Arrows work. mark arrow thinner. refactored marker class.

#fix

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

@@ -0,0 +1,38 @@
+package seng302.visualiser.fxObjects;
+
+import java.util.ArrayList;
+import java.util.List;
+import javafx.scene.Group;
+import seng302.visualiser.fxObjects.MarkArrowFactory.RoundingSide;
+
+/**
+ * Created by cir27 on 28/09/17.
+ */
+public abstract class Marker extends Group{
+
+    protected List<Group> enterArrows = new ArrayList<>();
+    protected List<Group> exitArrows = new ArrayList<>();
+    protected int enterArrowIndex = 0;
+    protected int exitArrowIndex = 0;
+
+    public abstract void addArrows(RoundingSide roundingSide, double entryAngle, double exitAngle);
+    /**
+     * Shows the next EnterArrow. Does nothing if there are no more enter arrows. Other arrows become hidden.
+     */
+    public void showNextEnterArrow() {
+        showArrow(enterArrows, enterArrowIndex);
+        enterArrowIndex++;
+    }
+
+    /**
+     * Shows the next ExitArrow. Does nothing if there are no more enter arrows. Other arrows become hidden.
+     */
+    public void showNextExitArrow() {
+        showArrow(exitArrows, exitArrowIndex);
+        exitArrowIndex++;
+    }
+
+    protected abstract void showArrow(List<Group> arrowList, int arrowListIndex);
+
+    public abstract void hideAllArrows();
+}