////Kaido Heinsalu(IF-21) kodune ülesanne
////Ülesanne nägi ette, et ekraanile paigutatakse hiirega hulk ringe. Vajutades hiirega alla ühe ringi sees ning lastes nupu lahti teise ringi sees tõmmatakse nende ringide keskkohtade vahele joon 




import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
import java.util.LinkedList;



public class Lohistamine extends Applet implements MouseListener{
	int m, n, o, p;
	LinkedList RingidList = new LinkedList();


	public Lohistamine(){
			addMouseListener(this);			
	}


	class yldRing {
		int x;
		int y;
		public yldRing(int x_abi, int y_abi) {
			x = x_abi - 20;
			y = y_abi - 20;
		}
	}


	public void mousePressed(MouseEvent e) {
		m=0;
		n=0;
		boolean caught = false;
		if (RingidList.size() == 0){
			RingidList.add(new yldRing(e.getX(), e.getY()));
		}
		else {
			for (int i = 0; i < RingidList.size(); i++) {
				yldRing ringIsend = (yldRing)RingidList.get(i);
				if (kasRingil(ringIsend, e.getX(), e.getY())) {
					caught = true;
					m=ringIsend.x+20;
					n=ringIsend.y+20;
					break;
				}
			}
			if (!caught){
				RingidList.add(new yldRing(e.getX(), e.getY()));
			}
		}
		//repaint();
	}


	public void mouseReleased(MouseEvent e){
		o=0;
		p=0;
		for (int i = 0; i < RingidList.size(); i++) {
			yldRing ringIsend = (yldRing)RingidList.get(i);
			if (kasRingil(ringIsend, e.getX(), e.getY())) {
				o=ringIsend.x+20;
				p=ringIsend.y+20;
				repaint();				
				break;
			}
			
		}
	}


	public boolean kasRingil(yldRing ringIsend, int x, int y) {
		int xKaugus = x - ringIsend.x;
		int yKaugus = y - ringIsend.y;
		if (xKaugus <= 39 && xKaugus >= 0 && yKaugus <= 39 && yKaugus >= 0){
			return true;
		}
		else{
			return false;
		}
	}


	public void paint(Graphics g){
		for (int i = 0; i < RingidList.size(); i++) {
			yldRing ringIsend = (yldRing)RingidList.get(i);
			g.setColor(Color.blue);
			g.drawOval(ringIsend.x, ringIsend.y, 40, 40);
		}
		if (m!=0 && n!=0 && o!=0 && p!=0){
			g.setColor(Color.red);
			g.drawLine(m, n, o, p);
		}
		
	}


	public void mouseClicked(MouseEvent e){}
	public void mouseEntered(MouseEvent e){}
	public void mouseExited(MouseEvent e){}
	public void mouseMoved(MouseEvent e){}


	public static void main(String[] argumendid) {
		Frame f=new Frame();
		f.add(new Lohistamine());
		f.setSize(500, 500);
		f.setTitle("Lohista hiirega ühelt ringilt teisele, siis saab nalja!");
		f.setVisible(true);
		f.addWindowListener(new Aken());
	}

}


class Aken extends WindowAdapter {
	public void windowClosing(WindowEvent PALLIAKEN) {
		System.exit(0);
	}
}