Automatic connection of text points in tikz-qtree

Question

I have to draw pictures like the following a lot:

I want to use tikz-qtree, since I have a lot of trees and this package simplifies things considerably. Right now I use the following code, since it is not possible to have nodes in nodes and tikz-qtree makes the tree elements nodes. So I use the grid code from How can I show coordinates by grid in TikZ automatically? and draw lines from absolute positions to other absolute positions. This is time consuming, it never looks right, and I have to redo it when the font size changes. Is there a better way to do this?

\documentclass{minimal}

\usepackage{tikz-qtree}
\tikzset{every roof node/.append style={inner sep=0.1pt,text height=2ex,text depth=0.3ex}}

\newcommand{\sliste}[1]{%
\mbox{%
$\left\langle\mbox{\scshape #1}\right\rangle$}%
}


\begin{document}

\begin{tikzpicture}
\tikzset{level 1+/.style={level distance=3\baselineskip}}
\tikzset{frontier/.style={distance from root=12\baselineskip}}
%\draw (-3,-5) to[grid with coordinates] (4,0);
\Tree[.S
        [.{V \sliste{ S$\!/\!/$V }} 
          [.V liest$_k$ ] ]
        [.{S$\!/\!/$V}
           [.NP Jens ]
           [.{V$'$$\!/\!/$V}
             [.NP \edge[roof]; {das Buch} ]
             [.{V$\!/\!/$V} \_$_k$ ] ] ] ]
\draw[semithick,<->,color=green] (3.1,-3.9) ..controls +(south east:.5) and +(south west:.5)..(2.7,-3.9);
\draw[semithick,<->,color=green] (3.5,-3.7) ..controls +(east:.5) and +(east:.5)..(2.8,-2.5);
\draw[semithick,<->,color=green] (2.8,-2.3) ..controls +(east:.5) and +(east:.5)..(1.7,-1.1);
\draw[semithick,<->,color=green] (1.5,-0.9) ..controls +(north:.5) and +(north:.5)..(-0.8,-0.9);
\draw[semithick,<->,color=green] (-0.7,-1.1) ..controls +(south east:.2) and +(north east:.5)..(-1.0,-2.4);
\end{tikzpicture}



\end{document}

Edit:

I followed the suggestion and used tikzmark and \subnode:

\documentclass{minimal}


\usepackage{tikz-grid}


\usepackage{tikz-qtree}
\tikzset{every roof node/.append style={inner sep=0.1pt,text height=2ex,text depth=0.3ex}}

\usetikzlibrary{tikzmark}

\newcommand{\sliste}[1]{%
\mbox{%
$\left\langle\mbox{\scshape #1}\right\rangle$}%
}


\begin{document}

\begin{tikzpicture}
\tikzset{level 1+/.style={level distance=3\baselineskip}}
\tikzset{frontier/.style={distance from root=12\baselineskip}}
\Tree[.S
        [.{V \sliste{ S$/\!/$\subnode{vcomp}{V} }} 
          [.{\subnode{vliest}{V}} liest$_k$ ] ]
        [.{S$/\!/$\subnode{vs}{V}}
           [.NP Jens ]
           [.{V$'$$\!/\!/$\subnode{vbar}{V}}
             [.NP \edge[roof]; {das Buch} ]
             [.{\subnode{vzero}{V}$\!/\!/$\subnode{vdsl}{V}} \_$_k$ ] ] ] ]
\draw[semithick,<->,color=green] (vcomp.east) ..controls +(south east:.2) and +(north east:.5)..(vliest.east);
\end{tikzpicture}



\end{document}

The result is funny: It works if I use pdflatex and have no AUX file. As soon as there is an AUX file, the code produces two pages or the arrows are distributed over the page. Hm.

Edit 2:

I followed Allen Mun's suggestion and worked further on similar examples:

\documentclass{minimal}


\usepackage{tikz-grid}


\usepackage{tikz-qtree}
\tikzset{every roof node/.append style={inner sep=0.1pt,text height=2ex,text depth=0.3ex}}

\usetikzlibrary{tikzmark}

\newcommand{\sliste}[1]{%
\mbox{%
$\left\langle\mbox{\scshape #1}\right\rangle$}%
}

