Java tutorial
/* * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javafx.util; /** * The Callback interface is designed to allow for a common, reusable interface * to exist for defining APIs that requires a call back in certain situations. * <p> * Callback is defined with two generic parameters: the first parameter * specifies the type of the object passed in to the <code>call</code> method, * with the second parameter specifying the return type of the method. * * @param <P> The type of the argument provided to the <code>call</code> method. * @param <R> The type of the return type of the <code>call</code> method. * @since JavaFX 2.0 */ @FunctionalInterface public interface Callback<P, R> { /** * The <code>call</code> method is called when required, and is given a * single argument of type P, with a requirement that an object of type R * is returned. * * @param param The single argument upon which the returned value should be * determined. * @return An object of type R that may be determined based on the provided * parameter value. */ public R call(P param); }