Notes on core java

1. Core Java
Debasish Pratihari
LayoutManager :

LayoutManager determines the way components
will be arranged inside the container.

All container’s have their default LayoutManger.

However You can apply a different
LayoutManager to the containers if required.

LayoutManager Classes are Provided in
java.awt and javax.swing package.
FlowLayoutManager :

FlowLayout Manager lays down the components
in a row and automatically spills components
onto the next row if row is full.

The default positing of the components is
centered in the container, and the default
orientation is from left to right.

Constants to Control FlowLayoutManager:
o LEFT
o RIGHT
o CENTER
o LEADING
TRAILING

Examples:

FlowLayout f= new FlowLayout();

FlowLayout f= new
FlowLayout(FlowLayout.LEFT);

FlowLayout f= new
FlowLayout(FlowLayout.LEFT,10,20);
Lecture/core/awt4/16
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2. Core Java
Debasish Pratihari
BorderLayoutManager:

The BorderLayoutManager divides the container
into file regions like
o EAST
o WEST
o NORTH
o SOUTH
o CENTER.

Each region can accommodate only one
component.
Example :
import java.awt.*;
class BorderTest extends Frame{
Button b1,b2,b3,b4,b5;
BorderTest(){
b1= new Button("EAST");
b2= new Button("WEST");
b3= new Button("NORTH");
b4= new Button("SOUTH");
b5=new Button("CENTER");
add(b1, BorderLayout.EAST);
add(b2,BorderLayout.WEST);
add(b3,BorderLayout.NORTH);
add(b4,BorderLayout.SOUTH);
add(b5,BorderLayout.CENTER);
setTitle("BorderDemo By Debasish Pratihari");
setSize(200,200);
setVisible(true);
}
public static void main(String args[]){
new BorderTest();
}
}
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3. Core Java
Debasish Pratihari
CardLayout:

The CardLayout manager arrange the
components in a stack, one on the top of
another.

The first component will be at the top, so will be
the only visible component.

Methods to operate CardLayout
o void previous(Container parent)
o void first (Container parent)
o void last(Container parent)
o void show(Container parent)
Example :
import java.awt.*;
import java.awt.event.*;
class CardTest extends Frame implements ActionListener{
Button b1,b2,b3,b4,b5;
CardLayout card;
CardTest(){
b1= new Button("JAVA");
b2= new Button("J2EE");
b3= new Button("C");
b4= new Button("C++");
b5=new Button("ORACLE");
card= new CardLayout(20,50);
setLayout(card);
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);
b4.addActionListener(this);
b5.addActionListener(this);
add(b1,"card
add(b2,"card
add(b3,"card
add(b4,"card
add(b5,"card
1");
2");
3");
4");
5");
setTitle("BorderDemo By Debasish Pratihari");
setSize(200,200);
setVisible(true);
}
public void actionPerformed(ActionEvent e){
card.next(this);
}
}
public static void main(String args[]){
new CardTest();
}
}
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4. Core Java
Debasish Pratihari
GridLayout:
 A GridLayout manager arranges components in
a rectangular grid within a container.
Constructors:

GridLayout()

GridLayout(int rows, int cols)

GridLayout(int
vgaps)
rows,int
cols,
int
hgaps,
int
Example :
import java.awt.*;
25%
Note :
class GridTest extends Frame {
GridTest(){
GridLayout layout= new GridLayout(3,3,10,10);
setLayout(layout);
for(int i=1;i<=9;i++)
add(new Button("Button "+i));
If you want the window
to assume the size that
just accommodates the
component it contains,
use pack()
setTitle("GridDemo By Debasish Pratihari");
setVisible(true);
pack();
}
public static void main(String ar[]){
new GridTest();
}
}
Output :
Lecture/core/awt4/16
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