Chapter 19 – Graphical User Interfaces. Chapter Goals To use layout managers to arrange user ‑ interface components in a container To become familiar.

Chapter 19 – Graphical User Interfaces

Chapter Goals To use layout managers to arrange user‑interface

components in a container To become familiar with common user-interface

components, such as radio buttons, check boxes, and menus

To build programs that handle events generated by user‑interface components

To browse the Java documentation effectively

In this chapter, you will learn how to use the most common user-interface components in the Java Swing toolkit, search Java documentation and handle events for interactive graphical programs.

Copyright © 2014 by John Wiley & Sons. All rights reserved.Page 2

Introduction A graphical user interface (GUI) presents a user-friendly

mechanism for interacting with an application.

Pronounced “GOO-ee”

GUIs are built from GUI components.

A GUI component is an object with which the user interacts via the mouse, the keyboard or another form of input, such as voice recognition.

Here, you’ll learn about many of Java’s so-called Swing GUI components from the javax.swing package.


IDE Support for GUI Design Many IDEs provide GUI design tools with which you can

specify a component’s exact size and location in a visual manner by using the mouse.

The IDE generates the GUI code for you.

Though this greatly simplifies creating GUIs, each IDE generates this code differently.

For this reason, we will write the GUI code by hand.


Sample Demo Download Swingset3 application and run:

download.java.net/javadesktop/swingset3/SwingSet3.jnlp

This application is a nice way for you to browse through the various GUI components provided by Java’s Swing GUI APIs.

Simply click a component name (e.g., JFrame, JTabbedPane, etc.) in the GUI Components area at the left of the window to see a demonstration of the GUI component in the right side of the window. The source code for each demo is shown in the text area at the bottom of the window.


From: Java How To Program – Dietel & Dietel

Page 6

The menus, buttons and combo box arepart of the application’s GUI.

They enable you to interact with the application.

Simple GUI-Based Input/Output with JOptionPane

Most applications you use on a daily basis use windows or dialog boxes (also called dialogs) to interact with the user.

Dialog boxes are windows in which programs display important messages to the user or obtain information from the user.

Java’s JOptionPane class (package javax.swing) provides prebuilt dialog boxes for both input and output.

Dialogs are displayed by invoking static JOptionPane methods.

Refer JavaDoc APICopyright © 2014 by John Wiley & Sons. All rights reserved.

Page 7


null = result in centering message in screen

Unlike Scanner, which can be used to input values of several types from theuser at the keyboard, an input dialog can input only Strings.

If the user clicks Cancel, showInputDialog returns null.

result in centering message in parent component

Programming Question Write a tester program Addition that takes two numbers as user input,

calculate sum and display calculated sum. Use JOptionPane to get user input and display sum.

Sample output is shown below:


Answer

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import javax.swing.JOptionPane; // program uses JOptionPane

public class Addition { public static void main( String[] args ) { // obtain user input from JOptionPane input dialogs String firstNumber = JOptionPane.showInputDialog( "Enter first integer" ); String secondNumber = JOptionPane.showInputDialog( "Enter second integer" );

// convert String inputs to int values for use in a calculation int number1 = Integer.parseInt( firstNumber ); int number2 = Integer.parseInt( secondNumber );

int sum = number1 + number2; // add numbers

// display result in a JOptionPane message dialog JOptionPane.showMessageDialog( null, "The sum is " + sum, "Sum of Two Integers", JOptionPane.PLAIN_MESSAGE ); } // end method main} // end class Addition

Addition.java

19.1 Layout Management Arranging components on the screen

User-interface components are arranged by placing them in a Swing Container object:

• Jframe, JPanel

• JFrame = a heavy weight container used as the top-level window

• JPanel = a light weight container used to organize GUI components


Jfrrame Class Example empty JFrame window:


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

public class Frame1 { public static void main(String[] args) { JFrame f = new JFrame("My First Frame"); // Create Frame

f.setSize(400,300); // Set size of frame f.setVisible(true); // Show the window } }

Output:


Example JFrame with a GUI object(Jlabel) added:


import java.awt.*; import javax.swing.*; public class Frame2 { public static void main(String[] args) { JFrame f = new JFrame("My First GUI"); f.setSize(400,300);

//create a label JLabel L = new JLabel("Hello World !");

//add label to frame f.getContentPane().add( L );

f.setVisible(true); } }

Output:


JPanel Class To display the JPanel, the JPanel must be added on to the JFrame !!!


import java.awt.*; import javax.swing.*; public class Frame3 { public static void main(String[] args) { JFrame f = new JFrame("JFrame with a JPanel"); JLabel L = new JLabel("Hello World !"); // Make a JLabel; JPanel P = new JPanel(); // Make a JPanel; P.add(L); // Add lable L to JPanel P f.getContentPane().add(P); // Add panel P to JFrame f f.setSize(400,300); f.setVisible(true); } }

Output:


Layout Management Each container has a layout manager that directs

the arrangement of its components Three useful layout managers are:

1) Border layout2) Flow layout3) Grid layout


Components are added to a container which uses a layout manager to place them

Jframe’s Content Pane

A JFrame has a content pane which is a Container where you can add components

Use the getContentPane method to get its reference

Adding components:

Add components to the content pane OR

Add a container to the content pane, then add components to the container

Container contentPane = getContentPane();


Jframe’s Content Pane (2) Frame

Menu Bar Content Pane

• Components• Container

– Components


Frame (with Title Bar)

Content Pane

x

Menu Bar (optional)

Container

Flow Layout Components are added from left to right

A JPanel uses flow layout by default

panel = new JPanel();panel.add(rateLabel);panel.add(rateField);panel.add(button);panel.add(resultLabel)

;


Example:

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import java.awt.*; import javax.swing.*; public class FlowLayoutDemo { public static void main(String[] args) { JFrame f = new JFrame("FlowLayoutDemo"); JPanel p = new JPanel(); FlowLayout layout = new FlowLayout(); layout.setHgap(50); layout.setVgap(50); p.setLayout(layout); p.add(new JLabel("One")); p.add(new JLabel("Two")); p.add(new JLabel("Three")); p.add(new JLabel("Four")); p.add(new JLabel("Five")); p.add(new JLabel("Six")); f.getContentPane().add(p); f.setSize(300,300); f.setVisible(true);

} }

Output:


Border Layout Components are placed toward areas of a

container NORTH, EAST, SOUTH, WEST, or CENTER Specify one when adding components

The content pane of a JFrame uses border layout by default

panel.setLayout(new BorderLayout());panel.add(component,

BorderLayout.NORTH);


