This is the actual question, only do the part on 4 where you have to come up with something fancy other than square or circle. And you have to use the disply.java file that i am attaching 1. Create a class named PointTracer. 2. Create a Display object in the main method. 3. Call the drawNextPoint method with a coordinate of (200, 200) and run your program. A point should be drawn at the center of the screen. 4. Now that youve started your program, change it to draw the following in succession.  Box  Make the display window draw a point that moves around the screen to create a square. This means that you will have to modify the indices of the point to move right, then down, then left, and then up. You will need to use several loops for this.  Circle on Circle  Trace a point on the circumference of a circle that rotates around a point on the circumference of another circle. First, picture a point moving around the circumference of a circle. Use that point as the center of another circle (not necessarily the same size as the stationary circle) and draw the position of a point moving around that circle. See some mathematical explanations below.  Something Fancy - Come up with your own fancy version of a moving point. The idea should be more complex than the movement on the circle - Can you come up with some nifty pattern? Make sure that the loops for your box and circle on circle designs eventually terminate so the graders will be able to see all three parts of your program. The fancy third part can run forever if you like. Ive also provided you with two other methods to tell you how many pixels wide and how tall the display area is. Again using the Display variable above, we can query the display size and assign the values to variables, like so. int width = window . getWidth (); int height = window . getHeight (); window . drawNextPoint (25 , 40); Display window = new Display (50 , 5); This is the display.java file import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.*; import java.util.List; import javax.swing.*; import javax.swing.event.ChangeEvent; import javax.swing.event.ChangeListener; /** * The main Display class for the picture drawing assignment in 152. * * Displays points at user specified locations, with oldest points * fading away. */ public class Display { /** Default length of the trace */ private static final int DEFAULT_TRACE_LENGTH = 25; /** Default point size */ private static final int DEFAULT_POINT_SIZE = 5; /** Maximum delay for the speed slider */ private static final int MAX_DELAY = 500; /** * Special class for drawing dots on a display */ private class DisplayPanel extends JPanel { /** * Default constructor sets up default behavior */ public DisplayPanel() { setPreferredSize(new Dimension(400, 400)); setBackground(Color.BLACK); } public void paintComponent(Graphics g) { super.paintComponent(g); Iterator colorListIterator = colors.subList( colors.size() - points.size(), colors.size()).iterator(); int offset = -pointSize / 2; synchronized (points) { Iterator pointIterator = points.iterator(); while (pointIterator.hasNext()) { if (colorListIterator.hasNext()) { g.setColor(colorListIterator.next()); } Point p = pointIterator.next(); g.fillRect(p.x + offset, p.y + offset, pointSize, pointSize); } } } } /** * List of points */ private List points = null; /** * List of colors */ private List colors = null; /** * Current trace index */ private int maxTraceLength = DEFAULT_TRACE_LENGTH; /** * Delay to use for the update frequency */ private int updateDelay = MAX_DELAY / 4; /** * Starting color of the first point */ private Color pointColor = Color.RED; /** * Size of each point to draw */ private int pointSize = DEFAULT_POINT_SIZE; /** * Panel to draw points on */ private DisplayPanel drawPanel; /** * Construct display with default trace length and point size. */ public Display() { this(DEFAULT_TRACE_LENGTH, DEFAULT_POINT_SIZE); } /** * Main constructor for the display * @param traceLength The number of trace points to use * @param pointSize The size of each box point */ public Display(int traceLength, int pointSize) { setTraceLength(traceLength); JFrame mainFrame = new JFrame(); mainFrame.setSize(450, 450); mainFrame.setTitle("CS152 Point Tracer"); mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel control = new JPanel(); control.setPreferredSize(new Dimension(400, 50)); control.add(new JLabel("Speed:")); // Create the speed slider to control update frequency JSlider speedSlider = new JSlider(); speedSlider.setPreferredSize(new Dimension(75, 20)); speedSlider.setCursor(new Cursor(Cursor.HAND_CURSOR)); speedSlider.setMaximum(MAX_DELAY); speedSlider.setMinimum(0); speedSlider.setPaintTicks(false); speedSlider.setValue(updateDelay); speedSlider.addChangeListener(new ChangeListener() { public void stateChanged(ChangeEvent e) { JSlider s = (JSlider) e.getSource(); updateDelay = s.getValue(); } }); control.add(speedSlider); control.add(new JLabel("Length:")); JTextField lengthField = new JTextField(); lengthField.setPreferredSize(new Dimension(50, 20)); lengthField.setText("" + maxTraceLength); lengthField.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { JTextField jtf = (JTextField) e.getSource(); int length = maxTraceLength; try { length = Integer.parseInt(jtf.getText()); setTraceLength(length); } catch (NumberFormatException ex) { jtf.setText("" + length); } } }); control.add(lengthField); // Create a button that allows user to pick a new color to draw with final JButton colorButton = new JButton("Color"); colorButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) { Color chosenColor = JColorChooser.showDialog(colorButton, "Pick a color", pointColor); if (chosenColor != null) { pointColor = chosenColor; } generateColorSpectrum(); } }); control.add(colorButton); // Create the quit button so we can exit JButton quitButton = new JButton("Quit"); quitButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { System.exit(0); } }); control.add(quitButton); // Add the control panel to the main frame mainFrame.add(control, BorderLayout.SOUTH); // Create the JPanel that we will draw the points on drawPanel = new DisplayPanel(); mainFrame.add(drawPanel, BorderLayout.CENTER); if (pointSize < 1) { this.pointSize = 1; } else { this.pointSize = pointSize; } // Make sure the components are laid out properly and show the frame // at the center of the screen mainFrame.pack(); mainFrame.setLocationRelativeTo(null); mainFrame.setVisible(true); } /** * Draw the most recent point at position * @param x X position for new point. * @param y Y position for new point. */ public void drawNextPoint(int x, int y) { while (points.size() >= maxTraceLength) { points.remove(0); } points.add(new Point(x, y)); drawPanel.repaint(); // Sleep for delay milliseconds so that we can control update speed try { Thread.sleep(MAX_DELAY - updateDelay, 125); } catch (InterruptedException e) { // Got woken up, no need to worry } } /** * Return the height of the black part of the display * @return Panel height. */ public int getHeight() { return drawPanel.getHeight(); } /** * Return the width of the black part of the display * @return Panel width. */ public int getWidth() { return drawPanel.getWidth(); } /** * Return String representation of this Display object * @return String for the display. */ public String toString() { return "point display ( " + getWidth() + " by " + getHeight() + ")"; } /** * After updates of the color or size of spectrum, this method is called to * create the new set of colors to use when drawing */ private void generateColorSpectrum() { // Generate new color spectrum colors = Collections.synchronizedList(new LinkedList()); float alphaDiff = 1.0f / maxTraceLength; float red = pointColor.getRed() / 255f; float green = pointColor.getGreen() / 255f; float blue = pointColor.getBlue() / 255f; for (int i = maxTraceLength - 1; i >= 0; i--) { colors.add(new Color(red, green, blue, 1.0f - alphaDiff * i)); } } /** * Update the length of the point trace * @param length length of the trace, > 1 */ private void setTraceLength(int length) { // Set the new trace length maxTraceLength = length <= 1 ? 1 : length; generateColorSpectrum(); if (points == null) { points = Collections.synchronizedList(new LinkedList()); } else if (maxTraceLength < points.size()) { points = Collections.synchronizedList(points.subList(points .size() - maxTraceLength, points.size())); } } }

PLEASE EXPLAIN ME and you will have to use the disply.java file to write the code