small typo fix in JavaDoc

GameProject/src/controller/MineController.java

@@ -4,7 +4,14 @@ import gameobjects.GameObject;
 
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.LogManager;
-
+/**
+ * Stops GameObject movement at bottom of level and let it 'fly' in x-direction towards ego object.
+ * If the object flies outside of the level (by x-coordinate) it is removed.
+ * 
+ * The behavior looks like a sinking sea mine, which stays at a certain depth and moves left/right to catch the player.
+ * 
+ *
+ */
 public class MineController extends ObjectController {
   int rad = 3;
 
@@ -17,13 +24,19 @@ public class MineController extends ObjectController {
     this.lineSpeed = lineSpeed;
   }
 
+  /**
+   * Fetches ego object by name 'ego' from current level and determines it's x-position.
+   * The controlled GameObject will move towards this position (in x-direction only).
+   * y-direction speed is reduced to zero, if the objects reached lower bound of level (high y-values).
+   * Only deletes the object if it flies out of visible game area.
+   */
   @Override
   public void updateObject() {
 
     if (gameObject.getY() >= this.getPlayground().getSizeY() - 10) {
       this.gameObject.setVY(0);
       if (xSpeed == 0.) {
-        GameObject ego = getPlayground().getObject("ego");
+        GameObject ego = this.getPlayground().getObject("ego");
         double egoXPos = ego.getX();
         if (egoXPos > this.gameObject.getX()) {
           xSpeed = 50;
@@ -38,9 +51,9 @@ public class MineController extends ObjectController {
     }
     if (this.gameObject.getX() < 0 || (this.gameObject.getX() > this.getPlayground().getSizeX())) {
       logger.debug("deleting" + this.gameObject.getId());
-      getPlayground().deleteObject(this.gameObject.getId());
+      this.getPlayground().deleteObject(this.gameObject.getId());
     }
 
-    applySpeedVector();
+    this.applySpeedVector();
   }
 }