Note: The QuadWindow.java code will be provided at the bottm. I just need help with creating a graph of the quadratic function using GPanel. Thanks.

Code Source:

QuadWindow.java

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class QuadWindow extends JFrame{

private JTextField CoA, CoB, CoC;

// roots are readonly fields so labels

private JLabel Root1, Root2, Complex;

private JLabel CoAx, CoBx, CoCx, Root1x, Root2x,Complexno;

private JButton calculateB, exitB;

private CalculateButtonHandler cbHandler;

private ExitButtonHandler ebHandler;

public QuadWindow(){

setTitle("Quadratic Fun"); //Title of the window

//Create the five labels

CoAx = new JLabel("A", SwingConstants.CENTER);

CoBx = new JLabel("B", SwingConstants.CENTER);

CoCx = new JLabel("C", SwingConstants.CENTER);

Root1x = new JLabel("Root1", SwingConstants.CENTER);

Root2x = new JLabel("Root2", SwingConstants.CENTER);

Complexno = new JLabel("Complex root", SwingConstants.CENTER);

//Creating 3 text fields

CoA = new JTextField(10);

CoB = new JTextField(10);

CoC = new JTextField(10);

//Creating 3 labels to show the result, initially it's empty

Root1 = new JLabel("", SwingConstants.RIGHT);

Root2 = new JLabel("", SwingConstants.RIGHT);

Complex = new JLabel("", SwingConstants.RIGHT);

//Create Calculate Button

calculateB = new JButton("Calculate");

cbHandler = new CalculateButtonHandler();

calculateB.addActionListener(cbHandler);

//Create Exit Button

exitB = new JButton("Exit");

ebHandler = new ExitButtonHandler();

exitB.addActionListener(ebHandler);

// we will use a GridLayout we have to display

// a

// b

// c

// root 1

// root 2

//complex no

// 2 buttons

// hence 7 rows 2 columns

Container pane = getContentPane();//Get the container

pane.setLayout(new GridLayout(7, 2));//Set the Layout

//Placing the components in the pane/window

pane.add(CoAx);

pane.add(CoA);

pane.add(CoBx);

pane.add(CoB);

pane.add(CoCx);

pane.add(CoC);

pane.add(Root1x);

pane.add(Root1);

pane.add(Root2x);

pane.add(Root2);

pane.add(Complexno);

pane.add(Complex);

pane.add(calculateB);

pane.add(exitB);

setSize(400,300);

setVisible(true);

setDefaultCloseOperation(EXIT_ON_CLOSE);

}

private class CalculateButtonHandler implements ActionListener//Creates a class on top of the interface

{

public void actionPerformed(ActionEvent e)

{

//Once user click on calculate after that user is not allowed to change the values hence disabling it.

CoA.setEditable(false);

CoB.setEditable(false);

CoC.setEditable(false);

//Storing the inputs into a variable

double a = Double.parseDouble(CoA.getText());

double b = Double.parseDouble(CoB.getText());

double c = Double.parseDouble(CoC.getText());

double root1,root2;

double determinant = b * b - 4 * a * c;

// condition for real and different roots

if(determinant > 0) {

root1 = (-b + Math.sqrt(determinant)) / (2 * a);

root2 = (-b - Math.sqrt(determinant)) / (2 * a);

Root1.setText("" + root1);

Root2.setText("" + root2);

}

// Condition for real and equal roots

else if(determinant == 0) {

root1 = root2 = -b / (2 * a);

Root1.setText("" + root1);

Root2.setText("" + root2);

}

// If roots are not real

else {

double realPart = -b / (2 *a);

double imaginaryPart = Math.sqrt(-determinant) / (2 * a);

String complex = String.format("%.2f+%.2fi and %.2f-%.2fi", realPart, imaginaryPart, realPart, imaginaryPart);

Complex.setText("" + complex);

}

}

}

private class ExitButtonHandler implements ActionListener//Creates a class on top of the interface

{

public void actionPerformed(ActionEvent e)

{

System.exit(0);

}

}

public static void main ( String[] args)

{

QuadWindow polynomial = new QuadWindow(); // Creating an object of QuadWindow to invoke the constrcutor

}

}

Sample Run:

Extend your QuadWindow, using the GPanel we did in class, to draw a picture of the quadratic function, with axes and tic marks. Just make a JPanel of some reasonable size in your window, turn it into a GPanel, and put the calls into the paint method of the GPanel. Oh,and you'll have to send in the a, b, and c, maybe using a new methods setQuadratic(a,b,c), so that your GPanel knows what quadratic to draw Sample graph (to be added to existing QuadWindow): Xmin -10.0 Xmax 10.0 Ymin -10.0 Ymax 10.0 A 2 B -14 C 24 Draw Graph Extend your QuadWindow, using the GPanel we did in class, to draw a picture of the quadratic function, with axes and tic marks. Just make a JPanel of some reasonable size in your window, turn it into a GPanel, and put the calls into the paint method of the GPanel. Oh,and you'll have to send in the a, b, and c, maybe using a new methods setQuadratic(a,b,c), so that your GPanel knows what quadratic to draw Sample graph (to be added to existing QuadWindow): Xmin -10.0 Xmax 10.0 Ymin -10.0 Ymax 10.0 A 2 B -14 C 24 Draw Graph