infromation about j components

1. Aarti Narang
Jaskiran Kaur
Upneet Kaur

2. A swing is the primary JAVA GUI widget
toolkit , an API for providing a GUI for java
programs.
 Itwas developed to provide a more
sophisticated set of GUI components Other
than in AWT package.
 Supports more powerful and flexible
components that provides advanced and
pluggable look and feel.

3.  Platform independent
 Model –View-Controller
 Extensible
 Customizable
 Configurable
 Light weight UI

4. SWINGS AWT
 Light weighted  Heavy weighted
components. components.
 Completely written in  Uses of native
java. libraries.
 Better design than  Design issues are still
AWT. not good.
 Own look and feel.  Has to code properly.

6.  Java.awt.*
 Javax.swing.*
Javax : hierarchy of packages and set of
“light weight” components for platform-
independent rich GUI components.

7.  JApplet
 JButton
 JCheckBox Used for making swing applet
 JLabel instance.
 JComboBox
 JRadioButton
 JScrollPane
 JTabbedPane
 JTable
 JTree
 JTextField

8.  Swing labels are instances of JLabel class. It
can display text and/or an icon.
 Constructors are:
Jlabel(Icon i)
Jlabel(String s,Icon I,int align)
 Methods are:
Icon getIcon()
String getText()
Void setIcon(Icon i)
Void setText(String s)

9. Import java.awt.*;
Import javax.swing.*;
/* <applet code=“demo” width=200 height=200> </applet> */
public class demo extends JApplet {
public void init()
{
Container contentPane= getContentPane();
JLabel j1=new JLabel (“HELLO”,i1,JLabel.CENTER);
contentPane.add(j1);
}
}

10.  Swing image icons are instances of “ImageIcon”
class, which paints an icon from an image.
 Constructors are:
ImageIcon(URL url)
ImageIcon(String filename)
 Methods are:
int getIconHeight()
int getIconWidth()
void paintIcon(Component c, Graphics g, int x,int y)

11. Import java.awt.*;
Import javax.swing.*;
/* <applet code=“demo1” width=200 height=200> </applet> */
public class demo1 extends JApplet {
public void init()
{
Container contentPane= getContentPane();
ImageIcon i1= new ImageIcon(“1.gif”);
JLabel j1=new JLabel (“HELLO”,i1,JLabel.CENTER);
contentPane.add(j1);
}
}

12.  Swingtext field are instances of
JTextComponent class. It has one subclass
“JTextField” , for adding one line of text.
 Constructors are:
JTextField()
JTextField(int cols)
JTextField(String s,int cols)
JTextField(String s)

13. Import java.awt.*;
Import javax.swing.*;
/* <applet code=“demo3” width=200 height=200> </applet> */
public class demo3 extends JApplet {
JTextField jtf;
public void init()
{
Container contentPane= getContentPane();
jtf=new JJTextField(20);
contentPane.add(jtf);
}
}

14.  AbstractButton is a superclass for
checkboxes, push buttons and radio buttons.
 JButton subclass provides the functionality of a
push button.
 Constructors are:
JButton(Icon i)
JButton(String s,Icon i)
JButton(String s)

15. Import java.awt.*;
Import javax.swing.*;
/* <applet code=“demo2” width=200 height=200> </applet> */
public class demo2 extends JApplet {
public void init()
{
Container contentPane= getContentPane();
ImageIcon img=new ImageIcon(“2.gif”);
JButton jb1=new JButton(img);
contentPane.add(jb1);
JButton jb2=new JButton(“Click here”);
contentPane.add(jb2);
}
}

16.  JCheckBox class provides the functionality of a
checkbox. Its immediate superclass is
JToggleButton, which provides support for two state
buttons.
 Constructors are:
JCheckBox(Icon i)
JCheckBox(Icon i, Boolean b)
JCheckBox(String s)
JCheckBox(String s, Boolean b)
JCheckBox(String s,Icon i)
JCheckBox(String s,Icon I, Boolean b)
void setSelected(Boolean b)

