of the question.

enter image description here

\documentclass{article}

\usepackage{amsmath,color}

\makeatletter

\def\fb@cdot{\cdot}
\def\fb@p{+}
\def\@mfbox#1{%
\def\fb@{#1}%
\ifx\fb@\fb@cdot\mathbin\fi
\ifx\fb@\fb@p\mathbin\fi
{\text{\fboxsep\z@\colorbox{yellow}{$\m@th#1$}}}}
\def\@tfbox#1{{\fboxsep\z@\colorbox{yellow}{#1}}}
\def\fillbox#1{\ifmmode\expandafter\@mfbox\else\expandafter\@tfbox\fi{#1}}


\begin{document}

\vskip1em
$\fillbox{p}_{\fillbox{x}}
  \mathrel{\stackrel{\fillbox{_{~+}}}{\fillbox{\leftarrow}}}
  \fillbox{(}\fillbox{\frac{\fillbox{1}}{\fillbox{2}}}\fillbox{\cdot}
  \fillbox{a}_{\fillbox{x}}\fillbox{\cdot}%
  \fillbox{\Delta}\fillbox{t}^{\fillbox{2}}\fillbox{)} \fillbox{+}
  \fillbox{(}\fillbox{v}_{\fillbox{x}}\fillbox{\cdot}%
  \fillbox{\Delta}\fillbox{t}\fillbox{)}$\fillbox{;}\par
$\fillbox{v}_{\fillbox{x}}
  \mathrel{\stackrel{\fillbox{_{~+}}}{\fillbox{\leftarrow}}}
  \fillbox{a}_{\fillbox{x}}\fillbox{\cdot}%
  \fillbox{\Delta}\fillbox{t}$\fillbox{;}\par

\vskip1em
$p_x \mathrel{\stackrel{_{~+}}{\leftarrow}}
  (\frac{1}{2}\cdot a_x\cdot\Delta t^2) + (v_x\cdot\Delta t)$;\par
$v_x \mathrel{\stackrel{_{~+}}{\leftarrow}} a_x\cdot\Delta t$;\par

\end{document}

Version using bm-style math class detection.

\documentclass{article}

\usepackage{amsmath,color}

\makeatletter

\def\fb@eat#1#2#3#4#5{\futurelet\fb@let@token\fb@eat@}
\def\fb@eat@#1\fb@eat{%
\ifx\fb@let@token\bgroup
\else\ifx\fb@let@token\mathop
  \mathop
\else\ifx\fb@let@token\mathbin
  \mathbin
\else\ifx\fb@let@token\mathrel
  \mathrel
\else\ifx\fb@let@token\mathopen
  \mathopen
\else\ifx\fb@let@token\mathop
  \mathop
\else\ifx\fb@let@token\mathpunct
  \mathpunct
\else\ifcat.\ifcat a\noexpand\fb@let@token.\else\noexpand\fb@let@token\fi
  \afterassignment\fb@mathchar\count@\mathcode`#1\relax\fb@eat
\else\ifx\fb@let@token\mathchar
  \afterassignment\fb@mathchar\expandafter\count@\@gobble#1\relax\fb@eat
\else
    \xdef\meaning@{\meaning\fb@let@token}%
    \expandafter\fb@mchar@test\meaning@""\@nil
\fi\fi\fi\fi\fi\fi\fi\fi\fi
}


\def\@mfbox#1{%
\begingroup
\let\protect\empty
\expandafter\fb@eat\romannumeral`\Q#1\relax\fb@eat
  \ifcase\count@
    \or
    \mathop\or
    \mathbin\or
    \mathrel\or
    \mathopen\or
    \mathclose\or
    \mathpunct\or
  \fi
{\text{\fboxsep\z@\colorbox{yellow}{$\m@th#1$}}}%
\endgroup}

\edef\fb@mchar@{\meaning\mathchar}

\def\fb@mchar@test#1"#2"#3\@nil{%
  \xdef\meaning@{#1}%
  \ifx\meaning@\fb@mchar@
    \count@"#2\relax
    \fb@mathchar\fb@eat
   \fi
}

