how to draw an arrow mark using java swing

[sandhyau]

how to draw an arrow mark in a straight line using java swing?.

[hardwired]

Code:

import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.*;

public class Arrow extends JPanel implements ChangeListener {
    Path2D.Double arrow = createArrow();
    double theta = 0;

    public void stateChanged(ChangeEvent e) {
        int value = ((JSlider)e.getSource()).getValue();
        theta = Math.toRadians(value);
        repaint();
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        int cx = getWidth()/2;
        int cy = getHeight()/2;
        AffineTransform at = AffineTransform.getTranslateInstance(cx, cy);
        at.rotate(theta);
        at.scale(2.0, 2.0);
        Shape shape = at.createTransformedShape(arrow);
        g2.setPaint(Color.blue);
        g2.draw(shape);
    }

    private Path2D.Double createArrow() {
        int length = 80;
        int barb = 15;
        double angle = Math.toRadians(20);
        Path2D.Double path = new Path2D.Double();
        path.moveTo(-length/2, 0);
        path.lineTo(length/2, 0);
        double x = length/2 - barb*Math.cos(angle);
        double y = barb*Math.sin(angle);
        path.lineTo(x, y);
        x = length/2 - barb*Math.cos(-angle);
        y = barb*Math.sin(-angle);
        path.moveTo(length/2, 0);
        path.lineTo(x, y);
        return path;
    }

    private JSlider getSlider() {
        JSlider slider = new JSlider(-180, 180, 0);
        slider.addChangeListener(this);
        return slider;
    }

    public static void main(String[] args) {
        Arrow test = new Arrow();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(test);
        f.add(test.getSlider(), "Last");
        f.setSize(400,400);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}

[sandhyau]

thanks for u r help. i have dought in the code. what is path2D. i am getting error in that .is it path2D is the seperate class?

[hardwired]

Path2D is new in j2se 1.6. For earlier versions use GeneralPath instead.

[sandhyau]

thank you.

[sandhyau]

i can draw an arrow mark in a line but the arrow is not rotating when the line moves. here i am placing the code . can any one help me that line should move as well as arrow mark should also move in the same direction.please send as soon as possible.thanks.

AffineTransform at = AffineTransform.getTranslateInstance((point2.x + point4.x)/2, (point2.y + point4.y)/2);
at.rotate(angle);
int length = 6;
int b = 10;
double angle = Math.toRadians(45);
GeneralPath path = new GeneralPath();
path.moveTo(5, 6);
path.moveTo(0,0);
// Double d = new Double(angle);
// int a = d.intValue();
int x = (int) (-b* Math.cos(angle));
int y = (int) (b * Math.sin(angle));
path.lineTo(x, y);
x = (int) (-b * Math.cos(-angle));
y = (int) (b * Math.sin(-angle));
path.moveTo(5, 6);
path.moveTo(0,0);
path.lineTo(x, y);
Shape shape = at.createTransformedShape(path);
// graphics2D.setPaint(Color.black);
graphics2D.draw(shape);
drawLine(graphics2D, point2.x, point2.y, point4.x, point4.y);