Java –Swing

Creating  Windows & Applets

(lectures programs)

OnLine Documentations

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

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");
 

Text Fields

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

Text Areas

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

Check Boxs

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

Radio Buttons

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

Combo Boxes

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);

CONTROLLING  LAYOUT

Container cp = getContentPane();

Flow Layout

cp.setLayout(new FlowLayout());

Border Layout

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

Grid Layout

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

Box Layout

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

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(. . .); 

Converting Applications to Applets

Application:

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

Applete:

Create a file called: FileName.html:

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

Modify FileName.java:

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 <main code> or any other class:
replace: System.out.println("string");
with: Xout.append("string");  
 }
 class A {}
 class B {}
}
 
To execute the program:
 
% appletviewer FileName.html
Or 
open  FileName.html from within a browser
 
Example 1: 
 
 Application: allother/Hello.java 
Applet: applets/Hello.java 
 html: applets/Hello.html 
 
 
Example 2: 
 
Application: allother/Shapes1.java 
 Applet: applets/Shapes1.java 
 html: applets/Shapes1.html