Core Java - [AWT BorderLayout Manager]

♠ Posted by Unknown in Core Java at 21:34

BorderLayout

The BorderLayout manager divides the window into five areas: East, South, West, North, and Center. Components are added to a BorderLayout by using add(String, Component). You can use one of the following two constructors to create a new BorderLayout.

                 

                  public BorderLayout(int hGap, int vGap)

This constructs a new BorderLayout with the specified horizontal and vertical gaps between the components.

                  public BorderLayout()

This constructs a new BorderLayout without horizontal or vertical gaps.

Example:

import java.awt.*;

import java.awt.event.*;

class ScrollMarquee extends Canvas

{

    private String message;

    private int x = 10; 

    private int y = 10;

    ScrollMarquee(String s)

    {

            message = s;

            repaint();

    }

    public void left()

    {

            if(x>10) x = x - 10;

            repaint();

    }

    public void right()

    {

            if(x<250) x = x + 10;

            repaint();

    }

    public void paint(Graphics g)

    {

            g.drawString(message, x, y);

    }

}

public class BorderLayoutExample extends Frame implements ActionListener 

{

    private Button btnLeft, btnRight, btnExit;

    private ScrollMarquee cObj;

    BorderLayoutExample()

    {

            btnLeft = new Button("Left");

            btnRight = new Button("Right");

            btnExit = new Button("Exit");

            cObj = new ScrollMarquee("My Canvas");

            cObj.setBackground(Color.yellow);

            cObj.setForeground(Color.black);

            Panel p = new Panel();

            p.setLayout(new FlowLayout());

            p.add(btnLeft);

            p.add(btnRight);

            p.add(btnExit);

            setLayout(new BorderLayout());

            add("Center",cObj);

            add("South", p);

            btnLeft.addActionListener(this);

            btnRight.addActionListener(this);

            btnExit.addActionListener(this);

    }

    public void actionPerformed(ActionEvent ae)

    {

            if(ae.getSource() == btnLeft)

            {

                    cObj.left();

            }

            else if(ae.getSource() == btnRight)

            {

                    cObj.right();

            }

            else if(ae.getSource() == btnExit)

            {

                    dispose();

                    System.exit(0);

            }

    }

    public static void main(String[] args) 

    {

            BorderLayoutExample f = new BorderLayoutExample();

            f.setVisible(true);

            f.setSize(300,200);

    }

}