Added function to generate events for race

- added generateEvents() for creating event into a priority queue
- added iterateEvents() to pull out events when time passing
- changed default velocity to 70 just for testing. Pls change it back after testing

#story[5] #implement

src/main/java/seng302/Boat.java

@@ -9,7 +9,7 @@ public class Boat
 {
 	// The name of the team, this is also the name of the boat
 	private String teamName = null;
-	private float velocity = 0;
+	private float velocity = 70; // please set this one to a reasonable num!!!!!, i set it just for testing ;)
 
 	public Boat(String teamName) {
 		this.teamName = teamName;

src/main/java/seng302/Race.java

@@ -1,21 +1,34 @@
 package seng302;
 
-import java.util.ArrayList;
-import java.util.Random;
-import java.util.Collections;
-import java.util.List;
+import java.util.*;
 
 
 public class Race {
 	private ArrayList<Boat> boats;
 	private ArrayList<Leg> legs;
+	private PriorityQueue<Event> events;
 	private int numberOfBoats = 0;
 	private long startTime = 0;
 	private int timeScale = 1;
 
 	public Race() {
-		boats = new ArrayList<Boat>();
-		legs = new ArrayList<Leg>();
+		this.boats = new ArrayList<Boat>();
+		this.legs = new ArrayList<Leg>();
+		// create a priority queue within custom Comparator to order events
+		this.events = new PriorityQueue<Event>(new Comparator<Event>() {
+			@Override
+			public int compare(Event o1, Event o2) {
+				Long time1 = o1.getTime();
+				Long time2 = o2.getTime();
+				// order event asc. by time. if tie appears, then order team
+				// name alphabetically.
+				if (time1 != time2) {
+					return time1.compareTo(time2);
+				} else {
+					return o1.getBoat().getTeamName().compareTo(o2.getBoat().getTeamName());
+				}
+			}
+		});
 	}
 
 	/*
@@ -107,6 +120,7 @@ public class Race {
 
 	/**
 	 * Gets legs array
+	 *
 	 * @return an array of legs
 	 */
 	public ArrayList<Leg> getLegs() {
@@ -114,7 +128,26 @@ public class Race {
 	}
 
 	/**
+	 * Temporary method used to generated all the events.
+	 */
+	private void generateEvents() {
+
+		//calculate the time for every boat passes each leg, and create an event
+		for (Boat boat : this.boats) {
+			long totalDistance = 0;
+			for (Leg leg : this.legs) {
+				totalDistance += leg.getDistance();
+				long time = (long) (1000 * totalDistance / (boat.getVelocity() * this.timeScale));
+				Event event = new Event(time, boat, leg);
+				events.add(event);
+			}
+		}
+	}
+
+	/**
+	 * Note: this function is useless so far
 	 * Calculates how far a boat has travelled in meter
+	 *
 	 * @param velocity the velocity of boat
 	 * @return a float number of distance the boat has been travelled
 	 */
@@ -124,15 +157,36 @@ public class Race {
 		return timeElapse * velocity;
 	}
 
+	/**
+	 * Micheal, here is a demo function shows you how to iterate all events
+	 */
+	public void iterateEvents() {
+		// iterates all events. ends when no event in events.
+		while (!events.isEmpty()) {
+			Event peekEvent = events.peek();
+			long currentTime = System.currentTimeMillis() - this.startTime;
+			if (currentTime > peekEvent.getTime()) {
+				// pull out the event
+				Event nextEvent = events.poll();
+				// I just simply print it out for testing
+				System.out.println(nextEvent.getTimeString() + ", " +
+						nextEvent.getBoat().getTeamName() + " passed " +
+						nextEvent.getLeg().getMarkerLabel());
+			}
+		}
+	}
+
 	/*
 		Start the race and print each marker with the order
 		in which the boats passed that marker
 	*/
 	public void startRace() {
 		// record start time.
+		generateEvents();
 		this.startTime = System.currentTimeMillis();
+		iterateEvents();
 
-		for (Leg leg : this.legs.toArray(new Leg[legs.size()])){
+		for (Leg leg : this.legs) {
 			Boat[] boats = this.getShuffledBoats();
 
 			System.out.println("--- " + leg.getMarkerLabel() + " ---");