Newbee Question

Hi I am fairly new to SVG and Batik.
I am thinking of using the Batik framework in an application I write and I
want to know if it is possible to achieve my needs with Batik.

Lets assume I generate an svg showing the graphical representation of a
Binary tree.

Now I need following behavior.

1.If a certain condition in a separate program(not the batik viewer
component) is reached I want to change the color or a circle in my svg
image.
2. if I click on a circle in my svg image I need to inform this separate
program that circle  "foo" is clicked.

Is this possible with batik and svg? And how do I archive this?
Would be nice if someone could help me with this or point me to where I can
find this information.

Thanks in advance

Ralf