Making roofs smaller in tikz-qtree

Question

Is there a way to decrease the size of roofs in tikz-qtree? I want the roofs not to stick out but match the strings below them.

\documentclass{scrbook}

\usepackage{tikz}
\usepackage{tikz-qtree}

\begin{document}

\begin{tikzpicture}
\tikzset{level 1+/.style={level distance=4\baselineskip}}
\tikzset{frontier/.style={distance from root=16\baselineskip}}
\Tree[.{V[\begin{tabular}[t]{@{}l}
          {\sc comps} { },\\
          {\sc cont} {4}]\\
          \end{tabular}}
          [.{{1} NP{5}} man ]
          [.{V[\begin{tabular}[t]{@{}l}
               {\sc comps} { 1 },\\
               {\sc cont} {4}]\\
               \end{tabular}}
               [.{{2} NP{6}} \edge[roof]; ketābāro ]
               [.{V[\begin{tabular}[t]{@{}l}
                   {\sc comps} { {1}, {2} },\\
                   {\sc cont} {4}]\\
                   \end{tabular}}
                   [.{{3} PP{7}} \edge[roof]; {be Sepide} ]
                   [.{V[\begin{tabular}[t]{@{}l}
                        {\sc comps} { {1} NP{5}, {2} NP{6}, {3} PP{7}},\\
                        {\sc cont} {4} give({5}, {6}, {7})]\\
                        \end{tabular}} dādam ]
               ]
          ]
]
\end{tikzpicture}

\end{document}

Answer 1

Either you define your own roof style by mimicking the tikz-qtree.tex file and shifting the triangle corners with the current node inner sep amount or you specify the roof node options manually for each node.

\documentclass{article}
\usepackage{tikz-qtree}

\begin{document}

\begin{tikzpicture}[level 1+/.style={level distance=4\baselineskip},
frontier/.style={distance from root=16\baselineskip},
roof node/.append style={inner sep=0.1pt,text height=2ex,text depth=0.3ex}
]
\Tree[.{V[\begin{tabular}[t]{@{}l}
          {\sc comps} { },\\
          {\sc cont} {4}]\\
          \end{tabular}}
          [.{{1} NP{5}} man ]
          [.{V[\begin{tabular}[t]{@{}l}
               {\sc comps} { 1 },\\
               {\sc cont} {4}]\\
               \end{tabular}}
               [.{{2} NP{6}} \edge[roof]; \node[roof node]{ketābāro}; ]
               [.{V[\begin{tabular}[t]{@{}l}
                   {\sc comps} { {1}, {2} },\\
                   {\sc cont} {4}]\\
                   \end{tabular}}
                   [.{{3} PP{7}} \edge[roof]; \node[roof node]{be Sepide}; ]
                   [.{V[\begin{tabular}[t]{@{}l}
                        {\sc comps} { {1} NP{5}, {2} NP{6}, {3} PP{7}},\\
                        {\sc cont} {4} give({5}, {6}, {7})]\\
                        \end{tabular}} dādam ]
               ]
          ]
]
\end{tikzpicture}


\end{document}