Example


import java.awt.*; import javax.swing.*; public class BorderLayoutDemo { public static void main(String[] args) { JFrame f = new JFrame("BorderLayout Demo"); JPanel p = new JPanel(); BorderLayout layout = new BorderLayout(); p.setLayout(layout); p.add(new JButton("North"), BorderLayout.NORTH); p.add(new JButton("South") , BorderLayout.SOUTH); p.add(new JButton("West") , BorderLayout.WEST); p.add(new JButton("East") , BorderLayout.EAST); p.add(new JButton("Center") , BorderLayout.CENTER); f.getContentPane().add(p); f.setSize(500,500); f.setVisible(true);

} }

Sometimes we extend JFrame class to do the same:

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import javax.swing.JFrame;import javax.swing.JPanel;import java.awt.BorderLayout;import javax.swing.JButton;import javax.swing.SwingUtilities;

public class MyJFrame extends JFrame {

public MyJFrame() { setTitle("MyJFrame Example"); setSize(300, 200); setDefaultCloseOperation(EXIT_ON_CLOSE); JPanel p = new JPanel(); BorderLayout layout = new BorderLayout(); p.setLayout(layout); p.add(new JButton("North"), BorderLayout.NORTH); p.add(new JButton("South") , BorderLayout.SOUTH); p.add(new JButton("West") , BorderLayout.WEST); p.add(new JButton("East") , BorderLayout.EAST); p.add(new JButton("Center") , BorderLayout.CENTER); getContentPane().add(p); }

public static void main(String[] args) { MyJFrame ex = new MyJFrame(); ex.setVisible(true); }}

Output:


Grid Layout Components are placed in boxes in a simple table

arrangement Specify the size (rows then columns) of the grid

Then add components which will be placed from the upper left, across, then down

buttonPanel.add(button7);buttonPanel.add(button8);buttonPanel.add(button9);buttonPanel.add(button4);. . .

JPanel buttonPanel = new JPanel();buttonPanel.setLayout(new GridLayout(4,

3));


Example:

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import java.awt.*; import javax.swing.*; public class GridLayoutDemo { public static void main(String[] args) { JFrame f = new JFrame("GridLayout Demo"); JPanel p = new JPanel(); GridLayout layout = new GridLayout(4,3); p.setLayout(layout); p.add(new JButton("7")); p.add(new JButton("8")); p.add(new JButton("9")); p.add(new JButton("4")); p.add(new JButton("5")); p.add(new JButton("6")); p.add(new JButton("1")); p.add(new JButton("2")); p.add(new JButton("3")); p.add(new JButton("0")); p.add(new JButton(".")); p.add(new JButton("CE")); f.getContentPane().add(p); f.setSize(300,300); f.setVisible(true);

} }

Output:


Using Nested Panels Create complex layouts by nesting panels

Give each panel an appropriate layout manager Panels have invisible borders, so you can use as many

panels as you need to organize components

JPanel keypadPanel = new JPanel();keypadPanel.setLayout(new BorderLayout());buttonPanel = new JPanel();buttonPanel.setLayout(new GridLayout(4, 3));buttonPanel.add(button7);buttonPanel.add(button8);// . . .keypadPanel.add(buttonPanel,

BorderLayout.CENTER);JTextField display = new JTextField();keypadPanel.add(display, BorderLayout.NORTH);

JTextField in NORTH of keypadPanel

JPanel GridLayout in CENTER of keypadPanel


Example

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import java.awt.*; import javax.swing.*; public class CalculatorDemo { public static void main(String[] args) { JFrame f = new JFrame("Calculator Demo"); JPanel calculatorPanel = new JPanel(); BorderLayout bLayout = new BorderLayout(); calculatorPanel.setLayout(bLayout); //add display JTextField display = new JTextField(); calculatorPanel.add(display, BorderLayout.NORTH);

//add keypad JPanel keypadPanel = new JPanel(); GridLayout gLayout = new GridLayout(4,3); keypadPanel.setLayout(gLayout); keypadPanel.add(new JButton("7")); keypadPanel.add(new JButton("8")); keypadPanel.add(new JButton("9")); keypadPanel.add(new JButton("4")); keypadPanel.add(new JButton("5")); keypadPanel.add(new JButton("6")); keypadPanel.add(new JButton("1")); keypadPanel.add(new JButton("2")); keypadPanel.add(new JButton("3")); keypadPanel.add(new JButton("0")); keypadPanel.add(new JButton(".")); keypadPanel.add(new JButton("CE")); calculatorPanel.add(keypadPanel, BorderLayout.CENTER); f.getContentPane().add(calculatorPanel); f.setSize(300,300); f.setVisible(true); } }

Output:


Processing Text Input

Dialog boxes allows for user input… but Popping up a separate dialog box for each input is not a natural

user interface Most graphical programs collect text input through text

fields The JTextField class provides a text field

• When you construct a text field, supply the width:– The approximate number of characters that you expect– If the user exceeds this number, text will ‘scroll’ left

final int FIELD_WIDTH = 10;final JTextField rateField = new

JTextField(FIELD_WIDTH);


Add a Label and a Button A Label helps the user know what you want

Normally to the left of a textbox

A Button with an actionPerformed method can be used to read the text from the textbox with the getText method Note that getText returns a String, and must be converted to a numeric

value if it will be used in calculations

JLabel rateLabel = new JLabel("Interest Rate: ");

double rate = Double.parseDouble(rateField.getText());double interest = account.getBalance() * rate / 100;account.deposit(interest);resultLabel.setText("balance: " +

account.getBalance());Page 36

Programming Question Write a program InvestmentFrame2 that extends JFrame to

create following GUI. Application assumes an initial balance of $1000 and a default interest

rate of 5%. GUI should let user enter an interest rate. Clicking on “Add Interest

button” should print the updated balance

1. Start by defining constants:1. GUI constants: frame width, frame height

2. Application constants: default rate, initial balance

2. Define variables:1. GUI variables: rate label, rate text field, button, result label

2. Application variables: balance

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3. Create the GUI in no-argument constructor. 1. Initialize balance with initial balance

2. Create result label with initial balance

3. calls following 3 methods (you should implement) to implement GUI:– createButton(), createTextField(), createPanel()– createPanel method add all generated GUI comonents to panel.

4. Set size of frame

4. Write an inner class called AddInterestListener that implements ActionListener interface to handle action when button is pressed.

