Channel ch;
boolean bover = false;
boolean locked = false;
int bdifx = 0; 
int bdify = 0;

void setup()
{
  size(200, 200);
  smooth();   
  noStroke();  
  ch = new Channel(100,100);
}

void draw()
{
  background(0);
  ch.display();
}

void mousePressed()
{
  if((mouseX >=(ch.x-30))&&(mouseX<=ch.x+30)&&(mouseY>=(ch.y-30))&&(mouseY<=ch.y+30))
  {
    locked = true;
    ch.glow();
    bdifx = mouseX-ch.x; 
    bdify = mouseY-ch.y;     
  }
  else
  {
    locked = false;
  }
  
}

void mouseDragged()
{
  if(locked)
    ch.move(mouseX-bdifx,mouseY-bdify);
}

void mouseReleased()
{
  locked = false;
  ch.removeGlow();
}

class ChannelCircle
{
  int x;
  int y;
  int r;
  color c;
  ChannelCircle(color colorcode, int radius, int x_coordinate, int y_coordinate)
  {
    x = x_coordinate;
    y = y_coordinate;
    r = radius;
    c = colorcode;
  }
  
  void display()
  {    
    fill(c);
    ellipse(x,y,r,r);
  }

  void move(int x_coordinate, int y_coordinate)
  {
    x = x_coordinate;
    y = y_coordinate;
  }  
}

class Channel
{
  int x;
  int y;
  ChannelCircle c1;
  ChannelCircle c2;
  ChannelCircle c3;
  ChannelCircle c4;
  int r1;
  int r2;
  int r3;
  int r4;
  
  Channel(int xc,int yc)
  {
    x = xc;
    y = yc;
    r1 = 30; r2 = 40; r3 =50; r4 =60;
    c1 = new ChannelCircle(color(0,65,81), r1, xc,yc);
    c2 = new ChannelCircle(color(54,120,136), r2, xc,yc);
    c3 = new ChannelCircle(color(0,65,81), r3, xc,yc);
    c4 = new ChannelCircle(color(82,81,0), r4, xc,yc);
  }
  
  void display()
  {
    c4.display();
    c3.display();
    c2.display();
    c1.display();
  }
  
  void move(int xc, int yc)
  {
    x =xc; y = yc;
   c1.move(xc,yc);
   c2.move(xc,yc);
   c3.move(xc,yc);
   c4.move(xc,yc);
  }
  
  void glow()
  {
    c4.r = 60;
    c4.c = color(245,157,42);   
  }
  
  void removeGlow()
  {
    c4.r = 60;
    c4.c = color(82,81,0);
  }
}