Design Strategy:

The key to this class is, obviously, the SwatchEngine. The parent (i.e., the container) has properties and methods to mirror the swatchengine (nStart, nStart, Start(), Stop(), Pause() and Resume()). This allows a form using the class to have a consistent interface to control the stopwatch (i.e., the form does not have to know that there are separate objects within the container—all the form has to do is communicate with the container.