Brew MP 1.0.2
This function allows objects such as widgets and UI controls to attach a listener to the given
value model. The listener includes a callback function that BREW will call whenever the model has
changed state, thereby notifying the owner of the listener that data has changed. To illustrate,
consider a widget that displays the current charge of battery. The widget itself is responsible
for displaying battery charge, while the value of the charge would be managed by a value model
that receives updates from the device as battery strength changes. The battery widget would register
as a listener for the battery model by calling IVALUEMODEL_AddListener(). As the model learns of changes
to the battery charge, the value model would send out notifications to any registered object -- in this
case, to the battery widget, which could then redraw itself to accurately portray battery strength.
Pointer to the IValueModel interface object.
Pointer to the ModelListener that will be attached to the object. The ModelListener will
contain the PFNLISTENER callback function BREW will call to notify the registering object
of changes to the value model.