\def\fb@mathchar#1\fb@eat{%
 \divide\count@"1000 }

\def\@tfbox#1{{\fboxsep\z@\colorbox{yellow}{#1}}}
\def\fillbox#1{\ifmmode\expandafter\@mfbox\else\expandafter\@tfbox\fi{#1}}


\begin{document}


$a-b$

$a{-}b$

$a\fillbox{-}b$

$\log x + \mathrm{log}x$


$\fillbox{\log} \fillbox{x} \fillbox{+} \fillbox{\mathrm{log}}\fillbox{x}$


$\fillbox{0}$

$ a \cdot b {\cdot} c$

$ a \fillbox{\cdot} b \fillbox{{\cdot}}c $


$a \fillbox{\mathchar"2201} b  \fillbox{{\mathchar"2201}} c $


$ a - b < \alpha $

$\fillbox{a} \fillbox{-} \fillbox{b} \fillbox{<} \fillbox{\alpha}$

$\fillbox{a+b}$

$a = \sqrt{h}$

$a = \fillbox{\sqrt{h}}$


\vskip1em
$\fillbox{p}_{\fillbox{x}}
  \mathrel{\stackrel{\fillbox{_{~+}}}{\fillbox{\leftarrow}}}
  \fillbox{(}\fillbox{\frac{\fillbox{1}}{\fillbox{2}}}\fillbox{\cdot}
  \fillbox{a}_{\fillbox{x}}\fillbox{\cdot}%
  \fillbox{\Delta}\fillbox{t}^{\fillbox{2}}\fillbox{)} \fillbox{+}
  \fillbox{(}\fillbox{v}_{\fillbox{x}}\fillbox{\cdot}%
  \fillbox{\Delta}\fillbox{t}\fillbox{)}$\fillbox{;}\par
$\fillbox{v}_{\fillbox{x}}
  \mathrel{\stackrel{\fillbox{_{~+}}}{\fillbox{\leftarrow}}}
  \fillbox{a}_{\fillbox{x}}\fillbox{\cdot}%
  \fillbox{\Delta}\fillbox{t}$\fillbox{;}\par

\vskip1em
$p_x \mathrel{\stackrel{_{~+}}{\leftarrow}}
  (\frac{1}{2}\cdot a_x\cdot\Delta t^2) + (v_x\cdot\Delta t)$;\par
$v_x \mathrel{\stackrel{_{~+}}{\leftarrow}} a_x\cdot\Delta t$;\par

\end{document}

Producing

enter image description here

[Tex/LaTex] Color box with rounded corners around a fragment of a formula

A solution with hf-tikz (requires two compilation runs):

\documentclass[dvipsnames]{article}
\usepackage{amsmath}
\usepackage[customcolors]{hf-tikz}
\definecolor{My}{RGB}{0,31,63}
\definecolor{MyConst}{RGB}{128,128,128}
\definecolor{MyFunc}{RGB}{0,75,107}
\definecolor{MyIndep}{RGB}{127,55,0}
\definecolor{MySubst}{RGB}{250,230,230}
\newcommand{\const}[1]{{\color{MyConst}\mathrm{#1}}}     % normal constant
\newcommand{\uconst}[1]{\mathrm{#1}}                     % universal mathematical constant
\newcommand{\var}[1]{{\color{MyIndep}#1}}                % independent variable
\newcommand{\subst}[1]{{\colorbox{MySubst}#1}}           % substitution

\hfsetfillcolor{Lavender!50}
\hfsetbordercolor{white}

\begin{document}
\[
\color{My}
{\color{MyFunc}\Psi} =
\const{\Psi_{_0}}\;
\uconst{e}^{\uconst{i} \left(   
    \tikzmarkin{a}(0.01,-0.175)(-0.015,0.3)\frac{p}{\const{\hbar}}\tikzmarkend{a}
    \var{x} - \tikzmarkin{b}(0.01,-0.175)(-0.015,0.3)\frac{E}{\const{\hbar}}\tikzmarkend{b}\var{t} \right) }
\]
\end{document}

The result:

enter image description here

Remarks:

it is better to use \[ \] rather than $$ $$;
the package allows you to not set in math mode the text inside a \colorbox: one just have to declare where the delimiters of the box should be positioned.

