It would help if we could see the relevant code and a small screenshot of the problem.
How would the system know about a change in the value of a function without calling that function continuously, in case the function depended on external state which might be as changeable as the weather?
That’s why we say that ofObject Bindings cannot depend on read-only properties – it’s the GraphObject property setter that detects when there has been a change in value and thus knows to re-evaluate any bindings.
For data bindings, it’s the Model method, such as Model.set, or a Model settable property, that knows how to update the appropriate Bindings.
I think Simon’s suggestion of implementing GraphObject.mouseEnter and mouseLeave event handlers might be the simplest solution.