gistfile1.txt

Button myB1;
Button myB2;
Button myB3;
Button myB4;

void setup()
{
  size(400, 150);
  background(255);
  myB1 = new Button(50,50,50,50,color(255,0,0), "Button 1");
  myB2 = new Button(150,50,50,50,color(0,255,0), "Button 2");
  myB3 = new Button(250,50,50,50,color(0,0,255), "Button 3");
  myB4 = new Button(300,150, "twitter_icon.png");
//myB4 = new Button(300,150, loadImage("twitter_icon.png"));
}

void draw()
{
  myB1.drawButton();
  myB2.drawButton();
  myB3.drawButton();
  myB4.drawButton();
  
  myB1.isPositionWithinButton(mouseX, mouseY);
  myB2.isPositionWithinButton(mouseX, mouseY);
  myB3.isPositionWithinButton(mouseX, mouseY);
  myB4.isPositionWithinButton(mouseX, mouseY);
}
///////////////////////////////////////////////////////////////
class Button
{
  float _x;   //position x
  float _y;   //position y
  float _sX;  //sizeX (width?)
  float _sY;  //sizeY (height?)
  color _c;   //color
  String _t;  //text
  PImage _image = null; //see drawButton
  //PImage _image; //you don't have to do this because of: PImage _image = null;
  
  //this is the constructor, constructors doesn't have a type so they can't be voids
  Button(float x, float y, float sX, float sY, color c, String t)
  {
    _x = x;
    _y = y;
    _sX = sX;
    _sY = sY;
    _c = c;
    _t = t;
  }
  //
  Button(float x, float y, PImage image)
  {
    _x = x;
    _y = y;
    _image = loadImage(image);
    _t = image;
    _sX = _image.width;
    _sY = _image.height;
  }
  //
  void drawButton()
  {
    //you do this to avoid crashing the program if the image isn't there
    if (_image == null)
    {
      fill(_c); 
    //fill(_red,_green,_blue); instead of color _c;
      text(_t, _x, _y-10);
      rect(_x, _y, _sX, _sY);
    }
    else
    {
      image(_image, _x, _y);
    }
  }
  //
  boolean isPositionWithinButton(float x, float y)
  {
    if (x > _x && x < _x+_sX && y > _y && y < _y+_sY)
    {
      println(_t);
      return true;
    }
    else
      return false;
  }
  //
}