com.algorithmstudy.visualizer.client.sort.VisualizerTimerImpl.java Source code

Introduction

Here is the source code for com.algorithmstudy.visualizer.client.sort.VisualizerTimerImpl.java

Source

/*
 * Copyright (C) 2009 The Algorithm Study Project
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2.0 as published by the Free Software Foundation.
 *
 * 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 version
 * 2.0 along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 * or find it on the GNU website at:
 *
 *    http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */
package com.algorithmstudy.visualizer.client.sort;

import java.util.ArrayList;

import com.algorithmstudy.visualizer.client.model.Visualizer;
import com.algorithmstudy.visualizer.client.model.VisualizerTimer;
import com.google.gwt.user.client.Timer;

/**
 * A timer class that calls back to the list of visualizers.
 */
public class VisualizerTimerImpl implements VisualizerTimer {

    public static final int MULTIPLIER_DEFAULT = 50;
    public static final int MULTIPLIER_HIGH = 100;
    public static final int MULTIPLIER_LOW = 1;

    private static final int DELAY_BASE = 5;

    /** The list of visualizers. */
    private ArrayList<Visualizer> visualizers = new ArrayList<Visualizer>();

    private int tickMultiplier = MULTIPLIER_DEFAULT;

    private Timer theTimer;

    public void addVisualizer(Visualizer v) {
        visualizers.add(v);
    }

    public void clearVisualizerList() {
        visualizers.clear();
    }

    public void removeVisualizer(Visualizer v) {
        visualizers.remove(v);
    }

    public void setTickMultiplier(int tickMultiplier) {
        if (MULTIPLIER_LOW > tickMultiplier) {
            this.tickMultiplier = MULTIPLIER_LOW;
        } else if (MULTIPLIER_HIGH < tickMultiplier) {
            this.tickMultiplier = MULTIPLIER_HIGH;
        } else {
            this.tickMultiplier = tickMultiplier;
        }
    }

    public void start() {
        if (null != theTimer) {
            System.out.println("VisualizerTimer.start() called but timer is already running.");
            return;
        }

        theTimer = new Timer() {
            public void run() {
                sendTick();
            }
        };

        schedule();
    }

    public void stop() {
        if (null == theTimer) {
            System.out.println("VisualizerTimer.stopt() called but timer is not running.");
            return;
        }

        theTimer.cancel();
        theTimer = null;
    }

    /**
     * Schedule the timer.
     */
    private void schedule() {
        theTimer.schedule(DELAY_BASE * tickMultiplier);
    }

    /**
     * Callback to send a tick to all the visualizers.
     */
    private void sendTick() {
        boolean keepGoing = false;
        for (Visualizer v : visualizers) {
            if (v.tick()) {
                keepGoing = true;
            }
        }

        if (keepGoing) {
            schedule();
        }
    }

}