Events in Toolwindow Follow

Hi,

I would to make a toolwindow with a JPanel registered as view. In this plugin I would like to show some info on the currently editted Java file. Is there some event wich i can listen for that can help me keep the toolwindow in sync with the currently editted file?

I know how the obtain the currently editted file but not how I can do this automaticly when I select another file in the editor.