Java tutorial
/* * 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(); }