\documentclass{article}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{tikz}
\usetikzlibrary{trees}
\usepackage[dvipsnames]{xcolor}
\usepackage{verbatimbox}
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{5pt}
\begin{document}
	\tikzstyle{every node}=[draw=black,thick,anchor=west]
	\tikzstyle{selected}=[draw=red,fill=red!30]
	\tikzstyle{foot}=[fill=gray!50]
	\tikzstyle{rel}=[draw=Blue,fill=ProcessBlue!50]
	\tikzstyle{partition}=[draw=white]

	\begin{tikzpicture}[%
		grow via three points={one child at (0.5,-0.7) and
			two children at (0.5,-0.7) and (0.5,-1.4)},
		edge from parent path={(\tikzparentnode.south) |- (\tikzchildnode.west)}]
		\node  [foot] { latex-skript }
		child { node [rel] { main-exercises.tex} }
		child { node [selected] { praeamble.tex}}
		% child { node { listings}}
		child {node {content} 
			child { node { basic-document-structure.tex}}
			child { node { basic-functionality.tex}}
			child { node { ... }}
		}
		child [missing] {}
		child [missing] {}
		child [missing] {}
		child { node {exercises}
			child { node { graphics }
				child { node {graphics.raw.tex}}
				child { node {task.tex }}
				child { node {...}}}
			child [missing] {}
			child [missing] {}
			child [missing] {}
			child { node { … }}
		};
		% child [missing] {}
		% child [missing] {}
		% child [missing] {}
		% child [missing] {}
		% child [missing] {}
		% child [missing] {}
		% child [missing] {}
		% child [missing] {}
		% child { node {...}};
		\end{tikzpicture}

\end{document}