Fine-tuning placement of arrows inside TikZ nodes

Question

I would like to have a TikZ node with a few lines of text inside. The node should be a rectangle, wider than the text, and the text should be aligned to the left. After each line of text I'd like to put arrows going out to other nodes. This is what I got so far:

\documentclass{standalone}

\usepackage{tikz}
\usetikzlibrary{matrix,positioning,calc}

\makeatletter
\newcommand{\gettikzxy}[3]{%
  \tikz@scan@one@point\pgfutil@firstofone#1\relax
  \edef#2{\the\pgf@x}%
  \edef#3{\the\pgf@y}%
}
\makeatother



\begin{document}

\begin{tikzpicture}[innode/.style={inner sep=0pt, minimum width=1pt},
                    env/.style={draw,rectangle,align=left,inner sep=0.3cm}]
  \node[env,text width=4cm,matrix](q1){\node[innode](sp){first item};\\
                                       \node[innode](at){and the second item};\\};
  %
  \node(c1)[below=of q1.south west,anchor=north]{\ttfamily code for 2};
  \node(c2)[below=of c1.south east,anchor=east]{\ttfamily code for 1 goes here};
  %
  \gettikzxy{(c1)}{\xcu}{\ycu}
  \gettikzxy{(c2)}{\xcd}{\ycd}
  \gettikzxy{(at.east)}{\xate}{\yate}
  \gettikzxy{(sp.east)}{\xspe}{\yspe}
  %
  \draw[->] (sp.east) -- ++(3,0)
                      -- ($ (\xspe,\ycd) + (3,0) $)
                      -- (c2.east);
  \draw[->] (at.east) -- ++(2,0)
                      -- ($ (\xate,\ycu) + (2,0) $)
                      -- (c1.east);
\end{tikzpicture}

\end{document}

However, the arrows start a bit too far from the end of the lines. Is there a better way to do what I'm trying to do, and how do I keep the arrows starting closer to the text?

Answer 1

If you set nodes={anchor=west} in the matrix options, the cells in the matrix will be left-aligned without setting the text width explicitly. That way, the line will start close to the text even if the texts have different lengths.

Note that for the connecting lines, you can simply use the |- syntax to get an orthogonal connection, instead of using the calc syntax.

\documentclass[border=5mm]{standalone}

\usepackage{tikz}
\usetikzlibrary{matrix,positioning}

\makeatletter
\newcommand{\gettikzxy}[3]{%
  \tikz@scan@one@point\pgfutil@firstofone#1\relax
  \edef#2{\the\pgf@x}%
  \edef#3{\the\pgf@y}%
}
\makeatother



\begin{document}

\begin{tikzpicture}[innode/.style={inner sep=0pt, minimum width=1pt},
                    env/.style={draw,rectangle,align=left,inner sep=0.3cm}]
  \node[env,matrix, nodes={anchor=west}](q1){\node[innode](sp){first item};\\
                                       \node[innode](at){and the second item};\\};
  %
  \node(c1)[below=of q1.south west,anchor=north]{\ttfamily code for 2};
  \node(c2)[below=of c1.south east,anchor=east]{\ttfamily code for 1 goes here};
  %
  \gettikzxy{(c1)}{\xcu}{\ycu}
  \gettikzxy{(c2)}{\xcd}{\ycd}
  \gettikzxy{(at.east)}{\xate}{\yate}
  \gettikzxy{(sp.east)}{\xspe}{\yspe}
  %
  \draw[->] (sp.east) -- ++(3,0) |- (c2.east);
  \draw[->] (at.east) -- ++(1,0) |- (c1.east);
\end{tikzpicture}

\end{document}

Answer 2

It's possible to use here tkz-linknodes

\documentclass{scrartcl}
\usepackage{tkz-linknodes}
\usetikzlibrary{matrix,positioning}


\begin{document}
\hspace*{3cm}
\begin{NodesList}
\begin{tikzpicture}[innode/.style={inner sep=0pt, minimum width=1pt},
                    env/.style={draw,rectangle,align=left,inner sep=0.3cm}]
  \node[env,matrix, nodes={anchor=west}](q1){%
                                \node[innode](sp){first item\AddNode};  \\
                                \node[innode](at){and the second item\AddNode[2]};\\};

  \node(c1)[below=of q1.south west,anchor=north]{\ttfamily code for 2\AddNode };
  \node(c2)[below=of c1.south east,anchor=east]{\ttfamily code for 1 goes here\AddNode[2]};
\LinkNodes[margin=9cm]{}
\LinkNodes[margin=10cm]{}   

\end{tikzpicture}
\end{NodesList}

\end{document}