Clip Area

This section illustrates you how to show the clipping of Area.

A Clip is a portion of a graphics or video or any picture. We are providing you an example which shows the clipping of area.

In the given example, we have defined two buttons clip1 and clip2 to perform two actions. On clicking clip1, a Rectangle2D class shows the clip of rectangular area and on clicking clip2, Rectangle class (subclass of Rectangle2D) shows a rectangle inside the rectangular area. The method setClip() sets the clipping area to clip the shape.

Here is the code of ClipAreaExample.java


import java.awt.*;

import javax.swing.*;

import java.awt.geom.*;

import java.awt.event.*;

import javax.swing.border.TitledBorder;

      

public class ClipAreaExample extends JFrame {

  Canvas1 canvas;

  JButton button1, button2;

    public ClipAreaExample() {

    super("Clip Area");

    Container contentPane = getContentPane();

    canvas = new Canvas1();

    contentPane.add(canvas);

    JPanel panel = new JPanel();

    panel.setLayout(new GridLayout(1, 2));

    button1 = new JButton("Clip1");

    button1.addActionListener(new ActionListener() {

      public void actionPerformed(ActionEvent event) {

        canvas.clip1 = true;

        canvas.clip2= false;

        canvas.repaint();

      }

    });

    button2 = new JButton("Clip2");

    button2.addActionListener(new ActionListener() {

      public void actionPerformed(ActionEvent event) {

        canvas.clip2 = true;

        canvas.repaint();

      }

    });

    ButtonGroup buttonGroup = new ButtonGroup();

    buttonGroup.add(button1);

    buttonGroup.add(button2);

    panel.add(button1);

    panel.add(button2);

    contentPane.add(BorderLayout.SOUTH, panel);

    addWindowListener(new WindowAdapter() {

    public void windowClosing(WindowEvent event) {

        System.exit(0);

      }

    });

    setVisible(true); 

  }

  public static void main(String arg[]) {

    new ClipAreaExample();

  }

}

class Canvas1 extends JPanel{

  boolean clip1 = true;

  boolean clip2 = false;

  Canvas1() {

    setSize(450, 400);

    setBackground(Color.white);

  }

  public void paint(Graphics g) {

    Graphics2D g2d = (Graphics2D) g;

    int wi = getSize().width;

    int ht = getSize().height;

    if (clip1) {

      Rectangle2D rectangle = new Rectangle2D.Double(wi / 4.0f,

             ht / 4.0f,
      wi / 2.0f,ht / 2.0f);

      g2d.setClip(rectangle);

      g2d.setColor(Color.cyan);

      g2d.fillRect(0, 0, wi, ht);

    }

  if (clip2) {

      Rectangle rect = new Rectangle(wi / 2, ht / 2, wi / 2, ht / 2);

      g2d.clip(rect);

      g2d.setColor(Color.red);

      g2d.fillRect(0, 0, wi, ht);

    }

  }

}

Output will be displayed as:

On clicking clip2 button, a rectangle is shown inside the rectangular area:

Download Source code