Java Programming question

[STARTER CODE BELOW]

import javax.swing.*;

import java.awt.*;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.image.BufferedImage;

/*** I DON'T RECOMMEND TO CHANGE THE BELOW CODE (EVEN THOUGH YOU CAN) ***/

public class Main {

public static void main(String[] args) {

showWindow();

}

// DON'T CHANGE THE METHOD SIGNATURE OF showWindow()

public static MainWindow showWindow() {

return new MainWindow();

}

}

/*** I DON'T RECOMMEND TO CHANGE THE ABOVE CODE (EVEN THOUGH YOU CAN) ***/

class MainWindow extends JFrame {

public MainWindow() {

super("Paint Tool");

setContentPane(createContentPane());

setSize(600, 400);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setVisible(true);

}

private JPanel createContentPane() {

CanvasPanel canvas = new CanvasPanel();

canvas.addMouseListener(new MouseAdapter() {

int startX;

int startY;

@Override

public void mousePressed(MouseEvent e) {

/********************************/

/* You need to write code here. */

/********************************/

}

@Override

public void mouseReleased(MouseEvent e) {

/********************************/

/* You need to write code here. */

/********************************/

}

});

JPanel contentPane = new JPanel(new BorderLayout());

contentPane.add(canvas, BorderLayout.CENTER);

return contentPane;

}

}

class CanvasPanel extends JPanel {

private final BufferedImage image;

public CanvasPanel() {

setName("canvas");

image = new BufferedImage(320, 240, BufferedImage.TYPE_INT_RGB);

Graphics2D g = image.createGraphics();

g.setColor(Color.WHITE);

g.fillRect(0, 0, image.getWidth(), image.getHeight());

g.dispose();

}

/**

* Draws a rectangle filled with black color between (x1, y1) and (x2, y2).

* Note that you cannot expect x1

* (x1, y1) (x2, y2)

* x1

*/

public void drawRectangle(int x1, int y1, int x2, int y2) {

/********************************/

/* You need to write code here. */

/********************************/

repaint();

}

@Override

public void paint(Graphics g) {

g.drawImage(image, 0, 0, this);

}

}

eate a program that shows a window meeting the following requirements. - The title of the window ( ) is - The following component at least is shown immediately after the window is shown. There is a panel (_ ) with the name meeting the following requirements. - A white rectangle with a width of 320 and a height of 240 is displayed in the upper left corner of the panel. The area where the white rectangle was first displayed is called drawing area. - When the left button of the mouse is pressed in the drawing area, the mouse pointer is moved, and the left button is released, a rectangle is drawn according to the following specification. - Let (x1,y1) and (x2,y2) be the location of the mouse pointer where the left button is pressed and released, respectively. - Let min(a,b) and max(a,b) be functions which return a smaller and larger parameter (i.e., a or b ), respectively. - Consider a rectangle whose upper left coordinate is (min(x1,x2),min(y1,y2)) and the lower right coordinate is (max(x1,x2),max(y1,y2)). - Fill the rectangle (including the upper left, but excluding lower right) with black. Note fillRect( ) is a useful method. - c.f. https://docs.oracle.com/javase/8/docs/api/java/awt/Graphics.html\#fillRect-int-int-int-int- - For example, if the upper left and lower right corners are (1,1) and (2,2), respectively, only one dot at (1,1) must be filled in black. - Don't need to render a rectangle until the left button is released