Added interface IDrawingRollers

DrawingArtillery.java

@@ -2,7 +2,7 @@ import java.awt.*;
 
 public class DrawingArtillery {
     protected EntityArtillery artillery;
-    protected DrawingRollers drawingRollers;
+    protected IDrawingRollers drawingRollers;
     protected float _startPosX;
     protected float _startPosY;
     private Integer _pictureWidth = null;

DrawingRollers.java

@@ -1,6 +1,6 @@
 import java.awt.*;
 
-public class DrawingRollers {
+public class DrawingRollers implements IDrawingRollers {
     private RollersCount rollersCount;
     private Color color;
 

IDrawingRollers.java

@@ -0,0 +1,6 @@
+import java.awt.*;
+
+public interface IDrawingRollers {
+    void setRollersCount(int num);
+    void draw(Graphics2D g, int x, int y, int artilleryWidth, int artilleryHeight);
+}