public class Button extends Actor
{
    // Variables that are active for the entire Button class
    private static int songPlaying = 0; // The number (1, 2, ...) of the song playing, or 0 if no song is playing
    private static boolean isPaused= true;
    private static GreenfootSound gfs;         // The song to play 

    // Instance variables that are active for each instance of a Button
    private String image;               // This button's image
    private String song;                // This button's song name, or blank if the button is not a song
    private int buttonType;             // 1, 2, 3, ... for a song button, -1 for play/pause, -2 for stop
    
    private boolean isMouseClicked;     // True if the mouse was clicked on this instance
    private GreenfootImage image1;
    private GreenfootImage image2;
    
    private String sound;
    /**
     * Button constructor called when a new instance of a Button is created.
     */
    
    public Button(String imageName, String songName, int typeOfButton)
    {
        image = imageName;
        setImage(image);
        song = songName;
        
        buttonType = typeOfButton;
        image1 = new GreenfootImage("ButtonPlaySmall.png");
        image2 = new GreenfootImage("ButtonPauseSmall.png");
        
        sound=songName;
        gfs = new GreenfootSound(sound);
    }
    
    /**
     * Act - do whatever the Button wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        isMouseClicked = Greenfoot.mouseClicked(this);
        checkSongPlaying();
    }   
    
    /**
     * checkSongPlaying - if a song is playing, see if we stop it. If a song is not playing, see if we start it
     */
    
    private void checkSongPlaying()
    {
      if (isMouseClicked)
      {
            getWorld().showText("Button type: " + buttonType + ", song name: '" + song + "'", 250, 320);
      }
         
      if (isMouseClicked && buttonType < 0)
      {
            if (songPlaying == 0) //no song is playing
            {
                getWorld().showText("Hey! There's nothing playing!", 250, 300);
            }
            else //song is playing
            {
                getWorld().showText("Pausing song " + songPlaying, 100, 380);
                gfs.pause();
                if (getImage() == image1) 
                    {
                     setImage(image2);
                    }
                else
                    {
                     setImage(image1);
                    }
                    songPlaying = 0;
                
               
            }
            if (isPaused)
                { 
                    gfs.play();
                }
      }