import java.awt.*;
import java.util.*;

public class things extends BufferedApplet
{
   final int N = 6;
   int w = 0, h = 0;
   Thing thing[] = new Thing[N];
   Random rand = new Random();
   Color offWhite = new Color(220,220,220);
   int n = -1;

   public void render(Graphics g) {

      if (w == 0) {
	 w = bounds().width;
	 h = bounds().height;

         for (int i = 0 ; i < N ; i++) {
	    thing[i] = new Thing();
	    thing[i].x = w/2 + (rand.nextInt() % (w/2));
	    thing[i].y = h/2 + (rand.nextInt() % (h/2));
	    thing[i].r = w/20;
         }
      }

      g.setColor(offWhite);
      g.fillRect(0,0,w,h);

      for (int i = 0 ; i < N ; i++) {

	 Thing T = thing[i];

	 // MAKE ME WIGGLE

         if (i != n) {
	    T.dx += (rand.nextInt() % 2);
	    T.dy += (rand.nextInt() % 2);
	    double v = Math.sqrt(T.dx*T.dx + T.dy*T.dy);
	    double maxV = 5;
	    if (v > maxV) {
	       T.dx *= maxV / v;
	       T.dy *= maxV / v;
	    }
	    T.x += T.dx;
	    T.y += T.dy;
         }

	 // DON'T LET THEM CRAWL ALL OVER EACH OTHER

	 for (int j = i+1 ; j < N ; j++) {
	    Thing S = thing[j];
	    double dx = T.x - S.x;
	    double dy = T.y - S.y;
	    double d = Math.sqrt(dx*dx + dy*dy);
	    if (d < T.r + S.r) {
	       double f = (T.r + S.r - d) / (T.r + S.r);
	       T.x += dx/2 * f;
	       T.y += dy/2 * f;
	       S.x -= dx/2 * f;
	       S.y -= dy/2 * f;
	    }
	 }

	 // DON'T LET ME ESCAPE

	 if (T.x >= w-T.r) { T.x = w-T.r; T.dx = -T.dx; }
	 if (T.y >= h-T.r) { T.y = h-T.r; T.dy = -T.dy; }
	 if (T.x <    T.r) { T.x =   T.r; T.dx = -T.dx; }
	 if (T.y <    T.r) { T.y =   T.r; T.dy = -T.dy; }

	 // DRAW ME

	 T.draw(g, i==n);
      }

      g.setColor(Color.black);
      g.drawRect(0,0,w-1,h-1);
   }

   public boolean mouseMove(Event e, int x, int y) {
      return true;
   }
   public boolean mouseDown(Event e, int x, int y) {
      return true;
   }
   public boolean mouseUp(Event e, int x, int y) {
      return true;
   }
   public boolean keyUp(Event e, int key) {
      switch (key) {
      case 'c':
	 for (int i = 0 ; i < N ; i++) {
	    thing[i].x = w/2;
	    thing[i].y = h/2;
	 }
	 break;
      }
      return true;
   }
   public boolean mouseDrag(Event e, int x, int y) {
      int i;
      for (i = N-1 ; i >= 0 ; i--)
	if (thing[i].hit(x,y)) {
	  thing[i].x = x;
	  thing[i].y = y;
	  break;
	}
      n = i;
      return true;
   }
}

class Thing
{
   double dx, dy, x, y, r = 10;

   void draw(Graphics g, boolean isSelected) {
      g.setColor(isSelected ? Color.pink : Color.white);
      g.fillOval((int)(x-r), (int)(y-r), (int)(2*r), (int)(2*r));
      g.setColor(Color.black);
      g.drawOval((int)(x-r), (int)(y-r), (int)(2*r), (int)(2*r));
   }

   boolean hit(double x, double y) {
      double dx = this.x - x;
      double dy = this.y - y;
      return dx*dx + dy*dy <= r*r;
   }
}