ScreenSensor.java

package interdroid.swan.sensors.impl;

import interdroid.swan.R;
import interdroid.swan.sensors.AbstractConfigurationActivity;
import interdroid.swan.sensors.AbstractSwanSensor;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.PowerManager;

/**
 * A sensor for if the screen is on or off.
 * 
 * @author nick <palmer@cs.vu.nl>
 * 
 */
public class ScreenSensor extends AbstractSwanSensor {
	public static final String TAG = "ScreenSensor";
	/**
	 * The configuration activity for this sensor.
	 * 
	 * @author nick <palmer@cs.vu.nl>
	 * 
	 */
	public static class ConfigurationActivity extends
			AbstractConfigurationActivity {

		@Override
		public final int getPreferencesXML() {
			return R.xml.screen_preferences;
		}

	}

	/**
	 * Is screen on field.
	 */
	public static final String IS_SCREEN_ON_FIELD = "is_screen_on";

	/**
	 * The receiver of screen information.
	 */
	private BroadcastReceiver screenReceiver = new BroadcastReceiver() {

		@Override
		public void onReceive(final Context context, final Intent intent) {
			long now = System.currentTimeMillis();

			if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
				putValueTrimSize(IS_SCREEN_ON_FIELD, null, now, "false");
			} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
				putValueTrimSize(IS_SCREEN_ON_FIELD, null, now, "true");
			}
		}

	};

	@Override
	public final String[] getValuePaths() {
		return new String[] { IS_SCREEN_ON_FIELD };
	}

	@Override
	public void initDefaultConfiguration(final Bundle defaults) {
	}

	@Override
	public final void onConnected() {
		SENSOR_NAME = "Screen Sensor";
	}

	@Override
	public final void register(final String id, final String valuePath,
			final Bundle configuration) {
		if (registeredConfigurations.size() == 1) {
			PowerManager pm = (PowerManager) getSystemService(POWER_SERVICE);
			putValueTrimSize(IS_SCREEN_ON_FIELD, null, System.currentTimeMillis(), pm.isScreenOn());
			
			IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
			filter.addAction(Intent.ACTION_SCREEN_OFF);
			registerReceiver(screenReceiver, filter);
		}
	}

	@Override
	public final void unregister(final String id) {
		if (registeredConfigurations.size() == 0) {
			unregisterReceiver(screenReceiver);
		}
	}

	@Override
	public final void onDestroySensor() {
		unregisterReceiver(screenReceiver);
		super.onDestroySensor();
	}

}