Making TikZ nodes hyperlinkable

Question

I have a TikZ tree. Now I want to make the nodes click-able directing to relevant sections in the document (or directed to URLs). Some of the content in the nodes are not text. Is it possible to turn the nodes into links, and if so, how? I would prefer the nodes themselves to be links, and not the text they contain.

Addition: I am not really good at it, and still learning, but here is a skeletal outline of the idea I am working on... (a graphical table of contents)

\documentclass{minimal} 
\usepackage{tikz}
\begin{document}

\begin{tikzpicture}
\tikzstyle{level 1}=[sibling distance=60mm]
\tikzstyle{level 2}=[sibling distance=25mm]

\node[circle,draw,grow=down] {\textbf{COOL TOC}}
    child {node {installation}
        child {node {Linux}}
        child {node {Mac}}
        child {node {Windows}}
    }
    child {node {Get Started}
        child {node {do A}}
        child {node {do B}}
    }
    child {node {Looking Further}
        child {node {manual}}
        child {node {online}}
    }
    child[grow=up] {node {troubleshoot}
        child {node {if X happens}}
        child {node {if Y happens}}
    };
\end{tikzpicture}

\end{document}

There are fancier examples for example this one would make for a great TOC.

Answer 1

Here's a new TikZ style called hyperlink node=<target> that takes a hypertarget reference. It works by measuring the node it is supplied to, and then placing a new invisible node on top of that. The new node has the content \hyperlink{<target>}{\phantom{\rule{<width of node>}{<height of node>}}, so it has the same size as the original node, but the whole area is clickable.

\documentclass{article}
\usepackage[hidelinks]{hyperref}
\usepackage{tikz}
\usetikzlibrary{calc}
\begin{document}
\tikzset{
    hyperlink node/.style={
        alias=sourcenode,
        append after command={
            let     \p1 = (sourcenode.north west),
                \p2=(sourcenode.south east),
                \n1={\x2-\x1},
                \n2={\y1-\y2} in
            node [inner sep=0pt, outer sep=0pt,anchor=north west,at=(\p1)] {\hyperlink{#1}{\phantom{\rule{\n1}{\n2}}}}
        }
    }
}

\tikz \node [draw, inner sep=2ex,hyperlink node=pagetwo] {Go to Page Two};

\clearpage
\hypertarget{pagetwo}{Page Two}
\end{document} 

Answer 2

Apart from Jake's nice idea – here's some code that works fine here in a recent document using the code from Drawing a directory listing a la the tree command in TikZ (answer of A. Stacey) and your MWE. It's not as fancy as your's, but maybe stylish, too.

\documentclass{article} 

\usepackage{tikz}
%------------------%
\makeatletter
\newcount\dirtree@lvl
\newcount\dirtree@plvl
\newcount\dirtree@clvl
\def\dirtree@growth{%
  \ifnum\tikznumberofcurrentchild=1\relax
  \global\advance\dirtree@plvl by 1
  \expandafter\xdef\csname dirtree@p@\the\dirtree@plvl\endcsname{\the\dirtree@lvl}
  \fi
  \global\advance\dirtree@lvl by 1\relax
  \dirtree@clvl=\dirtree@lvl
  \advance\dirtree@clvl by -\csname dirtree@p@\the\dirtree@plvl\endcsname
  \pgf@xa=0.5cm\relax % change the length to your needs
  \pgf@ya=-0.75cm\relax % change the length to your needs
  \pgf@ya=\dirtree@clvl\pgf@ya
  \pgftransformshift{\pgfqpoint{\the\pgf@xa}{\the\pgf@ya}}%
  \ifnum\tikznumberofcurrentchild=\tikznumberofchildren
  \global\advance\dirtree@plvl by -1
  \fi
}
\tikzset{ %definition of a new style "dirtree"
  dirtree/.style={
    growth function=\dirtree@growth,
    every node/.style={anchor=north},
    every child node/.style={anchor=west},
    edge from parent path={(\tikzparentnode\tikzparentanchor) |- (\tikzchildnode\tikzchildanchor)}
  }
}
\makeatother
%------------------%

\usepackage{hyperref}

\begin{document}

\begin{tikzpicture}[dirtree] % it's what we defined above

\node {\textbf{COOL TOC}}
    child { node {\hyperref[install]{installation} }
        child { node {\hyperref[linux]{Linux}} }
        child { node {\hyperref[mac]{Mac}} }
        child { node {\hyperref[win]{Windows}} }
    }
    child {node {\hyperref[start]{Get Started}}
        child { node {\hyperref[caseA]{do A}} }
        child { node {\hyperref[caseB]{do B}} }
    }
    child {node {\hyperref[trbl-shoot]{troubleshoot}}
        child {node {\hyperref[caseX]{if X happens}}}
        child {node {\hyperref[caseY]{if Y happens}}}
    }
    % I've put the external resources to the end:
    child {node {Looking Further}
        child { node {\href{file:manual.pdf}{manual}} }% works only, if "manual.pdf" is in
                                                       % the same directory as the compiled
                                                       % version of this document
        child { node {\href{http://website.example.com/online-resource/}{online}} }
    };
\end{tikzpicture}

\section*{Installation}\label{install}
\subsection*{Linux}\label{linux}
Some content.

\subsection*{Mac}\label{mac}
Some content.

\subsection*{Windows}\label{win}
Some content.

\section*{Get started}\label{start}
\subsection*{First: Do A}\label{caseA}
Some content.

\subsection*{Second: Do B}\label{caseB}
 Some content.

\section*{Trouble shooting}\label{trbl-shoot}
\subsection*{If X happens:}\label{caseX}
Some content.

\subsection*{If Y happens:}\label{caseY}
 Some content.

 \end{document}