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arkod86
arkod86 wrote ...

2017/11/5

Struggling to get Greenfoot.mouseClicked() to work

arkod86 arkod86

2017/11/5

#
I have a variable named value under the Canvas class. I've created an Object named myCanvas that acts as an energy bar. I want to increment my energy value whenever my Pet class gets clicked. Any help would be appreciated. Let me know if you need more code 
public void act() 
    {
        
        if(Greenfoot.mouseClicked(Food.class))
        {
            
            MyWorld realWorld = (MyWorld) getWorld();
            realWorld.myCanvas.value=realWorld.myCanvas.value+5;
        }
        
        idle();
    }
GreenfootImage img = new GreenfootImage(142,27);
    int value = 0;

    int col = 1; //col =1=green, col=2=blue
    
    public Canvas()
    {
        img.setColor(Color.WHITE);
        img.drawRect (0, 0, 141, 26);
        img.drawString("NRG:" +value/81*100,1,18);        
        img.setColor(Color.BLUE);
        img.fillRect(60,1,value,25);
        setImage(img);
    }

    public void act() 
    {
       
        updateBar();
    }    
    
    
    public void updateBar()
    {
        img.clear();
        img.setColor(Color.WHITE);
        img.drawRect (0, 0, 141, 26);
        img.drawString("NRG:"+value/81*100,1,18);
        img.setColor(Color.BLUE);        
        img.fillRect(60,1,value,25);
        setImage(img);
    }
public class MyWorld extends World
{

    /**
     * Constructor for objects of class MyWorld.
     * 
     */
    Muffin myMuffin = new Muffin();
    Canvas myCanvas = new Canvas();
    Canvas myECanvas = new Canvas();
    HealthBar myBar = new HealthBar();
    Food myFood = new Food();
    
    
    public MyWorld()
    {    
        // Create a new world with 600x400 cells with a cell size of 1x1 pixels.
        super(680, 425, 1); 
        addObject (myBar, 100, 15);
        addObject(myCanvas, 75, 80);
        addObject(myECanvas, 75, 50);
        addObject(myFood, 600, 350);
        
    }
    
}
danpost danpost

2017/11/5

#
Where is the first code block given (the 'act' method with the mouse click checking) located? Reason for asking is you said to add energy when Pet class is clicked; but the clicks are checked on Food class -- confusing. In Canvas class you could just have the following for the constructor: 
public Canvas()
{
    updateBar();
}
However, line 28 (which was also line 10), looks quite suspicious. Dividing by 81 before multiplying by 100 will lose accuracy. You might have to click 19 times (at 5 nrg points a click) before any value shows on the bar. Perform the multiplication first and the division last unless you are wanting to round to increments of 81.
arkod86 arkod86

2017/11/5

#
Right, the check is done on the Food class as I want to use it as a button to press to increase the value on the Pet. There was a mistake in my original question. Whenever the Food class is clicked increment energy of the Pet. The Act method is located on the Pet class. I think I saw my error. The check should be done on the Food class? Then my next error arrives how do I increment a value on one actor by accessing the World. I had a lesson on this but it was poorly explained. Code within food class: 
public void act() 
    {
        
        MyWorld realWorld = (MyWorld) getWorld();
        if(Greenfoot.mouseClicked(this))
        {
            realWorld.Pet.energy = realWorld.Pet.energy+5;
        }
    }
arkod86 arkod86

2017/11/5

#
What do I need to put in my code to access and change variables from another actor?
danpost danpost

2017/11/5

#
arkod86 wrote...
The check should be done on the Food class?
Actually, and I fell victim to this above (after seeing your code and not realizing the problem), the check is done on a specific object -- not a class at all. However, with the following, your check could be done anywhere: 
Object clicked = null;
if (Greenfoot.mouseClicked(null) && (clicked = Greenfoot.getMouseInfo().getActor()) != null && clicked instanceof Food)
Anywhere, provided the check is repeatedly performed (like from within an act method). The check will be 'true' any time any Food actor is clicked on.
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