You want Bar to be passed a function to call, but not use it on construction, only on the callbacks from the GUI widget. That function must end up being an actual method somewhere (it's Java, ...

A callback operation in Java is one function that is passed to another function and executed after some action is completed. A callback can be executed either synchronously or asynchronously. In the ...

In a previous Java 101 tutorial, you learned how to better organize your code by declaring reference types (also known as classes and interfaces) as members of other reference types and blocks. I also ...