import javax.swing.*;
import java.util.Vector;
import java.awt.*;
public class jattack extends JFrame implements Runnable{
	
	public static Vector blockVector = new Vector();
	public Thread t;
	
	public void run(){ // Målar om skärmen var 10:e ms
		while (true){
			this.repaint();
			try { // Behövs
				t.sleep(5);
			}catch (InterruptedException e){}
			
			
		}
		
	}
	
	public jattack(){
		t=new Thread(this);
		t.start();
		
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setSize(400,200);
		this.setVisible(true);
	}
	
	public void paint(Graphics g){
	//	g.setColor(Color.white);
	//	g.fillRect(10,10,this.getWidth(),this.getHeight());
		for (int i=0;i<blockVector.size();i++){
			
			block b = ((block)blockVector.get(i));
			
			g.setColor(Color.white);
			g.drawRect(b.x,b.y,b.width,b.height);
			g.setColor(Color.black);
			b.calculateydirValue(this.getHeight());
			g.drawRect(b.x,b.y,b.width,b.height);
		}
	}
	
	public static void spawnBlocks() {
		int flagDir = -1;
		for (int i=0;i<10;i++){
			block b = new block();
			b.x += b.width*i; // Sätt kuben lite till höger
			
			if (flagDir == -1){ // Ge kuberna olika y-riktnings värden
				b.ydir=-1;
				flagDir = 1;
			}else{
				b.ydir = 1;
				flagDir = -1;
			}
			
			blockVector.add(b);
		}
	}
		
	public static void main(String[] args){
		spawnBlocks();
		jattack frame = new jattack();
	}	
}

class block{
	public int width = 20;
	public int height = 20;
	public int x = 100;
	public int y = 100;
	public int ydir = -1; // ner
	public void calculateydirValue(int max){
		if (y>max){
			ydir = -1;
		}
		if (y<0){
			ydir = 1;
		}	
		y+=ydir;
	}
		
	}