src/net/lightstone/task/Task.java

/*
 * Copyright (c) 2010-2011 Graham Edgecombe.
 *
 * This file is part of Lightstone.
 *
 * Lightstone 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.
 *
 * Lightstone 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 Lightstone.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.lightstone.task;

/**
 * Represents a task which is executed periodically.
 * @author Graham Edgecombe
 */
public abstract class Task {

	/**
	 * The number of ticks between calls to the {@link #execute()} method.
	 */
	private int ticks;
	
	/**
	 * The current count of remaining ticks.
	 */
	private int counter;
	
	/**
	 * A flag which indicates if this task is running.
	 */
	private boolean running = true;

	/**
	 * Creates a new task with the specified number of ticks between
	 * consecutive calls to {@link #execute()}.
	 * @param ticks The number of ticks.
	 */
	public Task(int ticks) {
		this.ticks = ticks;
		this.counter = ticks;
	}

	/**
	 * Sets the number of ticks.
	 * @param ticks The number of ticks.
	 */
	public void setTicks(int ticks) {
		this.ticks = ticks;
	}

	/**
	 * Stops this task.
	 */
	public void stop() {
		running = false;
	}

	/**
	 * Checks if this task is running.
	 * @return {@code true} if so, {@code false} if not.
	 */
	public boolean isRunning() {
		return running;
	}

	/**
	 * Checks if this task has stopped.
	 * @return {@code true} if so, {@code false} if not.
	 */
	public boolean isStopped() {
		return !running;
	}

	/**
	 * Called when this task should be executed.
	 */
	public abstract void execute();

	/**
	 * Called every 'pulse' which is around 200ms in Minecraft. This method
	 * updates the counters and calls {@link #execute()} if necessary.
	 * @return The {@link #isRunning()} flag.
	 */
	boolean pulse() {
		if (!running)
			return false;

		if (--counter == 0) {
			counter = ticks;
			execute();
		}

		return running;
	}

}