• Class has only one method: public void actionPerformed(ActionEvent event){

//code to get user input rate from GUI, calculate and display new balance

}

• CreateButton method should:– create the button – create object of AddInterestListener (say listener)– Add listener to button:

» button.addActionListener(listener);

• Download templatePage 38

http://www.users.csbsju.edu/~rdissanayaka/courses/f14/csci160/handouts/ch19/InvestmentFrame2.java

InvestmentFrame2.java skeleton

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public class InvestmentFrame2 extends JFrame{ /*** TODO: define constants **/ /*** TODO: define variables **/ //constructor public InvestmentFrame2() {

/*** TODO: initialize balance **//*** TODO: create result label **/ /*** TODO: create text field **//*** TODO: create button **//*** TODO: create panel**//*** TODO: set size of frame **/

}

private void createTextField() {

/*** TODO: create rate label **//*** TODO: create text field with default text **/

}

/** Inner class: Adds interest to the balance and updates the display. */ class AddInterestListener implements ActionListener { public void actionPerformed(ActionEvent event) { /*** TODO: get user, input rate, calculate and display updated balance in result label**/ } } private void createButton() { /*** TODO: create button **/ /*** TODO: create AddInterestActionListener object**/

/*** TODO: add this listener to button**/ }

private void createPanel() { /*** TODO: create panel **/ /*** TODO: GUI components to panel **/ /*** TODO: add panel to frame **/ } }

Test the created GUI using following tester class:


import javax.swing.JFrame;

/** This program displays the growth of an investment with variable interest.*/public class InvestmentViewer2{ public static void main(String[] args) { JFrame frame = new InvestmentFrame2(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }}

Answer


1 import java.awt.event.ActionEvent;2 import java.awt.event.ActionListener;3 import javax.swing.JButton;4 import javax.swing.JFrame;5 import javax.swing.JLabel;6 import javax.swing.JPanel;7 import javax.swing.JTextField;8 9 /**10 A frame that shows the growth of an investment with variable interest.11*/12public class InvestmentFrame2 extends JFrame13{ 14 private static final int FRAME_WIDTH = 450;15 private static final int FRAME_HEIGHT = 100;1617 private static final double DEFAULT_RATE = 5;18 private static final double INITIAL_BALANCE = 1000; 1920 private JLabel rateLabel;21 private JTextField rateField;22 private JButton button;23 private JLabel resultLabel;24 private double balance;25 26 public InvestmentFrame2()27 { 28 balance = INITIAL_BALANCE;2930 resultLabel = new JLabel("Balance: " + balance);3132 createTextField();33 createButton();34 createPanel();3536 setSize(FRAME_WIDTH, FRAME_HEIGHT);37 }38

InvestmentFrame2.java

Continued


39 private void createTextField()40 {41 rateLabel = new JLabel("Interest Rate: ");4243 final int FIELD_WIDTH = 10;44 rateField = new JTextField(FIELD_WIDTH);45 rateField.setText("" + DEFAULT_RATE);46 }4748 /**49 Adds interest to the balance and updates the display.50 */51 class AddInterestListener implements ActionListener52 {53 public void actionPerformed(ActionEvent event)54 {55 double rate = Double.parseDouble(rateField.getText());56 double interest = balance * rate / 100;57 balance = balance + interest;58 resultLabel.setText("Balance: " + balance);59 } 60 }61 62 private void createButton()63 {64 button = new JButton("Add Interest");65 66 ActionListener listener = new AddInterestListener();67 button.addActionListener(listener);68 }6970 private void createPanel()71 {72 JPanel panel = new JPanel();73 panel.add(rateLabel);74 panel.add(rateField);75 panel.add(button);76 panel.add(resultLabel); 77 add(panel);78 }

Text Areas

Create multi-line text areas with a JTextArea object

Set the size in rows and columns

Use the setText method to set the text of a text field or text area

final int ROWS = 10;final int COLUMNS = 30;JTextArea textArea = new JTextArea(ROWS,

COLUMNS);

textArea.setText(“Account Balance”);


Text Areas The append method adds text to the end of a text area

• Use newline characters to separate lines

Use the setEditable method to control user input


textArea.append(account.getBalance() + "\n");

textArea.setEditable(false);

JTextField and JTextArea JTextField and JTextArea inherit

from JTextComponent: setText setEditable


JTextField and JTextArea The append method is declared in the JTextArea class


To add scroll bars, use JScrollPane:JScrollPane scrollPane = new

JScrollPane(textArea);

Programming Question Modify InvestmentFrame2 (save as InvestmentFrame3) to

replace result label with a text area (with scroll bars). Every time the user clicks button, a new line should be added to text are showing updated total.

Test code:

Page 47


/** This program displays the growth of an investment. */public class InvestmentViewer3{ public static void main(String[] args) { JFrame frame = new InvestmentFrame3(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }}

Answer


1 import java.awt.event.ActionEvent;2 import java.awt.event.ActionListener;3 import javax.swing.JButton;4 import javax.swing.JFrame;5 import javax.swing.JLabel;6 import javax.swing.JPanel;7 import javax.swing.JScrollPane;8 import javax.swing.JTextArea;9 import javax.swing.JTextField;1011/**12 A frame that shows the growth of an investment with variable interest,13 using a text area.14*/15public class InvestmentFrame3 extends JFrame16{17 private static final int FRAME_WIDTH = 400;18 private static final int FRAME_HEIGHT = 250;19 20 private static final int AREA_ROWS = 10;21 private static final int AREA_COLUMNS = 30;2223 private static final double DEFAULT_RATE = 5;24 private static final double INITIAL_BALANCE = 1000; 25 26 private JLabel rateLabel;27 private JTextField rateField;28 private JButton button;29 private JTextArea resultArea;30 private double balance;31

Continued

InvestmentFrame3.java


32 public InvestmentFrame3()33 { 34 balance = INITIAL_BALANCE;35 resultArea = new JTextArea(AREA_ROWS, AREA_COLUMNS);36 resultArea.setText(balance + "\n");37 resultArea.setEditable(false);38 39 createTextField();40 createButton();41 createPanel();4243 setSize(FRAME_WIDTH, FRAME_HEIGHT);44 }4546 private void createTextField()47 {48 rateLabel = new JLabel("Interest Rate: ");4950 final int FIELD_WIDTH = 10;51 rateField = new JTextField(FIELD_WIDTH);52 rateField.setText("" + DEFAULT_RATE);53 }54

