Doxygen dot. Draw link between classes by annotati

Question

Doxygen can generate class diagrams with graphiz.

For example:

class A {...};
class B extends A {...};

From this code I can generate a picture where doxygen can show that one class it the parent of an other.

But is there a way to generate a picture from code with manual references between classes?

For example when I describe DB scheme and use contract classes (http://developer.android.com/training/basics/data-storage/databases.html#DefineContract) I want to perform smth like this:

class MainClass {
    class A {
        String COLUMN_ID = "id_a";
    }

    /**
     * {@dotlinkto MainClass.A}
    **/
    @OrAnotationToDrawLink(A.class)
    class B {
        String COLUMN_ID = "id_b";
        String COLUMN_FOREIGN_KEY_TO_A = "id_a_key";
    }
}

And generate a picture of 2 classes A and B with reference between them.

I've tried to search through documentation but can't find any suitable examples or explanation about custom drawing in javadoc+doxygen+graphviz.

Answer 1

The closest thing I can think of is to define a custom command that expands to an inline dot graph, i.e.

class MainClass {
  public class A {
    String COLUMN_ID = "id_a";
  }

  /**
   * @dotlinkbetween{A,B}
   * @cond
   **/
   @OrAnotationToDrawLink(A.class)
  /** @endcond */
   public class B {
      String COLUMN_ID = "id_b";
      String COLUMN_FOREIGN_KEY_TO_A = "id_a_key";
    }
}

with the following ALIAS definition in doxygen's configuration file:

ALIASES = dotlinkbetween{2}="@dot digraph { node [shape=record ]; \1 [ URL=\"\ref \1\" ]; \2 [ URL=\"\ref \2\" ]; \2 -> \1; } @enddot"

note that I had to use @cond ... @endcond to let doxygen skip the @OrAnotationToDrawLink line.