Swing GUI

Swing Components and the Containment Hierarchy

Swing provides many standard GUI components such as buttons, lists, menus, and text areas, which you combine to create your program's GUI. It also includes containers such as windows and tool bars.

SwingApplication creates four commonly used Swing components:

a frame, or main window (JFrame) a panel, sometimes called a pane (JPanel) a button (JButton) a label (JLabel)

A diagram of the containment hierarchy for the window shown by

SwingApplication.

How to Make Frames (Main Windows)

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class FrameDemo {

public static void main(String s[]) {

JFrame frame = new JFrame("FrameDemo");

frame.addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e) {

System.exit(0); }

});

JLabel emptyLabel = new JLabel(""); emptyLabel.setPreferredSize(new Dimension(175, 100)); frame.getContentPane().add(emptyLabel, BorderLayout.CENTER); frame.pack();

frame.setVisible(true); }

}

JPanel

JPanel aPanel = new JPanel();aPanel.setLayout(new

BorderLayout());

Or

JPanel aPanel = new JPanel(new BorderLayout());

How to Use Buttons

To create a button, you can instantiate one of the many classes that descend from the AbstractButton class.

Class DescriptionJButton A common buttonJCheckBox A check box button. JRadioButton One of a group of radio buttonsJMenuItem An item in a menu. JCheckBoxMenuItem A menu item that has a checkbox.

JRadioButtonMenuItem A menu item that has a radio button

Button(JButton)

Normal Button MyButton= new JButton (“Click Me!”); pane.add(MyButton);

Image Button ImageIcon leftButtonIcon = new

ImageIcon(“flower.gif");

b1 = new JButton(“Bunga", leftButtonIcon);

Label (JLabel)

ImageIcon icon = new ImageIcon("images/middle.gif");

. . . label1 = new JLabel("Image and Text", icon,

JLabel.CENTER); //Set the position of the text, relative to the icon:

label1.setVerticalTextPosition(JLabel.BOTTOM); label1.setHorizontalTextPosition(JLabel.CENTER); label2 = new JLabel("Text-Only Label");

label3 = new JLabel(icon); //Add labels to the JPanel. add(label1); add(label2); add(label3);

Check Boxes

chinButton = new JCheckBox("Chin"); chinButton.setSelected(true);

glassesButton = new JCheckBox("Glasses"); glassesButton.setSelected(true);

hairButton = new JCheckBox("Hair"); hairButton.setSelected(true);

teethButton = new JCheckBox("Teeth"); teethButton.setSelected(true);

JPanel checkPanel = new JPanel(); checkPanel.setLayout(new GridLayout(0, 1)); checkPanel.add(chinButton); checkPanel.add(glassesButton); checkPanel.add(hairButton);

checkPanel.add(teethButton);

Example JCheckBox

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

public class KotakPilihan extends JApplet { private JCheckBox java, c cobol, vbscript, asp;

public void init() {Container pane = getContentPane();pane.setBackground(Color.white);pane.setLayout(new FlowLayout());

java = new JCheckBox (“Java”, true);pane.add(java);c = new JCheckBox (“C”);pane.add(c);cobol= new JCheckBox (“Cobol”);pane.add(cobol);vbscript = new JCheckBox (“Vbscript”);pane.add(vbscript);asp = new JCheckBox (“ASP”, true);pane.add(asp);}

}

Java C Cobol VBscript ASP

Radio Button

JRadioButton birdButton = new JRadioButton(“Bird”);

JRadioButton catButton = new JRadioButton(“Cat”);

JRadioButton dogButton = new JRadioButton(“Dog”);

dogButton.setSelected(true);JRadioButton rabbitButton = new

JRadioButton(“Rabbit”); JRadioButton pigButton = new

JRadioButton(“Pig”);

// Group the radio buttons. ButtonGroup group = new

ButtonGroup(); group.add(birdButton); group.add(catButton); group.add(dogButton); group.add(rabbitButton); group.add(pigButton);

List (JList) Define List

JList ShortList

String item[] = {“ one”, “two”,”three”,”four”,”five”,”six”}

ShortList = new JList(item);

ShortList.setVisibleRowCount(5);ShortList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

JScrollPane scroll = new JScrollPane(ShortList);

Example: JList

import java.awt.*;

import javax.swing.*;

public class Senarai extends JApplet{

Container pane = getContentPane();

JList bentuk;

String item [] = { “Garis”, “Segiempat”, “Bulatan”, ”Segitiga”, “Segienam”, “Segilapan”};

public void init() {pane.setBackground(Color.white);pane.setLayout (new FlowLayout());bentuk = new JList (item);bentuk.setVisibleRowCount (4);bentuk.setSelectionModel(ListSelectionModel.SINGLE_SELECTION);

JScrollPane skrol = new JScrollPane(bentuk);pane.add(skrol);

}}

Selecting Items in a List

SINGLE_SELECTION

Only one item can be selected at a time. When the user selects an item, any previously selected item is deselected first.

