Is there a library for drawing object inheritance trees in TikZ?

Question

This seems like a very common thing, but searching for the words 'tree', 'language', 'object', 'inheritance' and/or 'parent' returns Questions that have nothing to do with mine.

In a nutshell, I want this:

But if instead of class B-D I have B-V, I would rather not go in and manually move everything around. Currently, I am using nodes and my classes are flying off the page.

What is one/any way to tackle this problem.

MWE:

\usepackage{tikz}
\usetikzlibrary{arrows,decorations.pathmorphing,backgrounds,positioning,fit,petri,calc,shadows}
\begin{document}
    \begin{tikzpicture}[
        neuronModel/.style={%
            general shadow={%
                shadow scale=1,
                shadow xshift=0.75ex,
                shadow yshift=0.75ex,
                opacity=0.75,
                fill=black!50,
                every shadow
            },
            rounded corners,
            thick,
            draw=blue!90,
            fill=blue!35,
            thick,
            inner ysep=2pt,
            inner xsep=2pt
        }]

        % \foreach \neuronIndex/\neuronLabel in {1/Bidirectional Neuron Model , 10/Unidirectional Neuron Model}
            % \node at (\neuronIndex,10)[draw=black,fill=blue]{\neuronLabel};

        \node[neuronModel,align=center] (neuronModel1) {Bidirectional\\
                                                                                    Neuron Model};
        \node[neuronModel,right=0.5cm of neuronModel1,align=center] (neuronModel2) {Unidirectional\\
                                                                                    Neuron Model};
        \node[neuronModel,right=0.5cm of neuronModel2,align=center] (neuronModel3) {Postprocessing\\
                                                                                    Neuron Model};
        \node[neuronModel,right=0.5cm of neuronModel3,align=center] (neuronModel4) {Preprocessing\\
                                                                                    Neuron Model};
        \node[neuronModel,right=0.5cm of neuronModel4,align=center] (neuronModel5) {Stats\\
                                                                                    Neuron Model};
        \node[neuronModel,right=0.5cm of neuronModel5,align=center] (neuronModel6) {Visual\\
                                                                                    Neuron Model};
    \end{tikzpicture}
\end{document}

Here is the resulting picture. I need to add about 5 more classes, so this approach will not suffice.

Answer 1

The tikz-qtree package can probably do what you want. Here is a crude example:

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

\begin{document}

\begin{tikzpicture}
\tikzset{level distance=50pt}
\Tree [.\node[draw]{class A};
    [.\node[draw]{class B}; ]
    [.\node[draw]{class C}; ]
    [.\node[draw]{class D};
        \node[draw]{class E};
    ]
]
\end{tikzpicture}

\end{document}

As pointed out by Alan Munn, the code can be further simplified by specifying the node style in advance:

\begin{tikzpicture}[every tree node/.style=draw]
\tikzset{level distance=50pt}
\Tree [.{class A}
    [.{class B} ]
    [.{class C} ]
    [.{class D}
        {class E}
    ]
]
\end{tikzpicture}