How to make a tikz node, top-aligned with the rest of the text?

Question

If I write

before-text \begin{minipage}[t]{5cm} line1\\line2\\line3\\ \end{minipage} after-text

I get a box, whose top is aligned to the top of "before text". I would like to have the same, when using a tikz node (with line1\\line2\\line3\\) instead of minipage. But the default behaviour is to align the bottom of the node with the bottom of the "before text". How can I do this?

Answer 1

To align the contents of the tikzpicture you have some possibilities.

TikZ calculate the bounding box of every picture. If you don't set the bounding box manual the whole picture will be used. TikZ define a node which can be use to reference the calculated bounding box. The node name is current bounding box. However important is the key baseline which is the reference for the vertical alignment of the tikzpicture. This key can be set at the beginning of the environment.

An example with current boundingbox:

\documentclass[a4paper, 11pt]{standalone}
\usepackage{tikz}

\begin{document}
Text before
\begin{tikzpicture}[baseline={([yshift={-\ht\strutbox}]current bounding box.north)},outer sep=0pt,inner sep=0pt]
\draw (0,0)--(1,0);
\draw (2,0)--(3,0);
\node[align=left,] at(1.5,0) {\strut line1\\line2\\line3\\line4};
\end{tikzpicture}
Text between
\begin{tikzpicture}[baseline=(current bounding box.south),outer sep=0pt,inner sep=0pt]
\draw (0,0)--(1,0);
\draw (2,0)--(3,0);
\node[align=left] at (1.5,0) {\strut line1\\line2\\line3\\line4};
\end{tikzpicture}
Text after
\end{document}

An example where the node was named and the node can be used for the vertical alignment. The example was provided by percusse

\documentclass[a4paper, 11pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{calc}

\begin{document}

before text 
\tikz[baseline={([yshift={-\ht\strutbox}]a.north)},outer sep=0pt,inner sep=0pt] \node[align=center] (a) {\strut line1\\line2\\line3\\line4};
text between
\tikz[baseline=(a.south),outer sep=0pt,inner sep=0pt] \node[align=center] (a) {\strut line1\\line2\\line3\\line4};
text after
\end{document}

Every node / tikzpicture have a space around. The spaces are inner sep and outer sep. To align the text you have to set this seps to 0pt. (or calculate the new resulting height). The command \strut for the alignment of the north is required to set a fix height at the first line of the node. In this way you can shift the baseline by a fix height.

Answer 2

If you add text width=<width> to the node option the content is wrapped in a top align minipage internally. Together with the baseline option you can achieve the requested alignment. The drawback is that you need to set the width of the node. I tried replacing the internal minipage with a varwidth environment, but without success.

\documentclass{article}

\usepackage{tikz}

\begin{document}

before
\begin{tikzpicture}[baseline={(A.base)}]
    \node [text width=2cm] (A) at (0,0) {first\\second\\third};
\end{tikzpicture}
after

\end{document}

Answer 3

\documentclass[a4paper, 11pt]{standalone}
\usepackage{tikz}    
\begin{document}

before text 
\raisebox{\dimexpr -\height+\baselineskip-1pt}{% 1pt is \interlineskip
  \tikz \node (a) {\tabular{c} line1\\line2\\line3\\line4\endtabular};}
text between
\raisebox{\dimexpr-0.5\baselineskip-1pt}{%
  \tikz \node (b) {\tabular{c} line1\\line2\\line3\\line4\endtabular};}
text after

\end{document}

Answer 4

I'm taking another bite at the same question. With a vastly improved solution, I think --- thus the new answer.

I looked at tikz code: the vertical alignments are hard wired to the bottom line, except the fixed width environment in LaTeX (and only LaTeX). I'm going to prepare a patch for this, soon, until then, an easy hack.

