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package com.blueturtle.orientexp;
 
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
 
public class OrientationListener implements SensorEventListener {
	private SensorManager olManager=null;
	private Sensor olSensor=null;
	private BTBase olContext=null;
	private float[] olOrientation = new float[3];
 
	// Constructor
	public OrientationListener(BTBase context, SensorManager man) {
		olContext=context;
		olManager = man;
		// Get a sensor
		olSensor = olManager.getDefaultSensor(
			Sensor.TYPE_MAGNETIC_FIELD);
		// Debug check, we do have a sensor, right? 
		// (Comment next two lines when you are tired of the dialog)
		olContext.shout("Orientation sensor", 
			"Orientation sensor name:\n"+olSensor.getName());
		// Enable the sensor
		enable();
	}
 
	// All we do when we enable the sensor is registering the listener
	public void enable() {
		olManager.registerListener(this, olSensor, 
			SensorManager.SENSOR_DELAY_GAME);
	}
 
	// And when we disable the sensor, we do it by 
	// unregistering the listener
	public void disable() {
		olManager.unregisterListener(this);
	}
 
	// Unused, but must be "implemented"
	public void onAccuracyChanged(Sensor arg0, int arg1) {
	}
 
	// Copy the sensor data to a local variable
	public void onSensorChanged(SensorEvent se) {
		for (int i=0; i<3; ++i) {
			olOrientation[i] = se.values[i];
		}
		olContext.update(BTBase.BTBASE_ORIENTATION);
	}
 
	// Return the current orientation to anyone who asks
	public float[] getOrienttation() {
		return olOrientation;
	}
}

package com.blueturtle.orientexp;
 
public interface BTBase {
	// Flags
	public int BTBASE_ORIENTATION=0x1; // Flag for orientation callbacks
	// Interface methods
	public void update(int flag);      // Callback
	public void shout(String title, String msg);  // Debug dialog
}

package com.blueturtle.orientexp;
 
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;
 
public class OrientExp extends Activity implements BTBase {
	private TextView myYaw=null;
	private TextView myPitch=null;
	private TextView myRoll=null;
	private OrientationListener myListener=null;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
 
        setContentView(R.layout.main);
        // Get references to the text views used to output the data
	// Defined in res/layout/main.xml
        myYaw = (TextView) findViewById(R.id.viewyaw);
        myPitch = (TextView) findViewById(R.id.viewpitch);
        myRoll = (TextView) findViewById(R.id.viewroll);
        // Create the listener (the second argument is this object retrieving
        // a sensor manager and passing it along)
        myListener = new OrientationListener(this, 
        	(SensorManager)getSystemService(Context.SENSOR_SERVICE));
    }
 
    public void update(int flags) {
   		// Get the data
		float[] data = myListener.getOrienttation();
  		// Update interface text
   		myYaw.setText("Yaw: "+ data[0]);
   		myPitch.setText("Pitch: "+data[1]);
   		myRoll.setText("Roll: "+data[2]);
    }
 
    // Create a message dialog for debug messages
    public void shout(String title, String msg) {
		AlertDialog.Builder dialog = new AlertDialog.Builder(this);
		dialog.setTitle(title);
		dialog.setMessage(msg);
		dialog.show();    	    	
    }
 
    // Disable the orientation sensors on pause
    public void onPause() {
    	super.onPause();
    	myListener.disable();
    }
 
    // And resume afterwards
    public void onResume() {
    	super.onResume();
    	myListener.enable();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:id="@+id/viewyaw" <!-- This id is what we use
            to identify the textview in OrientExp.java -->
    android:textSize="15pt"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Yaw: "
    />
<TextView  
    android:id="@+id/viewpitch"
    android:textSize="15pt"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Pitch: "
    />
<TextView  
    android:id="@+id/viewroll"
    android:textSize="15pt"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Roll: "
    />
</LinearLayout>