SINGLE_INTERVAL_SELECTION

Multiple, contiguous items can be selected. When the user begins a new selection range, any previously selected items are deselected first.

MULTIPLE_INTERVAL_SELECTION

The default. Any combination of items can be selected. The user must explicitly deselect items.

JComboBox

String[] petStrings = { "Bird", "Cat", "Dog", "Rabbit", "Pig" };

// Create the combo box, select item at index 4. JComboBox petList = new JComboBox(petStrings);

pane.add(petList) ;

JSlider

static final int FPS_INIT = 10; JSlider framesPerSecond = new

JSlider(JSlider.HORIZONTAL, 0, 30, FPS_INIT); framesPerSecond.setMajorTickSpacing(10);

framesPerSecond.setMinorTickSpacing(1); framesPerSecond.setPaintTicks(true); framesPerSecond.setPaintLabels(true);

//add the slider to the content pane contentPane.add(framesPerSecond);

JTextField

textField = new JTextField(20); textField.addActionListener(this);

... contentPane.add(textField);

JTextArea

JTextArea ruangTeks;

ruangTeks =new JTextArea(5,20);

JScrollPane skrol =new JScrollPane(ruangTeks,

JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,

JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

pane.add(skrol);

JPassword

JPasswordField passwordField = new JPasswordField(10);

passwordField.setEchoChar('#'); passwordField.addActionListener(new ActionListener()

{ ... }); ……private static boolean isPasswordCorrect(char[] input)

{ char[] correctPassword = { 'b', 'u', 'g', 'a', 'b', 'o', 'o' };

if (input.length != correctPassword.length) return false; for (int i = 0; i < input.length; i ++) if (input[i] != correctPassword[i]) return false; return true; }

BorderLayout Container contentPane = getContentPane();//Use the content pane's default BorderLayout. //contentPane.setLayout(new BorderLayout());

contentPane.add(new JButton("Button 1 (NORTH)"), BorderLayout.NORTH);

contentPane.add(new JButton("2 (CENTER)"), BorderLayout.CENTER); contentPane.add(newJButton("Button 3

(WEST)"), BorderLayout.WEST); contentPane.add(new JButton("Long-Named

Button 4 (SOUTH)"), BorderLayout.SOUTH); contentPane.add(new JButton("Button 5

(EAST)"), BorderLayout.EAST);

BoxLayout Container contentPane = getContentPane(); contentPane.setLayout(new

BoxLayout(contentPane, BoxLayout.Y_AXIS));

addAButton("Button 1", contentPane); addAButton("2", contentPane); addAButton("Button 3", contentPane); addAButton("Long-Named Button 4",

contentPane); addAButton("Button 5", contentPane);

CardLayout

CardLayout Program

JPanel cards; final static String BUTTONPANEL = "JPanel with

JButtons"; final static String TEXTPANEL = "JPanel with

JTextField"; public CardWindow() { Container contentPane = getContentPane(); //Put the JComboBox in a JPanel to get a nicer look. String comboBoxItems[] = { BUTTONPANEL,

TEXTPANEL }; JPanel cbp = new JPanel(); JComboBox c = new JComboBox(comboBoxItems); c.setEditable(false); c.addItemListener(this); cbp.add(c);

//Use the default layout manager, BorderLayout contentPane.add(cbp,

BorderLayout.NORTH); cards = new JPanel(); cards.setLayout(new CardLayout()); Jpanel p1 = new JPanel(); p1.add(new JButton("Button 1")); p1.add(new JButton("Button 2")); p1.add(new JButton("Button 3"));JPanel p2 = new JPanel(); p2.add(new JTextField("TextField", 20));cards.add(p1, BUTTONPANEL); cards.add(p2, TEXTPANEL); contentPane.add(cards,

BorderLayout.CENTER);

FlowLayout

Container contentPane = getContentPane(); contentPane.setLayout(new FlowLayout()); contentPane.add(new JButton("Button 1")); contentPane.add(new JButton("2")); contentPane.add(new JButton("Button 3")); contentPane.add(new JButton("Long-Named Button 4"));

contentPane.add(new JButton("Button 5"));

GridLayout

Container contentPane = getContentPane();contentPane.setLayout(new GridLayout(0,2)); contentPane.add(new JButton("Button 1")); contentPane.add(new JButton("2")); contentPane.add(new JButton("Button 3")); contentPane.add(new JButton("Long-Named

Button 4")); contentPane.add(new JButton("Button 5"));