PlotSquared/Core/src/main/java/com/plotsquared/core/util/task/PlotSquaredTask.java

/*
 *       _____  _       _    _____                                _
 *      |  __ \| |     | |  / ____|                              | |
 *      | |__) | | ___ | |_| (___   __ _ _   _  __ _ _ __ ___  __| |
 *      |  ___/| |/ _ \| __|\___ \ / _` | | | |/ _` | '__/ _ \/ _` |
 *      | |    | | (_) | |_ ____) | (_| | |_| | (_| | | |  __/ (_| |
 *      |_|    |_|\___/ \__|_____/ \__, |\__,_|\__,_|_|  \___|\__,_|
 *                                    | |
 *                                    |_|
 *            PlotSquared plot management system for Minecraft
 *                  Copyright (C) 2021 IntellectualSites
 *
 *     This program is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     This program 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 for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
package com.plotsquared.core.util.task;

/**
 * A task that can be run and cancelled (if repeating)
 */
public interface PlotSquaredTask extends Runnable {

    /**
     * Get a new {@link NullTask}
     *
     * @return Null task instance
     */
    static NullTask nullTask() {
        return new NullTask();
    }

    /**
     * Run the task. Don't override this, instead
     * implement {@link #runTask()}
     */
    @Override
    default void run() {
        if (isCancelled()) {
            return;
        }
        this.runTask();
    }

    /**
     * Run the task
     */
    void runTask();

    /**
     * Check if the task has been cancelled
     *
     * @return {@code true} if the tasks is cancelled,
     * {@code false} if not
     */
    boolean isCancelled();

    /**
     * Cancel the task
     */
    void cancel();

    /**
     * Task that does nothing and is always cancelled
     */
    class NullTask implements PlotSquaredTask {

        @Override
        public void runTask() {
        }

        @Override
        public boolean isCancelled() {
            return true;
        }

        @Override
        public void cancel() {
        }

    }

}