/*
* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.editor.client;
/**
* 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:
*
* <pre>
* 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(); }
* }
* </pre>
* By implementing only the one <code>asEditor()</code> method, the
* <code>MyListEditor</code> type is able to incorporate the
* <code>ListEditor</code> behavior without needing to write delegate methods
* for every method in <code>ListEditor</code>.
* <p>
* 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
*/
public interface IsEditor<E extends Editor<?>> {
/**
* Returns the Editor encapsulated by the view object.
*
* @return an {@link Editor} of type E
*/
E asEditor();
}