So i'm trying to make a clicker, and everything compiles fine, but whenever I click my button i get a java.lang.NullPointerException.
Can anybody see what might be the problem? Btw I also copy pasted from projects I did a while back so that might be the problem.
Button code -
Counter code -
Thank you to anyone who helps in advance.
import greenfoot.*;
/**
* Write a description of class Button here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Button extends Actor
{
private Counter scoreCounter;
GreenfootSound music = new GreenfootSound("horn.wav");
Space space = (Space) getWorld();
/**
* 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()
{
Click();
}
public Button()
{
GreenfootImage image = getImage();
image.scale(image.getWidth() / 2, image.getHeight() / 2);
setImage(image);
}
public void Click()
{
if (Greenfoot.mouseClicked(this))
{
scoreCounter.add(1);
}
}
}
import greenfoot.*;
import java.awt.Color;
/**
* Write a description of class Counter here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Counter extends Actor
{
private static final Color transparent = new Color(0,0,0,0);
private GreenfootImage background;
private int value;
private int target;
private String prefix;
private Item item;
public Counter()
{
this(new String());
}
/**
* Create a new counter, initialised to 0.
*/
public Counter(String prefix)
{
background = getImage(); // get image from class
value = 0;
target = 0;
this.prefix = prefix;
updateImage();
}
/**
* Animate the display to count up (or down) to the current target value.
*/
public void act()
{
if (value < target) {
value++;
updateImage();
}
else if (value > target) {
value--;
updateImage();
}
}
/**
* Add a new score to the current counter value. This will animate
* the counter over consecutive frames until it reaches the new value.
*/
public void add(int score)
{
target += score;
}
/**
* Return the current counter value.
*/
public int getValue()
{
return target;
}
/**
* Set a new counter value. This will not animate the counter.
*/
public void setValue(int newValue)
{
target = newValue;
value = newValue;
updateImage();
}
/**
* Sets a text prefix that should be displayed before
* the counter value (e.g. "Score: ").
*/
public void setPrefix(String prefix)
{
this.prefix = prefix;
updateImage();
}
/**
* Update the image on screen to show the current value.
*/
private void updateImage()
{
GreenfootImage image = new GreenfootImage(background);
GreenfootImage text = new GreenfootImage(prefix + value, 22, Color.BLACK, transparent);
if (text.getWidth() > image.getWidth() - 20)
{
image.scale(text.getWidth() + 20, image.getHeight());
}
image.drawImage(text, (image.getWidth()-text.getWidth())/2,
(image.getHeight()-text.getHeight())/2);
setImage(image);
}
public void pay(int amount)
{
if (amount >= target)
{
target -= amount;
item.ifAllowed();
}
}
}
