I am starting to experiment with object-oriented programming within the Processing environment and have made some headway, albeit with much stumbling. At this point, however, I am stuck on this particular problem:

I want to initialize a class with a number of parameters that apply to all members of the class, but not to any particular instance. From what I have read, I understand that this can be done with a static method within the class definition, and this method can be invoked something like this: Class.init(params);

Here's the source code of a test example:

Circle myCircle;
float ranColor;

void setup(){
 size(300,300);
 background(255);
 framerate(10);
 fill(0);
 noStroke();
 ellipseMode(CENTER);
 myCircle = new Circle();
 Circle.init(width/2, height/2, width/2);
}
 
void draw(){
 ranColor=random(100);
 myCircle.update(ranColor);
}

public class Circle{

 float xPos;
 float yPos;
 float radius;
 float col;

 public static void init(float x, float y, float r){
   xPos   = x;
   yPos   = y;
   radius = r;
 }
 
 Circle(){
 }
 
 public void update(float c){
   col = c;
   fill(col);
   ellipse(xPos, yPos, radius, radius);
   redraw();
 }
}

The problem is, however, that when I run the sketch, I get the following error:

...Semantic Error: The static method "init" is invalid, because it is enclosed in an inner class, "Circle"...

I've tried for a few days to figure this out, but have been unsuccessful. Could someone please show me the way?

Thanks,

~BB~

As I read your original problem, I see this as a solution:
Code:

int var1 = 200;
String name = "John";
Hello goodMorning;
Hello goodBye;

void setup() {
  goodMorning = new Hello("Good morning");
  println(goodMorning.sayHello());
  goodBye = new Hello("Good bye");
  println(goodBye.sayHello());
}

void draw() {

}

class Hello {
  String internalName = name;
  String internalMessage;
  int size = var1;
  
  Hello(String message) {
    internalMessage = message;
  }
  
  String sayHello() {
    return internalMessage + " " + internalName + "!";
  }
} 

When you run this example (P0090) you get the result: Quote:

I set up a variable called String name = "John"; outside the class definition, and then used it inside the class definition, so that all objects of Hello would have the name John - I think this acheives your original goal. Both Hello objects goodMorning and goodBye both reference to "John".

So classes in Processing apps cannot have static methods? I'm guessing there was some support for this at one time since Dan Shiffman's Vector3D class on his Nature of Code website has a bunch of static methods. What happened?

I just got back to this after a processing hiatus this summer and this was indeed correct. I just changed Vector3D.pde to Vector3D.java and everything compiled nicely. Thanks!