Continued


55 class AddInterestListener implements ActionListener56 {57 public void actionPerformed(ActionEvent event)58 {59 double rate = Double.parseDouble(rateField.getText());60 double interest = balance * rate / 100;61 balance = balance + interest;62 resultArea.append(balance + "\n");63 } 64 }6566 private void createButton()67 {68 button = new JButton("Add Interest"); 69 70 ActionListener listener = new AddInterestListener();71 button.addActionListener(listener);72 }7374 private void createPanel()75 {76 JPanel panel = new JPanel();77 panel.add(rateLabel);78 panel.add(rateField);79 panel.add(button);80 JScrollPane scrollPane = new JScrollPane(resultArea);81 panel.add(scrollPane); 82 add(panel);83 }84}

19.3 Choices

In a modern graphical user interface program, there are commonly used devices to make different types of selections:

Radio Buttons

• For a small set of mutually exclusive choices

Check Boxes

• For a binary choice

Combo Boxes• For a large set of choices


FontViewer Layout Title Bar Label

Shows current font

Combo Box Check Boxes Radio Buttons


Grouping Radio Buttons Add Radio Buttons into a ButtonGroup so that

only one button in the group is selected at a time Create the JRadioButtons first, then add them to the ButtonGroup

Note that the button group does not place the buttons close to each other on the container

JRadioButton smallButton = new JRadioButton("Small");

JRadioButton mediumButton = new JRadioButton("Medium");

JRadioButton largeButton = new JRadioButton("Large");

ButtonGroup group = new ButtonGroup();group.add(smallButton);group.add(mediumButton);group.add(largeButton);


Radio Button Panels Use a panel for each set of radio buttons

The default border for a panel is invisible (no border)

You can add a border to a panel to make it visible along with a text label:

There are a large number of border styles available

• See the Swing documentation for more details

JPanel panel = new JPanel();panel.add(smallButton);panel.add(mediumButton);panel.add(largeButton);panel.setBorder(new TitledBorder(new

EtchedBorder(),"Size"));


Selecting Radio Buttons It is customary to set one button as selected (the

default) when using radio buttons Use the button's setSelected method Set the default button before making the enclosing

frame visible

Call the isSelected method of each button to find out which one it is currently selected

JRadioButton largeButton = new JRadioButton("Large");

largeButton.setSelected(true);

if (largeButton.isSelected()) { size = LARGE_SIZE; }


Check Boxes versus Radio Buttons Radio buttons and check boxes have different

visual appearances

Radio buttons are round and

show a black dot when selected

Check boxes are square and

show a check mark when selected


Check Boxes

A check box is a user-interface component with two states: checked and unchecked

• Use for choices that are not mutually exclusive

– For example, text may be Italic, Bold, both or neither

• Because check box settings do not exclude each other, you do not need to place a set of check boxes inside a button group


Selecting Check Boxes

To setup a Check Box, use Swing JCheckBox Pass the constructor the name for the check box label

Call the isSelected method of a checkbox to find out whether it is currently selected or not

JCheckBox italicCheckBox = new JCheckBox("Italic");

if (italicCheckBox.isSelected()) { style = style + Font.ITALIC }


Combo Boxes A combo box is a combination of a list and a text

field Use a combo box for a large set of choices

• Use when radio buttons would take up too much space

It can also be editable• Type a selection into a blank line

When you click on the arrow to the right of the text field of a combo box, a list of selections drops down, and you can choose one of the items in the list

facenameCombo.setEditable();


Adding and Selecting Items Add text ‘items’ to a combo box that will show in

the list:

Use the getSelectedItem method to return the selected item (as an Object) Combo boxes can store other objects in addition to

strings, so casting to a string may be required:

JComboBox facenameCombo = new JComboBox();

facenameCombo.addItem("Serif");facenameCombo.addItem("SansSerif");. . .

String selectedString = (String) facenameCombo.getSelectedItem();


Programming Question Write a program FontFrame to create the following GUI: The font displayed should change when user select

different choices from combo box, checkboxes and radio buttons E.g. when user selects italics, text “Big Java ” should be displayed in

italics.


Serif, SansSerif, Monospaced

1. Create constants: frame width and frame height

2. Create variables:1. Label to display font “Big Java”

2. 2 Checkboxes : italics, bold

3. 3 Radiobuttons: small, medium, large

4. Combobox for font face name (Serif, SansSerif, Monospaced)

5. ActionListener to change display text based on user selections

3. Define no argument constructor1. Construct label with text “Big Java”

2. Add label to BorderLayout.CENTER

3. createControlPanel() : create checkboxes, radiobuttons, comboboxes add it to BorderLayout.SOUTH.

4. Set label font

5. Set size

4. Implement nested class ChoiceListener that implements ActionListener1. Actionperformed method will set the label font to current user choices

Download templatePage 62

http://www.users.csbsju.edu/~rdissanayaka/courses/f14/csci160/handouts/ch19/FontFrame.java

Test FontFrame class using following Tester class:

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/** This program allows the user to view font effects.*/public class FontViewer{ public static void main(String[] args) { JFrame frame = new FontFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setTitle("FontViewer"); frame.setVisible(true); }}

Answer1 import java.awt.BorderLayout;2 import java.awt.Font;3 import java.awt.GridLayout;4 import java.awt.event.ActionEvent;5 import java.awt.event.ActionListener;6 import javax.swing.ButtonGroup;7 import javax.swing.JButton;8 import javax.swing.JCheckBox;9 import javax.swing.JComboBox;10 import javax.swing.JFrame;11 import javax.swing.JLabel;12 import javax.swing.JPanel;13 import javax.swing.JRadioButton;14 import javax.swing.border.EtchedBorder;15 import javax.swing.border.TitledBorder;16 17 /**18 This frame contains a text sample and a control panel19 to change the font of the text.20 */21 public class FontFrame extends JFrame22 {23 private static final int FRAME_WIDTH = 300;24 private static final int FRAME_HEIGHT = 400;25 26 private JLabel label;27 private JCheckBox italicCheckBox;28 private JCheckBox boldCheckBox;29 private JRadioButton smallButton;30 private JRadioButton mediumButton;31 private JRadioButton largeButton;32 private JComboBox facenameCombo;33 private ActionListener listener;34 Page 64

FontFrame.java

Continued

Page 65

35 /**36 Constructs the frame.37 */38 public FontFrame()39 { 40 // Construct text sample41 label = new JLabel("Big Java");42 add(label, BorderLayout.CENTER);43 44 // This listener is shared among all components45 listener = new ChoiceListener();46 47 createControlPanel();48 setLabelFont();49 setSize(FRAME_WIDTH, FRAME_HEIGHT);50 }51 52 class ChoiceListener implements ActionListener53 { 54 public void actionPerformed(ActionEvent event)55 { 56 setLabelFont();57 }58 }59

