import java.awt.Color;
import java.awt.event.*;
import javax.swing.*;

public class MoveImagesAlongEllipticalPath implements ActionListener
{
	private JFrame frame;
	private int frameWidth = 400, frameHeight = 300, numImages = 28;
	private ImageIcon image = new ImageIcon(getClass().getResource("data_files/apple.png"));
	private int imageWidth = image.getImage().getWidth(null);
	private int imageHeight = image.getImage().getHeight(null);
	private JLabel[] images = new JLabel[numImages];
	private int interval = 20, radiusX = 150, radiusY = 50, xPos = 0, yPos = 0, offset = 0;
	private double angle = 0;

	public static void main(String[] args)
	{
		new MoveImagesAlongEllipticalPath();
	}

	public MoveImagesAlongEllipticalPath()
	{
		// Create and set up a JFrame
		frame = new JFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setSize(frameWidth, frameHeight);
		frame.setTitle("Move Images in Elliptical Fashion");
		frame.setLocationRelativeTo(null);
		frame.setResizable(false);

		// Create an array of 'numImages' Images on JLabels and add to the JFrame
		for (int i = 0; i < numImages; i++)
		{
			images[i] = new JLabel(image);
			images[i].setSize(imageWidth, imageHeight);
			images[i].setLocation(-imageWidth, -imageHeight); // Start images off screen
			frame.add(images[i]);
		}

		images[numImages - 1].setVisible(false); // Hide a single wayward image
		frame.getContentPane().setBackground(Color.BLACK);
		frame.setVisible(true);

		// This timer will call the 'actionPerformed' method below when it fires
		Timer timer = new Timer(interval, this); // 'interval' is in milliseconds
		timer.start();
	}

	@Override
	public void actionPerformed(ActionEvent event)
	{
		// Using 'offset' ensures that the images do not overlap
		offset = ++offset % numImages;

		for (int i = 0; i < numImages; i++)
		{
			// Appropriately space and position each image along an elliptical
			// path; if 'radiusX' and 'radiusY' are the same, a circle is formed
			angle = i * (Math.PI / 12) + offset;
			xPos = (int) ((Math.cos(angle) * (radiusX)) + (frameWidth / 2 - 8));
			yPos = (int) ((Math.sin(angle) * (radiusY)) + (frameHeight / 2 - 20));
			images[i].setLocation(xPos, yPos);
		}
	}
}