Extended by view objects that wish to participate in an Editor hierarchy, but that do not implement the {@link Editor} contract directly. The primary advantage of the IsEditor interface is that is allows composition of behavior without the need to implement delegate methods for every interface implemented by the common editor logic. <p> For example, an editor Widget that supports adding and removing elements from a list might wish to re-use the provided {@link com.google.gwt.editor.client.adapters.ListEditor ListEditor} controller. It might be roughly built as:

class MyListEditor extends Composite implements IsEditor<ListEditor<Foo, FooEditor>> {
  private ListEditor<Foo, FooEditor> controller = ListEditor.of(new FooEditorSource());
  public ListEditor<Foo, FooEditor> asEditor() {return controller;}
  void onAddButtonClicked() { controller.getList().add(new Foo()); }
  void onClearButtonClicked() { controller.getList().clear(); }
}

By implementing only the one asEditor() method, the MyListEditor type is able to incorporate the ListEditor behavior without needing to write delegate methods for every method in ListEditor.

It is legal for a type to implement both Editor and IsEditor. In this case, the Editor returned from {@link #asEditor()} will be a co-Editor of the IsEditor instance.

@param <E> the type of Editor the view object will provide @see CompositeEditor

abstract class IsEditor<E> {

}