An Android Game Development Framework - Beginning Android Games - page 200

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// nothing to do here
}
@Override
public void onSensorChanged(SensorEvent event) {
yaw=event.values[0];
pitch=event.values[1];
roll=event.values[2];
}
public float getYaw() {
return yaw;
}
public float getPitch() {
return pitch;
}
public float getRoll() {
return roll;
}
}
We won't use the compass in any of the games in this topic, but if you are going to reuse the
framework we develop, this class might come in handy.
The Pool Class: Because Reuse Is Good for You!
What's the worst thing that can happen to us as Android developers? World-stopping
garbage collection! If you look at the Input interface definition in Chapter 3, you'll find the
getTouchEvents() and getKeyEvents() methods. These methods return TouchEvent and
KeyEvent lists. In our keyboard and touch event handlers, we constantly create instances of
these two classes and store them in lists that are internal to the handlers. The Android input
system fires many of these events when a key is pressed or a finger touches the screen, so we
constantly create new instances that are collected by the garbage collector in short intervals. In
order to avoid this, we implement a concept known as instance pooling . Instead of repeatedly
creating new instances of a class, we simply reuse previously created instances. The Pool class
is a convenient way to implement that behavior. Let's have a look at its code in Listing 5-7, which
is broken up again, containing appropriate commentary.
Listing 5-7. Pool.java; Playing Well with the Garbage Collector
package com.badlogic.androidgames.framework;
import java.util.ArrayList;
import java.util.List;
public class Pool<T> {