In this chapter, we will see how Vaadin widgets communicate with each other.
Widgets have to work together in order to achieve a common goal. Like ants, they cannot do so without a means to pass information. In Vaadin and other software, this is done through events and listeners.
In the first section of this chapter, we will explain this whole event and listener thing. We will have a look at the famous observer pattern and the way it is used in Java EE applications.
Then, we will get a grasp on how it is implemented in Vaadin and the different ways one can wire widgets together so one can be the subject and the other observers. A discussion will follow in order to determine which components category is the more suitable ...