\documentclass{minimal}
\usepackage{tikz}

\makeatletter
\tikzset{
  base/.is choice,
  base/top/.code={\let\vbox\vtop},
  base/bottom/.code={\def\pgfutil@minipage[t]{\minipage[b]}},
  % base/bottom/.code={}, % for plain TeX
}
\makeatother

\begin{document}
text before \rule{1cm}{0.4pt}
\begin{tikzpicture}
  [every node/.style={align=center,anchor=base},baseline=0pt]
  \node at (0,0)[text width=2cm,base=bottom]
        {automatic line breaks with base at the bottom};
  \node at (2,0)[text width=2cm,base=top]
        {automatic line breaks with base at the top};
  \node at (4,0)[text width=2cm,base=bottom]
        {manual\\line breaks\\with\\base at the\\bottom};
  \node at (6,0)[text width=2cm,base=top]
        {manual\\line breaks\\with\\base at the\\top};
\end{tikzpicture}
\rule{1cm}{0.4pt} text after
\end{document}

Extremely simple to use: say base=top or base=bottom. If you don't specify anything, you get the (crazy) default behaviour.

As far as I can see, redefining \vbox (uuuu, scary!:) and \minipage has no ill effects. Looking at the code, all the redefinitions stay in a very local group. ---Ahh well, as you can see from the updated image, there is a side effect... But the alignment works ;-)

Answer 5

I was bugged by the same problem for quite a while... and I think I have finally found a solution that's usable in everyday life ;-)

I defined a new (generic) anchor top base, which does the job in non-complicated cases.

\documentclass{article}
\usepackage{tikz}

\makeatletter
\pgfdeclaregenericanchor{top base}{%
  \csname pgf@anchor@#1@north\endcsname
  \pgf@anchor@generic@top@base@main
}
\pgfdeclaregenericanchor{top base west}{%
  \csname pgf@anchor@#1@north west\endcsname
  \pgf@anchor@generic@top@base@main
}
\pgfdeclaregenericanchor{top base east}{%
  \csname pgf@anchor@#1@north east\endcsname
  \pgf@anchor@generic@top@base@main
}
\def\pgf@anchor@generic@top@base@main{%
  {%
    \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/pgf/outer ysep}}%
    \advance\pgf@y-\pgf@ya
    \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/pgf/inner ysep}}%
    \advance\pgf@y-\pgf@ya
    \pgf@ya=0pt
    \pgfutil@loop
    \ifdim\pgf@y>\baselineskip
      \advance\pgf@y-\baselineskip
      \advance\pgf@ya\baselineskip
    \pgfutil@repeat
    \global\pgf@y=\pgf@ya
  }%
}
\makeatother


\begin{document}

The following node
\begin{tikzpicture}
  [align=center,baseline=(a.base)]
  \node(a){sticks\\up};
\end{tikzpicture}
while the next one
\begin{tikzpicture}
  [align=center,baseline=(a.top base)]
  \node(a){sticks\\down};
\end{tikzpicture}

\end{document}

The anchor (actually, the three anchors, because I also defined the east and the west version) is then of course usable also in within a tikzpicture. An example follows.

\begin{tikzpicture}[align=center,every node/.style={draw,outer sep=2pt}]
  \node(a){first node\\with\\some text};
  \node[anchor=top base west,at=(a.top base east)] (b)
       {this node\\is anchored\\at top base\\and positioned\\at top
         base\\of the node\\on its left};
  \node[anchor=base west,at=(b.top base east)](c)
        {this node\\is anchored\\at base\\and positioned\\at top
         base\\of the node\\on the left};
  \node[anchor=top base west,at=(c.base east)](d)
        {anchored\\at base\\positioned\\at top
         base\\of the left node};
\end{tikzpicture}

How does it work? It first deduces the height (without depth) of the original box where the node text was typeset. Then it estimates the number of newlines by counting how many \baselineskips fit in the height, and sets the top base anchor that much to the north.

The problems: two. First, the procedure fails if a font larger than \baselineskip was used in the box --- ok, I can live with that. Second, much more problematically, it only works for some shapes (rectangle, ellipse, and some others). For other shapes it is impossible to deduce the height of the original box; the information is of course there when saved anchors are computed, but then it gets lost... more precisely, it cannot be recovered from saved anchors and dimensions. I'm thinking the only way to hack this is to define a new shape (say circle'), inheriting everything from circle and adding additional saved dimensions/anchors.

I hope this helps, although it is not as generic as the name suggests :-)