How I find: What is focused.

Question

Hello:
 
Is there a service/control/whatever that can be running in a program and let me know what is focused?
 
Reason is: I would like to have something running that can update the statusBar with what is Focused. I know I can put code for each  object on Enter and on Leave. But I have many objects and I hate to put so much redundant code in the program.  Also I would like to write a routine that validates the field that is just left and go to the validation routine and if invalid go back to the field.    Am I dreaming, too much?