Added factory class for producing mark arrows.

#story[1118]

src/main/java/seng302/visualiser/fxObjects/MarkArrowFactory.java

@@ -0,0 +1,56 @@
+package seng302.visualiser.fxObjects;
+
+import javafx.scene.Group;
+import javafx.scene.paint.Paint;
+import javafx.scene.shape.Line;
+import javafx.scene.shape.Polyline;
+
+/**
+ * Created by cir27 on 9/08/17.
+ */
+public class MarkArrowFactory {
+
+    public enum RoundingType {
+        PORT,
+        STARBOARD,
+    }
+
+    public static Group constructEntryArrow (RoundingType roundingSide, double angleOfEntry,
+        double angleOfExit, Paint colour) {
+        Group arrow = new Group();
+        return arrow;
+    }
+
+    public static Group constructExitArrow (RoundingType roundingSide, double angleOfEntry, Paint colour) {
+        Group arrow = new Group();
+        Line arrowBody;
+        Polyline arrowHead = constructArrowHead();
+        if (roundingSide == RoundingType.PORT) {
+            arrowBody = new Line(
+                -10, -10,
+                -10, -30
+            );
+            arrowHead.setLayoutX(-10);
+            arrowHead.setLayoutY(-10);
+        } else {
+            arrowBody = new Line(
+                10, -10,
+                10, -30
+            );
+            arrowHead.setLayoutX(10);
+            arrowHead.setLayoutY(-10);
+        }
+        arrowBody.setFill(colour);
+        arrowHead.setFill(colour);
+        arrow.getChildren().addAll(arrowBody, arrowHead);
+        return arrow;
+    }
+
+    private static Polyline constructArrowHead () {
+        return new Polyline(
+            -5, -5,
+            0, 0,
+            5, -5
+        );
+    }
+}

src/main/java/seng302/visualiser/fxObjects/Marker.java

@@ -1,19 +1,33 @@
 package seng302.visualiser.fxObjects;
 
+import javafx.application.Platform;
+import javafx.scene.Group;
 import javafx.scene.paint.Paint;
 import javafx.scene.shape.Circle;
 
 /**
  * Visual object for a mark.
  */
-public class Marker extends Circle {
+public class Marker extends Group {
+
+    Circle mark = new Circle();
+    Group enterArrow;
+    Group exitArrow;
 
     public Marker() {
-        super.setRadius(5);
+        mark.setRadius(5);
     }
 
     public Marker(Paint colour) {
         this();
-        super.setFill(colour);
+        mark.setFill(colour);
+    }
+
+    public void showEnterArrow () {
+        Platform.runLater(() -> this.getChildren().setAll(enterArrow));
+    }
+
+    public void showExitArrow () {
+        Platform.runLater(() -> this.getChildren().setAll(exitArrow));
     }
 }