/*
* Copyright (c) 2005-2010 KOM – Multimedia Communications Lab
*
* This file is part of PeerfactSim.KOM.
*
* PeerfactSim.KOM is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* any later version.
*
* PeerfactSim.KOM is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with PeerfactSim.KOM. If not, see .
*
*/
package de.tud.kom.p2psim.impl.topology;
import java.util.LinkedList;
import java.util.List;
import de.tud.kom.p2psim.api.common.SimHost;
import de.tud.kom.p2psim.impl.simengine.Simulator;
import de.tudarmstadt.maki.simonstrator.api.Event;
import de.tudarmstadt.maki.simonstrator.api.EventHandler;
import de.tudarmstadt.maki.simonstrator.api.component.sensor.location.Location;
import de.tudarmstadt.maki.simonstrator.api.component.sensor.location.LocationListener;
import de.tudarmstadt.maki.simonstrator.api.component.sensor.location.LocationRequest;
import de.tudarmstadt.maki.simonstrator.api.component.sensor.location.LocationSensor;
/**
* Update 15.03.16 added support for multiple listeners (however, frequency
* etc. is immune after the first request is registered.)
*
* @author Bjoern Richerzhagen
* @version 1.0, Mar 15, 2016
*/
public class LocationRequestImpl implements LocationRequest, EventHandler {
private boolean immune = false;
private long interval = 1 * Simulator.MINUTE_UNIT;
private int priority = LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY;
private Location lastLocation = null;
private List listeners = new LinkedList();
private int eventTypeSeq = 0;
private SimHost host;
private LocationSensor locationSensor;
public LocationRequestImpl(SimHost host, LocationSensor locationSensor) {
this.host = host;
this.locationSensor = locationSensor;
}
protected void cancel(LocationListener listener) {
boolean removed = listeners.remove(listener);
if (listeners.isEmpty()) {
// upcoming event is no longer valid!
eventTypeSeq++;
}
assert removed;
}
protected void immunizeAndStart(LocationListener listener) {
immune = true;
assert interval > 0;
if (listeners.isEmpty()) {
// Only start once!
lastLocation = null;
Event.scheduleImmediately(this, null, eventTypeSeq);
} else {
// Fire each new listener at least once
listener.onLocationChanged(host, locationSensor.getLastLocation());
}
listeners.add(listener);
}
@Override
public void setInterval(long interval) {
if (!immune) {
this.interval = interval;
}
}
@Override
public void setPriority(int priority) {
if (!immune) {
this.priority = priority;
}
}
@Override
public void eventOccurred(Object content, int type) {
if (eventTypeSeq != type) {
/*
* Discard invalid events caused when a client cancels updates
* but reactivates the request within the update frequency
* interval. In this case, the old events continue rescheduling
* themselves.
*/
return;
}
if (!listeners.isEmpty()) {
// Only reschedule, if at least one listener is ... listening
Location newLoc = locationSensor.getLastLocation();
listeners.forEach((LocationListener listener) -> listener
.onLocationChanged(host, newLoc));
lastLocation = newLoc;
Event.scheduleWithDelay(interval, this, null, eventTypeSeq);
}
}
}