Complete Chapter 12 Lab Assignment 1212 and Chapter 13 Lab A

Complete Chapter 12 Lab Assignment 12.12 and Chapter 13 Lab Assignment 13.9. The Convert.java and Triangles.java classes are provided. You will need to complete the ConvertFrame.java and TrianglesPanel.java classes.

// Exercise 12.12 : Convert.java

//Temperature-conversion program

import javax.swing.JFrame;

public class Convert{

public static void main(String[] args) {

ConvertFrame convertFrame = new ConvertFrame();

convertFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

convertFrame.setSize(225, 90); // set frame size

convertFrame.setVisible(true); // display frame

}

} // end class Convert

// Exercise 12.12 : ConvertFrame.java

// Temperature-conversion program

import java.awt.BorderLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JTextField;

public class ConvertFrame extends JFrame {

private JLabel prompt;

// label to prompt user to enter Fahrenheit

// label to display temperature in Celsius   

// textfield to enter temperature

// constructor sets up GUI

public ConvertFrame() {   

//prompt to enter Fahrenheit temperature

// textfield for Fahrenheit

// register anonymous action listener

//get temperature, be user to parse value and convert to an integer

//calculate the celsius

//display celsius

//set border layouts

} // end ConvertFrame constructor

} // end class ConvertFrame

----------------------------------------------------------------------------------------------------------------------------------------------------

// Exercise 13.9 : Triangles.java

// Displays randomly generated triangles in different colors.

import javax.swing.JFrame;
public class Triangles{

public static void main(String args[]) {

// create frame for TrianglesJPanel

JFrame frame = new JFrame(\"Drawing Triangles\");

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

TrianglesJPanel trianglesJPanel = new TrianglesJPanel();  

frame.add(trianglesJPanel); // add trianglesJPanel to frame

frame.setSize(400, 400); // set frame size

frame.setVisible(true); // display frame

}

} // end class Triangles

// Exercise 13.9: TrianglesJPanel.java

// Displays randomly generated triangles in different colors.

import java.awt.Color;

import java.awt.geom.GeneralPath;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.util.Random;

import javax.swing.JPanel;

public class TrianglesJPanel extends JPanel{

// random-number generator   

// constructor sets background

public TrianglesJPanel() {

// set JPanel background color

}
// draw ten triangles

public void paintComponent(Graphics g) {

super.paintComponent(g);

// cast graphics object
// create a triangle from three random points

// create the object which will be the triangle   

// min distance between triangle and top/left

// size of area triangle appears in
// use method moveTo to start the triangle   
// draw a line to the second point   
// draw a line to the third point   
   // draw a line back to the initial point
// choose a random color
// color the interior of the triangle

}

}

} // end class TrianglesJPanel

Solution

13.9

package drawtriangleusingline2d;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.geom.Line2D;
import java.util.Random;

public class DrawTriangleUsingLine2D extends JApplet {
public void init() {
setBackground(Color.lightGray);
}
public void paint(Graphics g) {
Random r = new Random();
int x1 = r.nextInt((50-1)+1)+1;
int x2 = r.nextInt((150-1)+1)+1;
int y1 = r.nextInt((150-1)+1)+1;
int y2 = r.nextInt((150-1)+1)+1;
int y11 = r.nextInt((50-1)+1)+1;
int x22 = r.nextInt((50-1)+1)+1;
  
Graphics2D g2d = (Graphics2D) g;
g2d.setPaint(Color.red);
g2d.draw(new Line2D.Double(x1,y1,x2,y2 ));
g2d.draw(new Line2D.Double(50,y11,150,150 ));
g2d.draw(new Line2D.Double(50,50,x22,150 ));
}
public static void main(String s[]) {
JFrame frame = new JFrame(\"Show Triangle\");
JApplet applet = new DrawTriangleUsingLine2D();
frame.getContentPane().add(\"Center\", applet);
applet.init();
frame.setSize(500, 550);
frame.show();
}
}

12.12:

package fahrenheitgui;

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

public class FahrenheitGUI {
private int WIDTH = 300;
private int HEIGHT = 75;
private JFrame frame;
private JPanel panel;
private JLabel inputLabel, resultLabel;
private JTextField fahrenheit;

//-----------------------------------------------------------------
// Sets up the GUI.
//-----------------------------------------------------------------

public FahrenheitGUI() {
frame = new JFrame(\"Temperature Conversion\");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

inputLabel = new JLabel(\"Enter Fahrenheit temperature:\");
JLabel outputLabel = new JLabel(\"Temperature in Celsius: \");
resultLabel = new JLabel(\"---\");

fahrenheit = new JTextField(5);
fahrenheit.addActionListener(new TempListener());

panel = new JPanel();
panel.setPreferredSize(new Dimension(WIDTH, HEIGHT));
panel.setBackground(Color.yellow);
panel.add(inputLabel);
panel.add(fahrenheit);
panel.add(outputLabel);
panel.add(resultLabel);

frame.getContentPane().add(panel);

}

//-----------------------------------------------------------------
// Displays the primary application frame.
//-----------------------------------------------------------------

public void display() {
frame.pack();
frame.setVisible(true);

}

//*****************************************************************
// Represents an action listener for the temperature input field.
//*****************************************************************

private class TempListener implements ActionListener {
//--------------------------------------------------------------
// Performs the conversion when the enter key is pressed in
// the text field.
//--------------------------------------------------------------

public void actionPerformed(ActionEvent event) {
int fahrenheitTemp, celsiusTemp;

String text = fahrenheit.getText();

fahrenheitTemp = Integer.parseInt(text);
celsiusTemp = (fahrenheitTemp - 32) * 5 / 9;

resultLabel.setText(Integer.toString(celsiusTemp));
}
}
public static void main(String args[]){
FahrenheitGUI fh = new FahrenheitGUI();
fh.display();
  
}
}