From version 0.3 of the package, things are a bit more user-friendly as shown in hf-tikz doesn't box around equation. The above code can be written thanks to styles as:

\documentclass[dvipsnames]{article}
\usepackage{amsmath}
\usepackage[customcolors]{hf-tikz}
\definecolor{My}{RGB}{0,31,63}
\definecolor{MyConst}{RGB}{128,128,128}
\definecolor{MyFunc}{RGB}{0,75,107}
\definecolor{MyIndep}{RGB}{127,55,0}
\definecolor{MySubst}{RGB}{250,230,230}
\newcommand{\const}[1]{{\color{MyConst}\mathrm{#1}}}     % normal constant
\newcommand{\uconst}[1]{\mathrm{#1}}                     % universal mathematical constant
\newcommand{\var}[1]{{\color{MyIndep}#1}}                % independent variable
\newcommand{\subst}[1]{{\colorbox{MySubst}#1}}           % substitution

% available from version 0.3
\tikzset{offset def/.style={
    above left offset={-0.015,0.3},
    below right offset={0.01,-0.175},
  },
  hl/.style={
    offset def,
    set fill color=Lavender!50,
    set border color=white,
  }
}

\begin{document}
\[
\color{My}
{\color{MyFunc}\Psi} =
\const{\Psi_{_0}}\;
\uconst{e}^{\uconst{i} \left(   
    \tikzmarkin[hl]{a}\frac{p}{\const{\hbar}}\tikzmarkend{a}
    \var{x} - \tikzmarkin[hl]{b}\frac{E}{\const{\hbar}}\tikzmarkend{b}\var{t} \right) }
\]
\end{document}

Procedure to get .png output

After reading the comments below, here is a way to get a .png. The standalone class here really helps since it has a png class option.

Save as test.tex:

\documentclass[dvipsnames,png, border=2pt]{standalone}
\usepackage{amsmath}
\usepackage[customcolors]{hf-tikz}
\definecolor{My}{RGB}{0,31,63}
\definecolor{MyConst}{RGB}{128,128,128}
\definecolor{MyFunc}{RGB}{0,75,107}
\definecolor{MyIndep}{RGB}{127,55,0}
\definecolor{MySubst}{RGB}{250,230,230}
\newcommand{\const}[1]{{\color{MyConst}\mathrm{#1}}}     % normal constant
\newcommand{\uconst}[1]{\mathrm{#1}}                     % universal mathematical constant
\newcommand{\var}[1]{{\color{MyIndep}#1}}                % independent variable
\newcommand{\subst}[1]{{\colorbox{MySubst}#1}}           % substitution

\hfsetfillcolor{Lavender!50}
\hfsetbordercolor{white}

\begin{document}
$
\color{My}
{\color{MyFunc}\Psi} =
\const{\Psi_{_0}}\;
\uconst{e}^{\uconst{i} \left(   
    \tikzmarkin{a}(0.01,-0.175)(-0.015,0.3)\frac{p}{\const{\hbar}}\tikzmarkend{a}
    \var{x} - \tikzmarkin{b}(0.01,-0.175)(-0.015,0.3)\frac{E}{\const{\hbar}}\tikzmarkend{b}\var{t} \right) }
$
\end{document}

and compile with:

pdflatex -shell-escape test.tex

This will create

test.pdf
test.png

perfectly cropped.

Best Answer

Related Solutions

[Tex/LaTex] Non-invasive replacement for \fbox

[Tex/LaTex] Color box with rounded corners around a fragment of a formula

Related Question