/**
* Copyright (c) 2012-2013 Nokia Corporation. All rights reserved.
* Nokia and Nokia Connecting People are registered trademarks of Nokia Corporation.
* Oracle and Java are trademarks or registered trademarks of Oracle and/or its
* affiliates. Other product and company names mentioned herein may be trademarks
* or trade names of their respective owners.
* See LICENSE.TXT for license information.
*/
package com.nokia.example.battletank;
/*
* GameThread runs a game loop. This class is thread safe,
* cancel method is synchronized with calls to the Listener#runGameLoop.
*/
public class GameThread
extends Thread {
private boolean run = true;
private final Listener listener;
private final int fps;
/**
* Constructor
* @param listener
* @param fps listener.runGameLoop is called according to fps
*/
public GameThread(Listener listener, int fps) {
if (listener == null) {
throw new IllegalArgumentException("listener cannot be null");
}
if (fps <= 0) {
throw new IllegalArgumentException("fps must be bigger than 0");
}
this.listener = listener;
this.fps = fps;
}
/**
* @see Thread#run()
*/
public void run() {
long lastTime = 0;
while (run) {
long now = System.currentTimeMillis();
long delay = (1000 / fps) + lastTime - now;
if (delay < 1) {
delay = 1;
}
// force-sleep at least 1 ms to ensure time for the UI thread
try {
sleep(delay);
}
catch (InterruptedException e) {
}
if (run) {
runGameLoop();
}
lastTime = now;
}
}
private synchronized void runGameLoop() {
listener.runGameLoop();
}
/**
* Stop the game thread
*/
public synchronized void cancel() {
run = false;
}
/**
* Listener for a game thread.
*/
public interface Listener {
/**
* The game thread calls this method periodically
* until the thread is cancelled.
*/
void runGameLoop();
}
}