001/**
002 * The MIT License (MIT)
003 *
004 * Copyright (c) 2019 nobark (tools4j), Marco Terzer, Anton Anufriev
005 *
006 * Permission is hereby granted, free of charge, to any person obtaining a copy
007 * of this software and associated documentation files (the "Software"), to deal
008 * in the Software without restriction, including without limitation the rights
009 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
010 * copies of the Software, and to permit persons to whom the Software is
011 * furnished to do so, subject to the following conditions:
012 *
013 * The above copyright notice and this permission notice shall be included in all
014 * copies or substantial portions of the Software.
015 *
016 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
017 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
018 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
019 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
020 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
021 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
022 * SOFTWARE.
023 */
024package org.tools4j.nobark.run;
025
026/**
027 * A factory for a {@link Runnable} that can be stopped by complying with a
028 * {@link RunnableFactory.RunningCondition RunningCondition} that is passed to the factory method upon construction of
029 * the runnable.
030 */
031@FunctionalInterface
032public interface RunnableFactory {
033
034    /**
035     * Creates a runnable that stops when the supplied {@code runningCondition} returns false.  THe runnable is expected
036     * to perform some iterative function and it is obliged to check the running condition regularly and return from the
037     * {@link Runnable#run() run()} method when the running condition returns false.
038     *
039     * @param runningCondition the condition to be checked regularly by the returned runnable telling it either to
040     *                         continue or to abort
041     * @return a new runnable that complies with the supplied running condition
042     */
043    Runnable create(RunningCondition runningCondition);
044
045    /**
046     * Condition for a runnable created by {@link RunnableFactory#create(RunningCondition)} telling the runnable when
047     * to stop.
048     */
049    @FunctionalInterface
050    interface RunningCondition {
051        /**
052         * Returns true if the runnable should continue its work and false if it should abort and return from te
053         * {@link Runnable#run() run()} method.
054         *
055         * @return true to keep running and false to abort
056         */
057        boolean keepRunning();
058    }
059}