Continued

60 /**61 Creates the control panel to change the font.62 */63 public void createControlPanel()64 {65 JPanel facenamePanel = createComboBox();66 JPanel sizeGroupPanel = createCheckBoxes();67 JPanel styleGroupPanel = createRadioButtons();68 69 // Line up component panels70 71 JPanel controlPanel = new JPanel();72 controlPanel.setLayout(new GridLayout(3, 1));73 controlPanel.add(facenamePanel);74 controlPanel.add(sizeGroupPanel);75 controlPanel.add(styleGroupPanel);76 77 // Add panels to content pane78 79 add(controlPanel, BorderLayout.SOUTH);80 }81 82 /**83 Creates the combo box with the font style choices.84 @return the panel containing the combo box85 */86 public JPanel createComboBox()87 {88 facenameCombo = new JComboBox();89 facenameCombo.addItem("Serif");90 facenameCombo.addItem("SansSerif");91 facenameCombo.addItem("Monospaced");92 facenameCombo.setEditable(true);93 facenameCombo.addActionListener(listener);94 95 JPanel panel = new JPanel();96 panel.add(facenameCombo);97 return panel;98 }

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Continued

99 100 /**101 Creates the check boxes for selecting bold and italic styles.102 @return the panel containing the check boxes103 */104 public JPanel createCheckBoxes()105 {106 italicCheckBox = new JCheckBox("Italic");107 italicCheckBox.addActionListener(listener);108109 boldCheckBox = new JCheckBox("Bold");110 boldCheckBox.addActionListener(listener);111112 JPanel panel = new JPanel();113 panel.add(italicCheckBox);114 panel.add(boldCheckBox);115 panel.setBorder(new TitledBorder(new EtchedBorder(), "Style"));116117 return panel;118 }119

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Continued

120 /**121 Creates the radio buttons to select the font size.122 @return the panel containing the radio buttons123 */124 public JPanel createRadioButtons()125 {126 smallButton = new JRadioButton("Small");127 smallButton.addActionListener(listener);128129 mediumButton = new JRadioButton("Medium");130 mediumButton.addActionListener(listener);131132 largeButton = new JRadioButton("Large");133 largeButton.addActionListener(listener);134 largeButton.setSelected(true);135136 // Add radio buttons to button group137138 ButtonGroup group = new ButtonGroup();139 group.add(smallButton);140 group.add(mediumButton);141 group.add(largeButton);142143 JPanel panel = new JPanel();144 panel.add(smallButton);145 panel.add(mediumButton);146 panel.add(largeButton);147 panel.setBorder(new TitledBorder(new EtchedBorder(), "Size"));148149 return panel;150 }

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Continued

151152 /**153 Gets user choice for font name, style, and size154 and sets the font of the text sample.155 */156 public void setLabelFont()157 { 158 // Get font name 159 String facename = (String) facenameCombo.getSelectedItem();160 161 // Get font style162 163 int style = 0;164 if (italicCheckBox.isSelected()) 165 { 166 style = style + Font.ITALIC; 167 }168 if (boldCheckBox.isSelected()) 169 { 170 style = style + Font.BOLD; 171 }172 173 // Get font size 174175 int size = 0;176 177 final int SMALL_SIZE = 24;178 final int MEDIUM_SIZE = 36;179 final int LARGE_SIZE = 48;180181 if (smallButton.isSelected()) { size = SMALL_SIZE; }182 else if (mediumButton.isSelected()) { size = MEDIUM_SIZE; }183 else if (largeButton.isSelected()) { size = LARGE_SIZE; }184 185 // Set font of text field186 187 label.setFont(new Font(facename, style, size)); 188 label.repaint();189 }190 }

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Steps to Design a User Interface

1) Make a sketch of the component layout.

Draw all the buttons, labels, text fields, and borders on a sheet of graph paper


Steps to Design a User Interface2) Find groupings of adjacent components with the same

layout.

Start by looking at adjacent components that are arranged top to bottom or left to right


Steps to Design a User Interface

3) Identify layouts for each group. For horizontal components, use flow Layout For vertical components, use a grid layout with one

column

4) Group the groups together. Look at each group as one blob, and group the blobs

together into larger groups, just as you grouped the components in the preceding step


Steps to Design a User Interface5) Write the code to generate the layout

JPanel radioButtonPanel = new JPanel();radioButtonPanel.setLayout(new GridLayout(3, 1));radioButton.setBorder(new TitledBorder(new EtchedBorder(), "Size"));radioButtonPanel.add(smallButton);radioButtonPanel.add(mediumButton);radioButtonPanel.add(largeButton);

JPanel checkBoxPanel = new JPanel();checkBoxPanel.setLayout(new GridLayout(2, 1));checkBoxPanel.add(pepperoniButton());checkBoxPanel.add(anchoviesButton());

JPanel pricePanel = new JPanel(); // Uses FlowLayout by defaultpricePanel.add(new JLabel("Your Price:"));pricePanel.add(priceTextField);

JPanel centerPanel = new JPanel(); // Uses FlowLayoutcenterPanel.add(radioButtonPanel);centerPanel.add(checkBoxPanel); // Frame uses BorderLayout by

default

add(centerPanel, BorderLayout.CENTER);add(pricePanel, BorderLayout.SOUTH);

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19.4 Menus A frame can contain a menu bar

Menu items can be added to each Menu or subMenu

public class MyFrame extends JFrame{ public MyFrame() { JMenuBar menuBar = new

JMenuBar(); setJMenuBar(menuBar); . . . } . . .}Copyright © 2014 by John Wiley & Sons. All rights reserved.

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Instantiate a menu bar, then add it to the frame with the setJMenuBar method.

