Advanced Java Programming - Old Questions

6. What is the task of Layout manager? Describe about default layout manager. (1 +4)

The layout managers are used to arrange components in a particular manner. The Java LayoutManagers facilitates us to control the positioning and size of the components in GUI forms.

Border layout is the default layout manager for windows and dialog boxes.

Border Layout

The BorderLayout is used to arrange the components in five regions: north, south, east, west and center. Each region (area) may contain one component only.

Components of the BorderLayout Manager

·         BorderLayout.NORTH

·         BorderLayout.SOUTH

·         BorderLayout..EAST

·         BorderLayout.WEST

·         BorderLayout.CENTER

BorderLayout Constructors:

Example:

import java.awt.BorderLayout;  

import javax.swing.JButton;

import javax.swing.JFrame;

public class BorderLayoutExample {  

BorderLayoutExample(){  

    JFrame f=new JFrame();  

    JButton b1=new JButton("NORTH");;  

    JButton b2=new JButton("SOUTH");;  

    JButton b3=new JButton("EAST");;  

    JButton b4=new JButton("WEST");;  

    JButton b5=new JButton("CENTER");;  

    f.add(b1,BorderLayout.NORTH);  

    f.add(b2,BorderLayout.SOUTH);  

    f.add(b3,BorderLayout.EAST);  

    f.add(b4,BorderLayout.WEST);  

    f.add(b5,BorderLayout.CENTER);  

    f.setSize(300,300);  

    f.setVisible(true);  

}  

public static void main(String[] args) {  

    new BorderLayoutExample();  

}  

}