17. Import java.awt.*;
Import javax.swing.*;
/* <applet code=“demo4” width=200 height=200> </applet> */
public class demo4 extends JApplet {
public void init()
{
Container contentPane= getContentPane();
JCheckBox cb=new JCheckBox(“C”,true);
contentPane.add(cb);
JCheckBox cb=new JCheckBox(“C++”,normal);
contentPane.add(cb);
JCheckBox cb=new JCheckBox(“Java”,normal);
contentPane.add(cb);
}
}

18.  Radio buttons are supported by JRadioButton
class, a subclass of AbstractButton.
 Constructors are same as of checkboxes.
 Radio
buttons must be grouped into one set, so
we use “ButtonGroup” class.
void add(AbstractButton b)

19. Import java.awt.*;
Import javax.swing.*;
/* <applet code=“demo5” width=200 height=200> </applet> *
public class demo5 extends JApplet {
public void init()
{
Container contentPane= getContentPane();
JRadioButton b1=new JRadioButton(“A”);
contentPane.add(b1);
JRadioButton b2=new JRadioButton(“A”);
contentPane.add(b2);
JRadioButton b3=new JRadioButton(“A”);
contentPane.add(b3);
ButtonGroup bg=new ButtonGroup();
bg.add(b1);
bg.add(b2);
bg.add(b3);
} }

20.  A tabbed pane is a component that appears as a group of
folders in a file cabinet. Each folder has title and is
selected one at a time.
 Tabbed panes are encapsulated by JTabbedPane class.
void addTab(String str, Component comp)
Procedure to use tabbed pane is:
 Create a JTabbedPane object.
 Call addtab() to add a tab to pane(title, and its
component for each tab).
 Repeat step 2 for each tab.
 Add tabbed pane to content pane of applet.
 Define subclasses for tabs.

21. public class demo6 extends JApplet {
public void init()
{
JTabbedPane tabs=new JTabbedPane();
Tabs.addTab(“Home”, new homemenu());
Tabs.addTab(“Insert”, new insertmenu());
Tabs.addTab(“View”, new viewmenu());
getContentPane().add(tabs);
}
}
class homemenu extends Jpanel {
public homemenu() {
---// buttons
}}
class insertmenu extends Jpanel {
public insertmenu() {
---// radio /checkboxes
}}

22.  A scroll pane is a component that presents a rectangular area in
which a component may be viewed horizontally or vertically.
 Scroll panes are encapsulated by JScrollPane class.
JScrollPane(Component comp)
JScrollPane(int v, int h)
JScrollPane(Component comp, int v, int h)
H and v are constants defined by ScrollPaneConstants
interface, as follows,
 HORIZONTAL_SCROLLBAR_ALWAYS
 HORIZONTAL_SCROLLBAR_AS_NEEDED
 VERTICAL_SCROLLBAR_ALWAYS
 VERTICAL_SCROLLBAR_AS_NEEDED

23. public class demo5 extends JApplet {
public void init()
{
Container contentPane= getContentPane();
contentPane.setLayout(new Borderlayout());
Jpanel jp =new Jpanel();
Jp.setLayout(
ButtonGroup bg=new ButtonGroup();
bg.add(b1);
bg.add(b2);
bg.add(b3);
} }

24.  A check box is a combination of text field and a drop-
down list.
 Check boxes are provided by JCheckBox class, which
extends JComponent.
JComboBox()
JComboBox(Vector v)
Here v is a vector that initializes the combo box.
 Items are added to list of choices via a method:
void addItem(Object obj)
Here obj is the object to be added to the combo box.

25. public class demo extends JApplet implements ItemListener
{
public void init()
{
Container contentPane= getContentPane();
JComboBox jc = new JComboBox();
jc.addItem(“Ludhiana”);
jc.addItem(“Chandigarh”);
jc.addItem(“Moga”);
jc.addItemListener (this);
contentPane.add(jc);
JLabel j1 =new JLabel(“ “);
contentPane.add(j1);
}
public void itemStateChanged(ItemEvent e)
{
String s=(String) i.getItem();
J1.setText(s);
}}