package de.uulm.mi.gdg;

import processing.core.PApplet;

/**
 * The Equalizer class is the main controller for the Animation.
 *
 * @author Tobias Lahmann
 */
public class Equalizer extends PApplet {
    /**
     * The settings() method runs before the sketch has been set up, so other Processing functions cannot be used at
     * this point.
     */
    public void settings() {
        setSize(1240, 720);
    }

    /**
     * The setup method is called before displaying any objects. The Method calls commands in the Processing API.
     */
    public void setup() {

    }

    /**
     * Draw method is responsible for displaying all objects.
     */
    public void draw() {

    }

    /**
     * Main method to instantiate the PApplet.
     *
     * @param args Arguments passed to the PApplet.
     */
    public static void main(String[] args) {
        PApplet.main(new String[]{Equalizer.class.getName()});
    }
}

package de.uulm.mi.gdg;

import de.uulm.mi.gdg.objects.Circle;
import processing.core.PApplet;
import processing.core.PVector;

import java.util.ArrayList;

/**
 * The Equalizer class is the main controller for the Animation.
 *
 * @author Tobias Lahmann
 */
public class Equalizer extends PApplet {
    // A list of circles to hold the elements to display.
    private ArrayList<Circle> circles;

    /**
     * The settings() method runs before the sketch has been set up, so other Processing functions cannot be used at
     * this point.
     */
    public void settings() {
        setSize(1240, 720);
    }

    /**
     * The setup method is called before displaying any objects. The Method calls commands in the Processing API.
     */
    public void setup() {
        circles = new ArrayList<>();

        // Creates random circles to see what an animation could look like
        for (int i = 0; i < 10; i++) {
            float xPosition = random(this.width);
            float yPosition = random(this.height);
            PVector position = new PVector(xPosition, yPosition);
            float radius = random(10, 100);
            int color = color(0, 128, 128);
            Circle c = new Circle(position, radius, color);
            circles.add(c);
        }
    }

    /**
     * Draw method is responsible for displaying all objects.
     */
    public void draw() {
        // Display every circle available
        for (Circle c : circles) {
            stroke(c.color);
            ellipse(c.position.x, c.position.y, c.radius, c.radius);
        }
    }

    /**
     * Main method to instantiate the PApplet.
     *
     * @param args Arguments passed to the PApplet.
     */
    public static void main(String[] args) {
        PApplet.main(new String[]{Equalizer.class.getName()});
    }
}

Add 10 circles to the animation and display them