Specifying The Behavior Of Graphical Objects Using Esterel

Specifying the behavior of graphical objects, such as menus, scrollbars, etc. is not an easy task. This is because one must deal with multiple input devices such as the mouse and keyboard. This makes the specification of such objects difficult to write and hard to maintain. We consider these objects as reactive systems that receive inputs and generate output after updating their internal state. We present here how one can use the Esterel language to write efficient, clean, and modular specifications of such systems. Esterel also provides for the reuseability of such specifications.