proximitylistener.java

一个基于PlaceLab的室内和室外的智能导航系统

package javax.microedition.location;


/**
 * This interface represents a listener to events associated with detecting
 * proximity to some registered coordinates. Applications implement this
 * interface and register it with a static method in LocationProvider to obtain
 * notfications when proximity to registered coordinates is detected.
 * 
 * This listener is called when the terminal enters the proximity of the
 * registered coordinates. The proximity is defined as the proximity radius
 * around the coordinates combined with the horizontal accuracy of the current
 * sampled location.
 * 
 * The listener is called only once when the terminal enters the proximity of
 * the registered coordinates. The registration with these coordinates is
 * cancelled when the listener is called. If the application wants to be
 * notified again about these coordinates, it must re-register the coordinates
 * and the listener.
 * 
 */

public interface ProximityListener {

	/**
	 * After registering this listener with the LocationProvider, this method
	 * will be called by the platform when the implementation detects that the
	 * current location of the terminal is within the defined proximity radius
	 * of the registered coordinates.
	 * 
	 * @param coordinates
	 *            the registered coordinates to which proximity has been
	 *            detected
	 * @param location
	 *            the current location of the terminal
	 */
	public void proximityEvent(Coordinates coordinates, Location location);

	/**
	 * Called to notify that the state of the proximity monitoring has changed.
	 * 
	 * These state changes are delivered to the application as soon as possible
	 * after the state of the monitoring changes.
	 * 
	 * Regardless of the state, the ProximityListener remains registered until
	 * the application explicitly removes it with
	 * LocationProvider.removeProximityListener or the application exits.
	 * 
	 * These state changes may be related to state changes of some location
	 * providers, but this is implementation dependent as implementations can
	 * freely choose the method used to implement this proximity monitoring.
	 * 
	 * @param isMonitoringActive
	 *            a boolean indicating the new state of the proximity
	 *            monitoring. true indicates that the proximity monitoring is
	 *            active and false indicates that the proximity monitoring can't
	 *            be done currently.
	 */
	public void monitoringStateChanged(boolean isMonitoringActive);
}