MenuBar and Menu Items The MenuBar contains Menus

The container for the top-level Menu items is called a MenuBar• Add JMenu objects to the MenuBar

A Menu contains SubMenus and Menu items• A Menu item has no further SubMenus• You add Menu items and SubMenus with the add method

JMenuBar menuBar = new JMenuBar();JMenu fileMenu = new JMenu("File");JMenu fontMenu = new JMenu("Font");menuBar.add(fileMenu);menuBar.add(fontMenu);


Menu Item Events

Menu items generate action events when selected

Add action listeners only to menu items

• Not to menus or the menu bar

• When the user clicks on a menu name and a submenu opens, no action event is sent


Menu Item Events

Add action listeners to each Menu item

The listener is customized for each Menu item


ActionListener listener = new ExitItemListener();

exitItem.addActionListener(listener);

FaceEvent ActionListener (2)

Listener Inner Class version

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public JMenuItem createFaceItem(final String name)// Final variables can be accessed from an inner class method{ class FaceItemListener implements ActionListener { public void actionPerformed(ActionEvent event) { facename = name; // Accesses the local variable name setLabelFont(); } } JMenuItem item = new JMenuItem(name); ActionListener listener = new FaceItemListener(); item.addActionListener(listener); return item;}

1 import java.awt.BorderLayout;2 import java.awt.Font;3 import java.awt.event.ActionEvent;4 import java.awt.event.ActionListener;5 import javax.swing.JFrame;6 import javax.swing.JLabel;7 import javax.swing.JMenu;8 import javax.swing.JMenuBar;9 import javax.swing.JMenuItem;10 11 /**12 This frame has a menu with commands to change the font 13 of a text sample.14 */15 public class FontFrame2 extends JFrame16 {17 private static final int FRAME_WIDTH = 300;18 private static final int FRAME_HEIGHT = 400;19 20 private JLabel label;21 private String facename;22 private int fontstyle;23 private int fontsize;24 25 /**26 Constructs the frame.27 */

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Continued

28 public FontFrame2()29 { 30 // Construct text sample 31 label = new JLabel("Big Java");32 add(label, BorderLayout.CENTER);33 34 // Construct menu 35 JMenuBar menuBar = new JMenuBar(); 36 setJMenuBar(menuBar);37 menuBar.add(createFileMenu());38 menuBar.add(createFontMenu());39 40 facename = "Serif";41 fontsize = 24;42 fontstyle = Font.PLAIN;43 44 setLabelFont();45 setSize(FRAME_WIDTH, FRAME_HEIGHT);46 }47 48 class ExitItemListener implements ActionListener49 {50 public void actionPerformed(ActionEvent event)51 {52 System.exit(0);53 }54 } 55

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Continued

56 /**57 Creates the File menu.58 @return the menu59 */60 public JMenu createFileMenu()61 {62 JMenu menu = new JMenu("File");63 JMenuItem exitItem = new JMenuItem("Exit"); 64 ActionListener listener = new ExitItemListener();65 exitItem.addActionListener(listener);66 menu.add(exitItem);67 return menu;68 }69 70 /**71 Creates the Font submenu.72 @return the menu73 */74 public JMenu createFontMenu()75 {76 JMenu menu = new JMenu("Font");77 menu.add(createFaceMenu());78 menu.add(createSizeMenu());79 menu.add(createStyleMenu());80 return menu;81 } 82 83 /**84 Creates the Face submenu.85 @return the menu86 */87 public JMenu createFaceMenu()88 {89 JMenu menu = new JMenu("Face");90 menu.add(createFaceItem("Serif"));91 menu.add(createFaceItem("SansSerif"));92 menu.add(createFaceItem("Monospaced"));93 return menu;94 }

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Continued

95 96 /**97 Creates the Size submenu.98 @return the menu99 */100 public JMenu createSizeMenu()101 {102 JMenu menu = new JMenu("Size");103 menu.add(createSizeItem("Smaller", -1));104 menu.add(createSizeItem("Larger", 1));105 return menu;106 } 107108 /**109 Creates the Style submenu.110 @return the menu111 */112 public JMenu createStyleMenu()113 {114 JMenu menu = new JMenu("Style");115 menu.add(createStyleItem("Plain", Font.PLAIN));116 menu.add(createStyleItem("Bold", Font.BOLD));117 menu.add(createStyleItem("Italic", Font.ITALIC));118 menu.add(createStyleItem("Bold Italic", Font.BOLD+ Font.ITALIC));120 return menu;121 } 122

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Continued

123 /**124 Creates a menu item to change the font face and set its action listener.125 @param name the name of the font face126 @return the menu item127 */128 public JMenuItem createFaceItem(final String name)129 {130 class FaceItemListener implements ActionListener131 {132 public void actionPerformed(ActionEvent event)133 {134 facename = name;135 setLabelFont();136 }137 } 138139 JMenuItem item = new JMenuItem(name); 140 ActionListener listener = new FaceItemListener();141 item.addActionListener(listener);142 return item;143 }144

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Continued

145 /**146 Creates a menu item to change the font size147 and set its action listener.148 @param name the name of the menu item149 @param increment the amount by which to change the size150 @return the menu item151 */152 public JMenuItem createSizeItem(String name, final int increment)153 {154 class SizeItemListener implements ActionListener155 {156 public void actionPerformed(ActionEvent event)157 {158 fontsize = fontsize + increment;159 setLabelFont();160 }161 } 162 163 JMenuItem item = new JMenuItem(name); 164 ActionListener listener = new SizeItemListener();165 item.addActionListener(listener);166 return item;167 }

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Continued

168169 /**170 Creates a menu item to change the font style171 and set its action listener.172 @param name the name of the menu item173 @param style the new font style174 @return the menu item175 */176 public JMenuItem createStyleItem(String name, final int style)177 {178 class StyleItemListener implements ActionListener179 {180 public void actionPerformed(ActionEvent event)181 {182 fontstyle = style;183 setLabelFont();184 }185 } 186187 JMenuItem item = new JMenuItem(name); 188 ActionListener listener = new StyleItemListener();189 item.addActionListener(listener);190 return item;191 }192193 /**194 Sets the font of the text sample.195 */196 public void setLabelFont()197 { 198 Font f = new Font(facename, fontstyle, fontsize);199 label.setFont(f);200 }201} Page 85

Try it: ch19/section_4

JDesktopPane and JInternalFrame Allow you to display child windows inside main/parent windows

Create Desktop pane inside JFrame:

Create an internal frame:

or define a class that extend JInternalFrame and then:

JInternalFrame internalFrame = new LoginInternalFrame();

Add internal frame to Desktop pane:

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JDesktopPane theDesktop;theDesktop = new JDesktopPane(); add( theDesktop ); // add desktop pane to JFrame

JInternalFrame internalFrame = new JInternalFrame("Internal Frame", true, true, true, true );

theDesktop.add( internalFrame ); // attach internal frame


Programming Question Create a Jframe MainMenuFrame with a menu “File” that has a menu

item “Acess Internal Frame”. Clicking on this should create and display a internal frame

(JInternalFrame) displaying text “sample text” So the JInternalFrame should be created inside JMenuItem listener actionperformed

method Clicking on close button should close the internal frame. Write a main method to test your code.


