Controlling a web page from inside a program

The title isn't the best in the world so i'll try to be more specific and provide as many details as i can.

What i wanna do is have a web page displayed inside a Java Swing application and create a rectangle (or a panel) for each element that is on that web page (buttons, text fields etc.) and every time i move or resize the rectangle the corresponding element on the web page to change accordingly immediately. Can this be done and is it a good idea to refresh a web page that often? How else can i achieve this? For example how layout maker programs do this? Do they recreate the elements in the program instead of having them open up in a web page?

Thanks.