programming
Graphical GUI user interface-based programming
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Windchill
Windchill There are several formulas for calculating the windchill temperature twc The one provided by U.S. National Weather Service and is applicable for a windspeed greater than four miles per hour
Where Variable t is the Fahrenheit temperature Variable v is the windspeed in miles per hour
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Console-based programming
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In use
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GUI-based programming
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Java support
JFrame Represents a titled, bordered window JLabel Represents a display area suitable for one or both of a singleline text or image. JTextField Represents an editable single-line text entry component JButton Represents a push button JTextArea Represents an editable multiline text entry component
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Instance variables
private JFrame window References the window containing the other components of the GUI
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Instance variables
private JTextArea legendArea References the text display for the multiline program legend
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Instance variables
private JLabel fahrTag References the label for the data entry area supplying the temperature
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Instance variables
private JTextField fahrText References the data area supplying the temperature
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Instance variables
private JLabel windTag References the label for the data entry area supplying the windspeed
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Instance variables
private JTextField windText References the data area supplying the windspeed
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Instance variables
private JLabel chillTag References the label for the data area giving the windchill
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Instance variables
private JTextField chillText References the data area giving the windchill
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Class constants
private static final String LEGEND = "This windchill calculator" + "is intended for velocities greater than 4 mph." Program legend text
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Class constants
private static final int WINDOW_WIDTH = 350 Initial width of the GUI
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Class constants
private static final int WINDOW_HEIGHT = 185 Initial height of the GUI
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Class constants
private static final int AREA_WIDTH = 40 Width of the program legend in characters
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Class constants
private static final int FIELD_WIDTH = 40 Number of characters per data entry area
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Class constants
private static final FlowLayout LAYOUT_STYLE = new FlowLayout() References manager that lays out GUI components in a topto-bottom, left-to-right manner
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Class constants
private static FlowLayout LAYOUT_STYLE = new FlowLayout() References manager that lays out GUI components in a topto-bottom, left-to-right manner
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Class constants
private static FlowLayout LAYOUT_STYLE = new FlowLayout() References manager that lays out GUI components in a topto-bottom, left-to-right manner
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Program Windchill.java
import javax.swing.*; import java.awt.*; import java.awt.event.*; public class Windchill implements ActionListener { // class constants // instance variables with initialization // Windchill(): default constructor // actionPerformed(): run button action event handler // main(): application entry point }
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Program Windchill.java class constants
private static final int WINDOW_WIDTH = 350; // pixels private static final int WINDOW_HEIGHT = 185; // pixels private static final int FIELD_WIDTH = 20; private static final int AREA_WIDTH = 40; // characters // characters
private static final FlowLayout LAYOUT_STYLE = new FlowLayout(); private static final String LEGEND = "This windchill " + "calculator is intended for velocities greater than 4 mph.";
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Program Windchill.java instance variables
// window for GUI private JFrame window = new JFrame("Windchill Calculator");
// legend private JTextArea legendArea = new JTextArea(LEGEND, 2, AREA_WIDTH);
// user entry area for temperature private JLabel fahrTag = new JLabel("Fahrenheit temperature"); private JTextField fahrText = new JTextField(FIELD_WIDTH);
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Program Windchill.java instance variables
// user entry area for windspeed private JLabel windTag = new JLabel(" Windspeed (mph)"); private JTextField windText = new JTextField(FIELD_WIDTH);
// entry area for windchill result private JLabel chillTag = new JLabel(" Windchill temperature");
private JTextField chillText = new JTextField(FIELD_WIDTH);
// run button private JButton runButton = new JButton("Run");
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Program Windchill.java constructor
public Windchill() { // configure GUI // register event listener // add components to container // display GUI }
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Program Windchill.java constructor
public Windchill() { // configure GUI window.setSize(WINDOW_WIDTH, WINDOW_HEIGHT); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
legendArea.setEditable(false); legendArea.setLineWrap(true); legendArea.setWrapStyleWord(true); legendArea.setBackground(window.getBackground()); chillText.setEditable(false);
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Bad chillText.setBackground(Color.WHITE);
line wrapping
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Program Windchill.java constructor
public Windchill() { // configure GUI window.setSize(WINDOW_WIDTH, WINDOW_HEIGHT); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
legendArea.setEditable(false); legendArea.setLineWrap(true); legendArea.setWrapStyleWord(true); legendArea.setBackground(window.getBackground()); chillText.setEditable(false); chillText.setBackground(Color.WHITE);
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Bad Line Wrapping
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Program Windchill.java constructor
public Windchill() { // configure GUI window.setSize(WINDOW_WIDTH, WINDOW_HEIGHT); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
legendArea.setEditable(false); legendArea.setLineWrap(true); legendArea.setWrapStyleWord(true); legendArea.setBackground(window.getBackground()); chillText.setEditable(false); chillText.setBackground(Color.WHITE);
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Program Windchill.java constructor
public Windchill() { // configure GUI ... // register event listener runButton.addActionListener(this);
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Run button action-event handling
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Program Windchill.java constructor
public Windchill() { // configure GUI ... // register event listener ... // add components to container Container c = window.getContentPane(); c.getContentPane().setLayout(LAYOUT_STYLE); c.getContentPane().add(legendArea); c.getContentPane().add(fahrTag); c.getContentPane().add(fahrText); c.getContentPane().add(windTag); c.getContentPane().add(windText); c.getContentPane().add(chillTag); c.getContentPane().add(chillText); c.getContentPane().add(runButton);
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Program Windchill.java constructor
public Windchill() { // configure GUI ... // register event listener ... // add components to container ... // make GUI visible window.setVisible(true);
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Laying out the GUI components
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Program Windchill.java action performer
public void actionPerformed(ActionEvent e) { // get user's responses // compute windchill // display windchill }
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Program Windchill.java action performer
public void actionPerformed(ActionEvent e) { // get user's responses String response1 = fahrText.getText(); double t = Double.parseDouble(response1); String response2 = windText.getText(); double v = Double.parseDouble(response2); // compute windchill // display windchill }
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Program Windchill.java action performer
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Program Windchill.java action performer
public void actionPerformed(ActionEvent e) { // get user's responses String response1 = fahrText.getText(); double t = Double.parseDouble(response1); String response2 = windText.getText(); double v = Double.parseDouble(response2); // compute windchill double windchillTemperature = 0.081 * (t - 91.4) * (3.71*Math.sqrt(v) + 5.81 - 0.25*v) + 91.4; int perceivedTemperature = (int) Math.round(windchillTemperature); // display windchill }
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Program Windchill.java action performer...