color currentcolor;
  
  CircleButton circle1, circle2, circle3;
  RectButton rect1, rect2;
  
  boolean locked = false;
  
  void setup()
  {
    size(200, 200);
    smooth();
  
    color baseColor = color(102);
    currentcolor = baseColor;
  
    // Define and create circle button
    color buttoncolor = color(204);
    color highlight = color(153);
    ellipseMode(CENTER);
    circle1 = new CircleButton(30, 100, 100, buttoncolor, highlight);
  
    // Define and create circle button
    buttoncolor = color(204);
    highlight = color(153); 
    circle2 = new CircleButton(130, 110, 24, buttoncolor, highlight);
  
    // Define and create circle button
    buttoncolor = color(153);
    highlight = color(102); 
    circle3 = new CircleButton(130, 140, 24, buttoncolor, highlight);
  
    // Define and create rectangle button
    buttoncolor = color(102);
    highlight = color(51); 
    rect1 = new RectButton(150, 20, 100, buttoncolor, highlight);
  
    // Define and create rectangle button
    buttoncolor = color(51);
    highlight = color(0); 
    rect2 = new RectButton(90, 20, 50, buttoncolor, highlight);
  }
  
  void draw()
  {
    background(currentcolor);
    stroke(255);
    update(mouseX, mouseY);
    circle1.display();
    circle2.display();
    circle3.display();
    rect1.display();
    rect2.display();
  }
  
  void update(int x, int y)
  {
    if(locked == false) {
      circle1.update();
      circle2.update();
      circle3.update();
      rect1.update();
      rect2.update();
    } 
    else {
      locked = false;
    }
  
    if(mousePressed) {
      if(circle1.pressed()) {
        currentcolor = circle1.basecolor;
      } 
      else if(circle2.pressed()) {
        currentcolor = circle2.basecolor;
      } 
      else if(circle3.pressed()) {
        currentcolor = circle3.basecolor;
      } 
      else if(rect1.pressed()) {
        currentcolor = rect1.basecolor;
      } 
      else if(rect2.pressed()) {
        currentcolor = rect2.basecolor;
      }
    }
  }
  
  class Button
  {
    int x, y;
    int size;
    color basecolor, highlightcolor;
    color currentcolor;
    boolean over = false;
    boolean pressed = false;   
  
    void update() 
    {
      if(over()) {
        currentcolor = highlightcolor;
      } 
      else {
        currentcolor = basecolor;
      }
    }
  
    boolean pressed() 
    {
      if(over) {
        locked = true;
        return true;
      } 
      else {
        locked = false;
        return false;
      }    
    }
  
    boolean over() 
    { 
      return true; 
    }
  
    boolean overRect(int x, int y, int width, int height) 
    {
      if (mouseX >= x && mouseX <= x+width && 
        mouseY >= y && mouseY <= y+height) {
        return true;
      } 
      else {
        return false;
      }
    }
  
    boolean overCircle(int x, int y, int diameter) 
    {
      float disX = x - mouseX;
      float disY = y - mouseY;
      if(sqrt(sq(disX) + sq(disY)) < diameter/2 ) {
        return true;
      } 
      else {
        return false;
      }
    }
  
  }
  
  class CircleButton extends Button
  { 
    CircleButton(int ix, int iy, int isize, color icolor, color ihighlight) 
    {
      x = ix;
      y = iy;
      size = isize;
      basecolor = icolor;
      highlightcolor = ihighlight;
      currentcolor = basecolor;
    }
  
    boolean over() 
    {
      if( overCircle(x, y, size) ) {
        over = true;
        return true;
      } 
      else {
        over = false;
        return false;
      }
    }
  
    void display() 
    {
      stroke(255);
      fill(currentcolor);
      ellipse(x, y, size, size);
    }
  }
  
  class RectButton extends Button
  {
    RectButton(int ix, int iy, int isize, color icolor, color ihighlight) 
    {
      x = ix;
      y = iy;
      size = isize;
      basecolor = icolor;
      highlightcolor = ihighlight;
      currentcolor = basecolor;
    }
  
    boolean over() 
    {
      if( overRect(x, y, size, size) ) {
        over = true;
        return true;
      } 
      else {
        over = false;
        return false;
      }
    }
  
    void display() 
    {
      stroke(255);
      fill(currentcolor);
      rect(x, y, size, size);
    }
  }