Answer1 import java.awt.BorderLayout;2 import java.awt.Dimension;3 import java.awt.Graphics;4 import java.awt.event.ActionListener;5 import java.awt.event.ActionEvent;6 import java.util.Random;7 import javax.swing.JFrame;8 import javax.swing.JDesktopPane;9 import javax.swing.JMenuBar;10import javax.swing.JMenu;11import javax.swing.JMenuItem;12import javax.swing.JInternalFrame;13import javax.swing.JPanel;14import javax.swing.JLabel;15import javax.swing.ImageIcon;1617public class MainMenuFrame extends JFrame 18{19 private JDesktopPane theDesktop;20


Continued

21 // set up GUI22 public MainMenuFrame()23 {24 super( "Using a JDesktopPane" );2526 JMenuBar bar = new JMenuBar(); // create menu bar27 JMenu addMenu = new JMenu( "File" ); // create Add menu28 JMenuItem accessMenuItem = new JMenuItem( "AcessInternalFrame" );2930 addMenu.add( accessMenuItem ); // add new frame item to Add menu31 bar.add( addMenu ); // add Add menu to menu bar32 setJMenuBar( bar ); // set menu bar for this application3334 theDesktop = new JDesktopPane(); // create desktop pane35 add( theDesktop ); // add desktop pane to frame36


Continued

37 // set up listener for newFrame menu item38 accessMenuItem.addActionListener(3940 new ActionListener() // anonymous inner class41 { 42 // display new internal window43 public void actionPerformed( ActionEvent event ) 44 {45 // create internal frame46 JInternalFrame internalFrame = new JInternalFrame("Internal Frame", true, true, true, true );47 internalFrame.setTitle("Sample Internal Frame");48 internalFrame.setSize(500, 500);49 internalFrame.setDefaultCloseOperation(DISPOSE_ON_CLOSE);50 JPanel p = new JPanel(); 51 p.add(new JLabel("sample text"));52 53 internalFrame.getContentPane().add(p);54 55 internalFrame.add( p, BorderLayout.CENTER ); // add panel56 internalFrame.pack(); // set internal frame to size of contents5758 theDesktop.add( internalFrame ); // attach internal frame59 internalFrame.setVisible( true ); // show internal frame60 } 61 } 62 );63 } 64

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Continued

65 public static void main( String[] args )66 { 67 MainMenuFrame mainMenuFrame = new MainMenuFrame(); 68 mainMenuFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );69 mainMenuFrame.setSize( 600, 480 ); // set frame size70 mainMenuFrame.setVisible( true ); // display frame71 } 72}


Creating Password Text Create variable of type JPasswordField field:

JPasswordField passwordField;

Create JPasswordField object:passwordField = new JPasswordField( "Hidden text" );

Add ActionListner:passwordField.addActionListener( listener);

listener should check user name and password typed in by user matches entry in a password database or file.


Programming Question Create a main menu with one menu(File) and one menu item (Login). Clicking on the login button should display a Internal frame for login

implement LoginInternalFrame that extends InternaFrame The Login button should validate user against a logins.txt and display message

“successful login” or “unsuccessful login”

Hint:

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http://www.users.csbsju.edu/~rdissanayaka/courses/f14/csci160/handouts/ch19/logins.txt

Answerimport java.awt.BorderLayout;import java.awt.Dimension;import java.awt.Graphics;import java.awt.event.ActionListener;import java.awt.event.ActionEvent;import java.util.Random;import javax.swing.JFrame;import javax.swing.JDesktopPane;import javax.swing.JMenuBar;import javax.swing.JMenu;import javax.swing.JMenuItem;import javax.swing.JInternalFrame;import javax.swing.JPanel;import javax.swing.JLabel;import javax.swing.ImageIcon;

public class MainMenuFrame2 extends JFrame { private JDesktopPane theDesktop;


MainMenuFrame2.java

Continued

// set up GUI public MainMenuFrame2() { super( "Student Registration System" );

JMenuBar bar = new JMenuBar(); // create menu bar JMenu addMenu = new JMenu( "File" ); // create Add menu JMenuItem loignMenuItem = new JMenuItem( "Login" );

addMenu.add( loignMenuItem ); // add new frame item to Add menu bar.add( addMenu ); // add Add menu to menu bar setJMenuBar( bar ); // set menu bar for this application

theDesktop = new JDesktopPane(); // create desktop pane add( theDesktop ); loignMenuItem.addActionListener(// set up listener for newFrame menu item

new ActionListener() // anonymous inner class { // display new internal window public void actionPerformed( ActionEvent event ) { // create internal frame JInternalFrame internalFrame = new LoginInternalFrame(); internalFrame.setSize(500, 500); internalFrame.setDefaultCloseOperation(DISPOSE_ON_CLOSE); internalFrame.pack(); // set internal frame to size of contents

theDesktop.add( internalFrame); // attach internal frame internalFrame.setVisible( true ); // show internal frame } } ); }

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Continued

public static void main( String[] args ) { MainMenuFrame2 mainMenuFrame = new MainMenuFrame2(); mainMenuFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); mainMenuFrame.setSize( 600, 480 ); // set frame size mainMenuFrame.setVisible( true ); // display frame } }

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import java.awt.event.ActionListener;import java.awt.event.ActionEvent;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JButton;import javax.swing.JTextField;import javax.swing.JPasswordField;import javax.swing.JOptionPane;import javax.swing.JInternalFrame;import java.util.Scanner;import java.awt.GridLayout;import java.io.File;import java.util.Arrays;

public class LoginInternalFrame extends JInternalFrame { private JLabel userLabel; //user label private JTextField userTextField; // user text filed private JLabel passwordLabel; //user label private JPasswordField passwordField; // password field with text private JButton loginButton; //login button private JButton cancelButton; //cancel button String userName; char[] password;

LoginInternalFrame.java

Continued

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public LoginInternalFrame() { super("Login", true, true, true, true ); //setTitle("Login"); setLayout( new GridLayout(3,2) ); userLabel = new JLabel("User Name: "); passwordLabel = new JLabel("Password: "); userTextField = new JTextField( 10 ); passwordField = new JPasswordField( 10 ); loginButton = new JButton("Login"); cancelButton = new JButton("Cancel"); getContentPane().add(userLabel); getContentPane().add(userTextField); getContentPane().add(passwordLabel); getContentPane().add(passwordField); getContentPane().add(loginButton); getContentPane().add(cancelButton); LoginHandler handler = new LoginHandler(); loginButton.addActionListener( handler ); cancelButton.addActionListener( handler ); }

