DigitalSensorEmitter.java

/*
 * This file is part of CBCJVM.
 * CBCJVM 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
 * (at your option) any later version.
 * 
 * CBCJVM 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 CBCJVM.  If not, see <http://www.gnu.org/licenses/>.
 */

package cbccore.sensors.digital;

import cbccore.sensors.IBooleanSensor;
import cbccore.events.Event;
import cbccore.events.EventType;
import cbccore.events.EventManager;

/**
 * An unintuitive but necessary class to interface buttons with the event system
 * Call DigitalSensorEmitter.get().start(); to begin listening for button
 * events. DigitalSensorEmitter.get().exit(); will stop listening for button
 * events. Connect Listeners that you make to the EventTypes available in this
 * class, and when a button is pressed/released, the handler will be called.
 * 
 * @author Braden McDorman, Benjamin Woodruff
 */
@SuppressWarnings("unchecked")
public class DigitalSensorEmitter extends Thread {
	
	private EventManager manager;
	
	private static final int minPort = 8;
	private static final int maxPort = 15;
	
	private IBooleanSensor[] sensors = new IBooleanSensor[maxPort-minPort];
	private Event[] sensorOnEvents = new Event[maxPort-minPort];
	private Event[] sensorOffEvents = new Event[maxPort-minPort];
	private EventType[] sensorOnEventTypes = new EventType[maxPort-minPort];
	private EventType[] sensorOffEventTypes = new EventType[maxPort-minPort];
	private boolean[] sensorStates = new boolean[maxPort-minPort];
	
	private boolean exit = false;
	
	private static DigitalSensorEmitter instance = null;

	public DigitalSensorEmitter(EventManager manager) {
		setDaemon(false);
		this.manager = manager;
	}

	public static DigitalSensorEmitter get() {
		if (instance == null)
			instance = new DigitalSensorEmitter(EventManager.get());
		return instance;
	}
	
	
	public EventType getTouchPressedType(int index) {
		index -= minPort;
		EventType type = sensorOnEventTypes[index];
		if(type != null) {
			if(!(sensors[index] instanceof Touch)) {
				throw new RuntimeException("EventType was already allocated to a different type of sensor.");
			}
			return sensorOnEventTypes[index];
		}
		sensorOnEventTypes[index] = manager.getUniqueEventType();
		sensorOnEvents[index] = new Event(sensorOnEventTypes[index], this);
		return sensorOnEventTypes[index];
	}
	
	public EventType getTouchReleasedType(int index) {
		index -= minPort;
		EventType type = sensorOffEventTypes[index];
		if(type != null) {
			if(!(sensors[index] instanceof Touch)) {
				throw new RuntimeException("EventType was already allocated to a different type of sensor.");
			}
			return sensorOffEventTypes[index];
		}
		sensorOffEventTypes[index] = manager.getUniqueEventType();
		sensorOffEvents[index] = new Event(sensorOffEventTypes[index], this);
		return sensorOffEventTypes[index];
	}
	
	
	
	public EventType getBeamPressedType(int index) {
		index -= minPort;
		EventType type = sensorOnEventTypes[index];
		if(type != null) {
			if(!(sensors[index] instanceof BreakBeam)) {
				throw new RuntimeException("EventType was already allocated to a different type of sensor.");
			}
			return sensorOnEventTypes[index];
		}
		sensorOnEventTypes[index] = manager.getUniqueEventType();
		sensorOnEvents[index] = new Event(sensorOnEventTypes[index], this);
		return sensorOnEventTypes[index];
	}
	
	public EventType getBeamReleasedType(int index) {
		index -= minPort;
		EventType type = sensorOffEventTypes[index];
		if(type != null) {
			if(!(sensors[index] instanceof BreakBeam)) {
				throw new RuntimeException("EventType was already allocated to a different type of sensor.");
			}
			return sensorOffEventTypes[index];
		}
		sensorOffEventTypes[index] = manager.getUniqueEventType();
		sensorOffEvents[index] = new Event(sensorOffEventTypes[index], this);
		return sensorOffEventTypes[index];
	}
	
	
	/**
	 * Don't call this function. Call start() instead.
	 */
	@Override
	public void run() {
		while (!exit) {
			for(int i = 0; i < sensors.length; ++i) {
				if(sensors[i] != null) {
					
					
					
					boolean newState = sensors[i].getValue();
					if (newState != sensorStates[i]) {
						if (newState) {
							sensorOnEvents[i].emit();
						} else {
							sensorOffEvents[i].emit();
						}
						sensorStates[i] = newState;
					}
					
					
					
					
				}
			}
			Thread.yield();
			try { Thread.sleep(0l, 1); } catch (Exception e) {}
		}
		exit = false;
	}
	
	//dangerous
	public void exit() {
		exit = true;
	}
}