Java –Swing

Creating  Windows & Applets

(lectures programs)

OnLine Documentations

Swing Tutorial

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Buttons: Show a variety of buttons.

JButton jb = new JButton("JButton");

BasicArrowButton up = new BasicArrowButton(BasicArrowButton.NORTH),

      To run, we may use one of the following methods:

% appletviewer Buttons.java

% appletviewer ButtonsFrame.html

% java Buttons

· Also use any browser and open: ButtonsFrame.html

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BASIC COMPONENTS

Buttons and Lables

JButton but = new JButton("Button 1");
but.setBackground(Color.red);
but.setEnabled(false);
 
ActionListener AL = new ActionListener() {...}
but.addActionListener(AL);
 
JLabel lab = new JLabel(“This is a Lebel”);
lab.setText("Hello");
 

TextFields

JTextField txt = new JTextField(30);
String s = new String();
s = txt.getText();
s = txt.getSelectedText();
txt.setText(" ");
 

TextAreas

JTextArea tar = new JTextArea(5, 20);
tar.setText(tar.getText()+ "Old Dominion University \n");
 

CheckBoxs

JCheckBox cb1 = new JCheckBox("Check Box 1");
if(cb.isSelected()) ..
 

RadioButtons

ButtonGroup grp = new ButtonGroup();
JRadioButton rb1 = new JRadioButton("one", false);
grb.add(rb1);
 

ComboBoxes

JComboBox cbox = new JComboBox();
cbox.addItem(description[count++]);
cbox.getSelectedIndex();
cbox.getSelectedItem());
 

Lists

DefaultListModel ListItems=new DefaultListModel();
JList List = new JList(ListItems);
 
ListItems.addElement(flavors[count++]);
Object[] items=List.getSelectedValues();
 
ListSelectionListener LL = new ListSelectionListener() {...}
list.addListSelectionListener(LL);
 

Borders

JPanel jp = new JPanel();
Border brd = new TitledBorder("Title");
// or new EtchedBorder();
// or new LineBorder(Color.blue);
// or …
jp.setBorder(brd);

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CONTROLLING  LAYOUT

Container cp = getContentPane();

FlowLayout

 
 cp.setLayout(new FlowLayout());

BorderLayout

cp.add(BorderLayout.NORTH, new JButton("North"));

GridLayout

cp.setLayout(new GridLayout(7,3));

BoxLayout

Box bh = Box.createHorizontalBox();
Box bv = Box.createVerticalBox();
 
bh.add(...);
cp.add(bh);
 
 

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COMPOUND COMPONENTS

Dailog Boxes

 
 JOptionPane.showMessageDialog(null, "There's a bug on you!", 
 "Message(Alert)!", JOptionPane.ERROR_MESSAGE);
 
 
 int answer = JOptionPane.showConfirmDialog(null, 
 "Quit? ", "Confirm(Yes/NO”", JOptionPane.YES_NO_OPTION);
 
 int sel = JOptionPane.showOptionDialog(null, "Choose a Color!",
 "Option(Color)", JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE,
  null, options, options[0]);
 
 String val = JOptionPane.showInputDialog("How many fingers do you see?");

Menus

 
JMenuBar mbar = new JMenuBar();
JMenu menu = new JMenu("Flavors");
JMenuItem item = new JMenuItem(flavors[i]);
menu.add(item);
mbar.add(menu);
setJMenuBar(mbar);
 
 

Popup

 
JPopupMenu popup = new JPopupMenu();
JMenuItem item = new JMenuItem(flavors[i]);
popup.add(item);
. . .
popup.show(. . .);
 

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Converting Applications to Applets

Application:

class A {}
class B {}
public class FileName { 
 public static void main(String[] args) {
 <main code>
}

Applete:

//<applet code = FileName width=600 height=250> </applet>

import com.bruceeckel.swing.*;

Make sure to modify CLASSPATH
e.g.,  in file .cshrc in UNIX,  to include where this package is
e.g.,  in UNIX /home/cs476/java/ThinkingInJava.2ndEditionR12/code

public class FileName extends JApplet {
 
 JTextArea Xout = new JTextArea (10, 30);
 
 public void init() { 
 
Container cp = getContentPane();
cp.setLayout(new FlowLayout());
cp.add(new JLabel("FileName"));
cp.add(new JScrollPane(Xout)); 
 
  <main code>
 
Anywhere inside the code of main or any other class:
 
replace: System.out.println("string");
 
with: Xout.append("string");   
 }
 
 class A {}
 class B {}
 
 public static void main(String[] args) {
 
 Console.run(new FileName(), 350, 250);
 
 }
}
 
To execute the program:
 
% java FileName
 
% appletviewer FileName.java
 
Alternatively: 
 
 Create a file called FileName.html that contains: 
 
<applet code=FileName width=600 height=250> </applet>
 
 Then use:
 % appletviewer FileName.html
 Or:
 open  FileName.html from within a browser
 
Example: 
 
Application: allother/SimpleThread.java 
 
Applet (and also application): applets/SimpleThread.java 
 
html: applets/SimpleThreadFrame.html 
 
The content of this file is:
 
<applet code=SimpleThread width=600 height=250> </applet>