JFace Data Binding/Master Detail

Some UIs allow you to select an object from a list, table, or tree and then, based on the selection, allow you to edit details about the selected object. For example, the selected object could be a Person object, and the editable details could be the person's name and their phone number.

Usually, when creating a model-side observable, you call a method like BeansObservables.observeValue(person, "name"). This would create an observable that (behind the scenes) attaches a listener to the given person object so that it can generate standardized events when the name attribute changes.

When the selected person changes, you could dispose the observable (and the binding) for the previously selected person and create new ones for the newly selected person, but there is a better way. By creating a detail observable, you can keep the same observable and binding and what you would have done manually is done for you by the framework automatically.

To create a detail observable, first create an observable for the current selection (this is sometimes called the master observable), for example through ViewersObservables.observeSingleSelection(). Then, call BeansObservables.observeDetailValue(selectionObservable, "name", String.class) to create the detail observable for the currently selected person's name attibute.

For an example snippet, see the Master Detail snippet on the Snippets page.