[Tex/LaTex] Create legend tikzpicture without pgfplots

legendtikz-pgf

I already tried to create a legend with pgfplots but it seems that conflicts with tikz-uml library (another tikzpicture that I have in the same file) so I want to know how can I create a legend with this example (taken from http://www.woggie.net/2012/07/16/drawing-feature-models-in-pgf-tikz/):

\documentclass[tikz]{standalone}
\usetikzlibrary{matrix,arrows,positioning,shadows}
\tikzset{
    feature/.style={draw, inner sep=1.5mm, font=\small\sffamily, fill=white, drop shadow},
    opt/.style={fill=white}}

\begin{document}

\begin{tikzpicture}[node distance=.8cm]
  \node[feature] (phone) {Phone};

  \matrix (sub)[matrix of nodes,
                below=of phone,
                column sep=3mm, row sep=0mm, nodes=feature]{
  Processor & %sub-1-1
  NFC & %sub-1-2
  Camera & %sub-1-3
  4G \\ %sub-1-4
  };

  \matrix (group)[matrix of nodes, 
                  below=of sub-1-1,
                  column sep=3mm, row sep=0mm, nodes=feature]{
  ARM & %group-1-1
  OMAP & %group-1-2
  Snapdragon \\ %group-1-3
  };

  \draw (phone.south) -- (sub-1-1.north);
  \draw (phone.south) -- (sub-1-2.north);
  \draw (phone.south) -- (sub-1-3.north);
  \draw (phone.south) -- (sub-1-4.north);

  \draw (sub-1-1.south) -- (group-1-1);
  \draw (sub-1-1.south) -- (group-1-2);
  \draw (sub-1-1.south) -- (group-1-3);

  %cross-tree constraint
  \draw[-triangle 45,dashed] (sub-1-4) |- (group-1-3)
    node[pos=.6,anchor=south east] {implies};

  %optional / mandatory
  \draw[opt] (sub-1-2.north) circle (.8mm); 
  \draw[opt] (sub-1-4.north) circle (.8mm); 
  \fill[draw] (sub-1-1.north) circle (.8mm); 
  \fill[draw] (sub-1-3.north) circle (.8mm); 

  %Group arc
  \begin{scope}
    \path[clip] (sub-1-1.south) -- (group-1-1.center) -- (group-1-3.center) -- cycle;
    \draw (sub-1-1.south) circle (.5cm);
  \end{scope}
\end{tikzpicture}

\end{document}

The idea is to create a legend at the top right like this example (taken from wikipedia) enter image description here

Can anyone help me? Thank you!

Best Answer

For lack of better solutions, one can always make it manually, for example with a \matrix:

\matrix [draw=black,fill=brown!20,left=1.5cm of phone] {
  \node[fill=black,draw,circle,inner sep=2pt,outer sep=0pt] (m) at (0,0){}; \draw (m) -- +(0,0.4); & \node[legendtext]{Mandatory}; & 
   \filldraw[fill=white,draw=black] (0,0.2) -- ++(225:0.2) arc[start angle=225,end angle=315,radius=0.2]; 
 \draw (0,0.2) ++(225:0.5) -- (0,0.2) -- ++(315:0.5);& \node[legendtext]{Alternative}; \\
  \node[fill=white,draw=black,circle,inner sep=2pt,outer sep=0pt] (o) at (0,0){}; \draw (m) -- +(0,0.4); & \node[legendtext]{Optional}; & 
  \draw (0,0.2) ++(225:0.5) -- (0,0.2) -- ++(315:0.5);
  \filldraw[black] (0,0.2) -- ++(225:0.2) arc[start angle=225,end angle=315,radius=0.2]; & \node[legendtext]{Or}; 
\\
};

I see there is no Or in your diagram, but I included it for good measure. Commenting out the last \draw and \filldraw in the above matrix removes that. The legendtext style just has text width=2cm, and is defined in the options to the tikzpicture, see complete code below.

enter image description here

\documentclass[tikz,border=4mm]{standalone}
\usetikzlibrary{matrix,arrows,positioning,shadows}
\tikzset{
    feature/.style={draw, inner sep=1.5mm, font=\small\sffamily, fill=white, drop shadow},
    opt/.style={fill=white}}

\begin{document}

\begin{tikzpicture}[
  node distance=.8cm,
  legendtext/.style={text width=2cm}]
  \node[feature] (phone) {Phone};

  \matrix (sub)[matrix of nodes,
                below=of phone,
                column sep=3mm, row sep=0mm, nodes=feature]{
  Processor & %sub-1-1
  NFC & %sub-1-2
  Camera & %sub-1-3
  4G \\ %sub-1-4
  };

  \matrix (group)[matrix of nodes, 
                  below=of sub-1-1,
                  column sep=3mm, row sep=0mm, nodes=feature]{
  ARM & %group-1-1
  OMAP & %group-1-2
  Snapdragon \\ %group-1-3
  };

  \draw (phone.south) -- (sub-1-1.north);
  \draw (phone.south) -- (sub-1-2.north);
  \draw (phone.south) -- (sub-1-3.north);
  \draw (phone.south) -- (sub-1-4.north);

  \draw (sub-1-1.south) -- (group-1-1);
  \draw (sub-1-1.south) -- (group-1-2);
  \draw (sub-1-1.south) -- (group-1-3);

  %cross-tree constraint
  \draw[-triangle 45,dashed] (sub-1-4) |- (group-1-3)
    node[pos=.6,anchor=south east] {implies};

  %optional / mandatory
  \draw[opt] (sub-1-2.north) circle (.8mm); 
  \draw[opt] (sub-1-4.north) circle (.8mm); 
  \fill[draw] (sub-1-1.north) circle (.8mm); 
  \fill[draw] (sub-1-3.north) circle (.8mm); 

  %Group arc
  \begin{scope}
    \path[clip] (sub-1-1.south) -- (group-1-1.center) -- (group-1-3.center) -- cycle;
    \draw (sub-1-1.south) circle (.5cm);
  \end{scope}

\matrix [draw=black,fill=brown!20,left=1.5cm of phone] {
  \node[fill=black,draw,circle,inner sep=2pt,outer sep=0pt] (m) at (0,0){}; \draw (m) -- +(0,0.4); & \node[legendtext]{Mandatory}; & 
   \filldraw[fill=white,draw=black] (0,0.2) -- ++(225:0.2) arc[start angle=225,end angle=315,radius=0.2]; 
 \draw (0,0.2) ++(225:0.5) -- (0,0.2) -- ++(315:0.5);& \node[legendtext]{Alternative}; \\
  \node[fill=white,draw=black,circle,inner sep=2pt,outer sep=0pt] (o) at (0,0){}; \draw (m) -- +(0,0.4); & \node[legendtext]{Optional}; & 
  \draw (0,0.2) ++(225:0.5) -- (0,0.2) -- ++(315:0.5);
  \filldraw[black] (0,0.2) -- ++(225:0.2) arc[start angle=225,end angle=315,radius=0.2]; & \node[legendtext]{Or}; 
\\
};
\end{tikzpicture}
\end{document}
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