\newcommand{\trace}{\raisebox{0.2ex}{\_}\rule{0cm}{0.7em}}

\begin{document}

\begin{tikzpicture}[
level 1+/.style={level distance=3\baselineskip},
frontier/.style={distance from root=15\baselineskip},
connect/.style={semithick,<->,color=green}]
\Tree[.S
        [.\node (NP) {NP}; \edge[roof]; {das Buch} ]
        [.\node (S/NP) {S/NP};
          [.{V \sliste{ S/$\!$/V }} 
            [.V liest$_k$ ] ]
           [.\node (S//V/NP) {S$/\!/$V/NP};
             [.\node (NP/NP) {NP/NP}; \trace{} ]
             [.{V$'$$\!/\!/$V}
               [.NP Jens ]
               [.{V$\!/\!/$V} \_$_k$ ] ] ] ] ] ]
\draw[connect] (NP/NP) [bend right] to (S//V/NP.south east);
\draw[connect] (S//V/NP.north east) [bend right] to (S/NP.east);
\draw[connect] (S/NP.north east) [bend right] to (NP);
\end{tikzpicture}


\end{document}

The intention of this figure is to show that the NP information is shared. So here it would be great to be able to connect to the NP nodes directly.

Answer 1

There's no need to be so complicated. Any tikz-qtree node label can be an explicit TikZ \node command, so you can name your nodes without too much extra work. I've also used a simpler syntax for the arrows, so that you don't need to specify controls (and which I think makes the arrows a little nicer too.) There's no need for subnodes even for the smaller arrows, since they can be shortened with the shorten key (as in the V//V arrow in the example.)

As Qrrbrbirlbel notes, using the forest package makes this slightly easier, since it allows you to simply specify a label for any node without using an explicit \node command, but otherwise the basic procedure is the same.

\documentclass{article}

\usepackage{tikz-qtree}
\tikzset{every roof node/.append style={inner sep=0.1pt,text height=2ex,text depth=0.3ex}}

\newcommand{\sliste}[1]{%
\mbox{%
$\left\langle\mbox{\scshape #1}\right\rangle$}%
}


\begin{document}


\begin{tikzpicture}[
level 1+/.style={level distance=3\baselineskip},
frontier/.style={distance from root=12\baselineskip},
connect/.style={semithick,<->,color=green}]
\Tree[.S
        [.\node (V1) {V \sliste{ S$\!/\!/$V }}; 
          [.\node(V){V}; liest$_k$ ] ]
        [.\node (S/V) {S$\!/\!/$V};
           [.NP Jens ]
           [.\node(V'V) {V$'$$\!/\!/$V};
             [.NP \edge[roof]; {das Buch} ]
             [.\node(V/V) {V$\!/\!/$V}; \_$_k$ ] ] ] ]
\draw[connect,shorten >=.5em,shorten <=.5em] (V/V.south east) [bend left] to (V/V.south west) ;
\draw[connect] (V/V.north east) [bend right] to (V'V.east);
\draw[connect] (V'V.north east) [bend right] to (S/V.east);
\draw[connect,shorten <=.5em] (S/V.north east) to [bend right] (V1) ;
\draw[connect] (V1) to [bend left] (V);
\end{tikzpicture}




\end{document}

Answer 2

Even with forest which can do a lot of things automatically, a certain amount of manual tweaking is needed. There is just no way for it to know what the content of the node means. However, forest does allow you to integrate the loops into the tree which may be attractive in some cases.

For example:

\documentclass[tikz,border=5pt]{standalone}
\usetikzlibrary{tikzmark, arrows.meta, bending}
\usepackage{forest}

\begin{document}

  \tikzset{
    connect/.style={{Stealth[bend]}-{Stealth[bend]}, draw=green, shorten <=-3pt, shorten >=-3pt}
  }
  \newlength\txtht
  \settoheight\txtht{B}
  \begin{forest}
    for tree={
      parent anchor=south,
      child anchor=north,
      if n children=0{tier=t, text height=\txtht}{},
    },
    [S
      [NP, tikz={\draw [connect] (.north east) [bend left] to ([xshift=-10pt]np1.north east);}
        [das Buch, triangle]
      ]
      [S/NP, name=np1, tikz={\draw [connect] (.east) [bend left] to ([xshift=-10pt]np2.north east);}
        [V (S//V), tikz={\draw [connect] ([xshift=-10pt].south east) [bend left] to (v1.north east);}
          [V, name=v1
            [liest$_k$]
          ]
        ]
        [S//V/NP, name=np2
          [NP/NP, tikz={\draw [connect] (.east) [bend right] to ([xshift=-10pt]np2.south east);}
            [-]
          ]
          [V$'$//V, tikz={\draw [connect] (.east) [bend left] to ([xshift=-5pt]v2.north east);}
            [NP
              [Jens]
            ]
            [V//V, name=v2, tikz={\draw [connect] ([xshift=5pt].south west) [out=-105, in=-75] to ([xshift=-5pt].south east);}
              [${}_{-k}$]
            ]
          ]
        ]
      ]
    ]
  \end{forest}

\end{document}