Static fields in a class

kfrajer

Is it possible to work with static fields in my own class in Processing? How to?
Here is an example of what I want to do:

Auto a;

void setup(){
  size(400,400);
  Auto.ctr=0;
  a=new Auto();
}

void draw(){
  a.draw();
}

class Auto{

  static int ctr;
  Auto(){ctr++;}

  void draw(){text("Driving",width/2,height/2);}

}

However, I get an error: The field ctr cannot be declared static in an non-static inner type, unless initialized with a constant expression.

So, yes... If I do instead private static int ctr; then the error goes away but the functionality is lost. Is there a way to do this with a non-constant field at all?

Kf

jeremydouglass

but the functionality is lost.

Why? you can't write a getter for it? never mind -- I see now what you were trying to do in setup. See GoToLoop below.

GoToLoop

// forum.Processing.org/two/discussion/20578/
// static-fields-in-a-class#Item_2

// GoToLoop (2017-Jan-31)

Auto auto;

void setup() {
  size(300, 300);
  noLoop();

  textAlign(CENTER, CENTER);
  textSize(Auto.SIZE);
  fill(#FFFF00);

  Auto.ctr = 10;
  auto = new Auto();

  println(auto); // 11
}

void draw() {
  background(0);
  auto.display();
}

static abstract class Counter {
  static int ctr;

  @ Override String toString() {
    return str(ctr);
  }
}

class Auto extends Counter {
  static final int SIZE = 40;

  Auto() {
    ++ctr;
  }

  void display() {
    text("Driving", width>>1, height>>1);
  }
}

kfrajer

=D> Great, thxs. That will do for me.

Kf