[Tex/LaTex] Drawing a circle around a node that looks like an arrow

arrowstikz-pgf

So I'm using TikZ, not too well-versed in it, and I would like to draw a node (unlabeled, just a dot) and with a dashed circle around it that has an arrow on it (this indicates direction). Basically something like this:

http://s8.postimage.org/4ua9e2ftf/Untitled_2.jpg

So far what I figure I could do: make the node, which I have as 

\node[style={circle,draw=black,inner sep=1.4pt,fill}] (a) at (0,0) {};

And then make a circle

\node[style={circle,dashed,draw=black, very thick,inner sep=5pt}] (b) at (0,0) {};

And then I'm not sure how to add the arrow end on that circle, and I was hoping you guys could help!

It would be swell if all this could be done with a single instance of a node (in the text), but any help at all is appreciated.

Best Answer

A simple adaptation of How to put a symbol inside a circle arrow? yields the desired result (blue circle). However, if you are doing this in a tikzpicture you can just draw it directly (red circle):

enter image description here

Code:

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz}
\usepackage{calc}

\makeatletter
\newlength\@SizeOfCirc%
\newcommand{\CricArrowRight}[2][]{%
    \setlength{\@SizeOfCirc}{\maxof{\widthof{#2}}{\heightof{#2}}}%
    \tikz [x=1.0ex,y=1.0ex,line width=.15ex, draw=blue, #1]%
        \draw [->,anchor=center, densely dashed]%
            node (0,0) {#2}%
            (0,1.2\@SizeOfCirc) arc (85:-240:1.2\@SizeOfCirc);%
}%

\makeatother

\begin{document}
    \CricArrowRight{$\cdot$}
    %
    \begin{tikzpicture}
    \draw [fill=blue, draw=blue] (0,0) circle (1.5pt);
    
    \draw [->,anchor=center, densely dashed, thick, draw=red]
        (85:0.25cm)  arc (85:-240:0.25cm);
    \end{tikzpicture}
\end{document}
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