Continued

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private class LoginHandler implements ActionListener { // process textfield events public void actionPerformed( ActionEvent event ) {

if ( event.getSource() == loginButton ) { userName = userTextField.getText(); password = passwordField.getPassword(); boolean foundMatch = false; try { Scanner sc = new Scanner(new File("logins.txt")); while(sc.hasNext() && !foundMatch) { String[] entry = sc.next().split(","); System.out.println("user: "+userName+ " entry[0]: "+entry[0]); System.out.println("password: "+password+ " entry[1]: "+entry[1]); if( Arrays.equals (entry[0].toCharArray(), userName.toCharArray()) && Arrays.equals

(entry[1].toCharArray(), password)) { foundMatch = true; break; } }

Continued

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if(!foundMatch) { JOptionPane.showMessageDialog( null, "Unsuccessful Login","Failed Login",

JOptionPane.ERROR_MESSAGE ); userTextField.setText(""); passwordField.setText(""); } else { JOptionPane.showMessageDialog( null, "Successful Login","Successful Login",

JOptionPane.INFORMATION_MESSAGE ); setClosed( true ); } } catch(Exception e) { e.printStackTrace(); } } else if( event.getSource() == cancelButton ) { setVisible(false); } } } }

Project: Your project main menu window should ideally have only login menu item enabled. A User first select login menu item and login. Upon successful login, other menu items (register for course, enter grades etc.) should

be enabled. You can provide role based access to each user by also keeping a separate file:

• Sample entries:Tim, professor

James, Student

If Tim logs in successfully, for example, only certain menu items are enabled.• Enable enter grades menu item• Disable register for classes menu item

You can maintain a separate file which specify allowed operation for each role:• Sample entries:

professor: enterGrades,

student: registerSection, printGrades

Log off button can save what he did to necessary files and reset main menu frame to only enable login menu item.

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JLists A list displays a series of items from which

the user may select one or more items created with class JList supports :

Single-selection lists• allow only one item to be selected at a time

Multiple-selection lists• allow any number of items to be selected


// ListFrame.javaimport java.awt.FlowLayout;import java.awt.Color;import javax.swing.JFrame;import javax.swing.JList;import javax.swing.JScrollPane;import javax.swing.event.ListSelectionListener;import javax.swing.event.ListSelectionEvent;import javax.swing.ListSelectionModel;

public class ListFrame extends JFrame { private JList colorJList; // list to display colors private static final String[] colorNames = { "Black", "Blue", "Cyan", "Dark Gray", "Gray", "Green", "Light Gray", "Magenta", "Orange", "Pink", "Red", "White", "Yellow" }; private static final Color[] colors = { Color.BLACK, Color.BLUE, Color.CYAN, Color.DARK_GRAY, Color.GRAY, Color.GREEN, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE, Color.PINK, Color.RED, Color.WHITE, Color.YELLOW };

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ListFrame.java

Continued

public ListFrame() { super( "List Test" ); setLayout( new FlowLayout() ); // set frame layout

colorJList = new JList( colorNames ); // create with colorNames colorJList.setVisibleRowCount( 5 ); // display five rows at once // do not allow multiple selections colorJList.setSelectionMode( ListSelectionModel.SINGLE_SELECTION );

// add a JScrollPane containing JList to frame add( new JScrollPane( colorJList ) );

colorJList.addListSelectionListener( new ListSelectionListener() // anonymous inner class { // handle list selection events public void valueChanged( ListSelectionEvent event ) { getContentPane().setBackground( colors[ colorJList.getSelectedIndex() ] ); } // end method valueChanged } // end anonymous inner class ); // end call to addListSelectionListener } // end ListFrame constructor} // end class ListFrame

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JTabbedPane Arranges GUI components into layers, of which only one is

visible at a time. Users access each layer via a tab When the user clicks a tab, the appropriate layer is

displayed. The tabs appear at the top by default Any component can be placed on a tab.


import java.awt.BorderLayout;import java.awt.Color;import javax.swing.JFrame;import javax.swing.JTabbedPane;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.JButton;import javax.swing.SwingConstants;

public class JTabbedPaneFrame extends JFrame { // set up GUI public JTabbedPaneFrame() { super( "JTabbedPane Demo " ); JTabbedPane tabbedPane = new JTabbedPane(); // create JTabbedPane

// set up pane11 and add it to JTabbedPane JLabel label1 = new JLabel( "panel one", SwingConstants.CENTER ); JPanel panel1 = new JPanel(); // create first panel panel1.add( label1 ); // add label to panel tabbedPane.addTab( "Tab One", null, panel1, "First Panel" ); // set up panel2 and add it to JTabbedPane JLabel label2 = new JLabel( "panel two", SwingConstants.CENTER ); JPanel panel2 = new JPanel(); // create second panel panel2.add( label2 ); // add label to panel tabbedPane.addTab( "Tab Two", null, panel2, "Second Panel" );

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JTabbedPaneFrame.java

Continued

// set up panel3 and add it to JTabbedPane JLabel label3 = new JLabel( "panel three" ); JPanel panel3 = new JPanel(); // create third panel panel3.setLayout( new BorderLayout() ); // use borderlayout panel3.add( new JButton( "North" ), BorderLayout.NORTH ); panel3.add( new JButton( "West" ), BorderLayout.WEST ); panel3.add( new JButton( "East" ), BorderLayout.EAST ); panel3.add( new JButton( "South" ), BorderLayout.SOUTH ); panel3.add( label3, BorderLayout.CENTER ); tabbedPane.addTab( "Tab Three", null, panel3, "Third Panel" );

add( tabbedPane ); // add JTabbedPane to frame } // end JTabbedPaneFrame constructor}

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public class JTabbedPaneDemo{ public static void main( String[] args ) { JTabbedPaneFrame tabbedPaneFrame = new JTabbedPaneFrame(); tabbedPaneFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); tabbedPaneFrame.setSize( 300, 300 ); // set frame size tabbedPaneFrame.setVisible( true ); // display frame } // end main} // end class JTabbedPaneDemo

JTabbedPaneDemo.java

Find out more:

BoxLayout

GridBagLayout

Jpopup menus

Page 110

Chapter 19 – Graphical User Interfaces. Chapter Goals To use layout managers to arrange user ‑ interface components in a container To become familiar.

Documents

gui code

user interface components

graphical user interface

gui components area

various gui components

applications gui

user clicks

john wiley sons