first commit

Box.java

@@ -0,0 +1,74 @@
+import java.awt.Graphics;
+import java.util.LinkedList;
+import java.util.Iterator;
+import javax.swing.*;
+
+public class Box extends JFrame
+{
+    private LinkedList<Drawable> drawable = new LinkedList<Drawable>(); 
+    private LinkedList<Collisionable> collisionable = new LinkedList<Collisionable>(); 
+    // Bullet 1, Tank 2, Plane 3, 
+
+    public Box(String title)
+    {
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setVisible(true);
+    }
+    
+    public void step()
+    {
+        // Move
+                
+        for(Iterator<Drawable> it = this.drawable.iterator(); it.hasNext();)
+        {
+            it.next().step();
+        }
+        
+        // Check collision
+        
+        for(int i = 0; i < this.collisionable.size(); i++)
+        {
+            Collisionable object = this.collisionable.get(i);
+            
+            for(Iterator<Collisionable> it = this.collisionable.iterator(); it.hasNext();)
+            {
+                Collisionable object2 = it.next();
+                
+                if(
+                    object != object2 &&
+                    object.getX() <= object2.getX() &&
+                    object.getX() + object.getWidth() >= object2.getX() &&
+                    object.getY() <= object2.getY() &&
+                    object.getY() + object.getHeight() >= object2.getY()
+                )
+                {
+                    object.collisionedWith(object2.collisionCheckSum());
+                    object2.collisionedWith(object.collisionCheckSum());
+                }
+            }
+            
+            if(object.isDead(this))
+            {
+                this.drawable.remove(i);
+                this.collisionable.remove(i);
+            }
+            
+        }
+    }
+       
+    public void paint(Graphics g)
+    {
+        super.paint(g);
+        
+        for(Iterator<Drawable> it = this.drawable.iterator(); it.hasNext();)
+        {
+            it.next().draw(g);
+        }        
+    }
+    
+    public void addObject(Drawable graphic)
+    {
+        this.drawable.add(graphic);
+        this.collisionable.add((Collisionable)graphic);
+    }
+}