Drawing surface

Question

I have a small program, and right now it's just the interface. This one is suppose to plot polynomials, but my drawing surface isn't showing up. I'll post the code for the drawing surface, which is an external class, if needed, I will post the whole thing.
import java.awt.image.*;
import java.awt.*;
import javax.swing.*;
public class ImagePlotter extends JPanel
     BufferedImage cartisianImage;
     Graphics2D g2d;
     public ImagePlotter()
     public void paintComponent(Graphics g)
          g2d = (Graphics2D)g;
          int width = 300;
          int height = 300;
          cartisianImage = (BufferedImage)(this.createImage(width,height));
          Graphics2D gc = cartisianImage.createGraphics();
          g2d.drawImage(cartisianImage,null,0,0);
     public void drawPolynomialLine(int[] xPoints, int[] yPoints, int count)
          g2d.drawPolyline(xPoints,yPoints, count);
          repaintComponent();
     public void repaintComponent()
          repaint();
}In the "driver" class, I do this:
ImagePlotter ip = new ImagePlotter();
//then i add it to the container
pane.add(ip);

Answer 1

Why use a buffered image? You can make that work, but it's generally easier and just as effective to do the drawing in your paintComponent() method.
Try adding this to your ImagePlotter() constructor:
setPreferredSize( new Dimension(300, 300) );Then your enclosing JFrame can just pack() and it should come out all right.
In your paintComponent() method, discard the image and just call your draw method. But try something simple, to make sure the driver and drivee are working together. Something like this in paintComponent():
g.setColor( Color.BLUE );
g.fillRect( 10, 10, 100, 100 );When that works, get on to debugging the real draw code. And since you'll be calling the draw code from paintComponent(), discard repaintComponent() and the call to it in drawPolynumialLine().
Good luck!