GradientPaint

[Sean Mac Eoin]

Hi, trying to compile this piece of code from book *Java™ Media APIs: Cross-Platform Imaging, Media, and Visualization*.
The sucker refuses to compile, can anyone tell me why ?
Thanks in advance.
Compiler error below code.

-----------------------------------

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.JSlider;
import java.lang.StrictMath;
import java.awt.geom.Point2D.Double;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.Graphics2D;
import java.awt.GradientPaint;
import java.awt.BasicStroke;

public class GradientPaintEx extends JFrame {
    myCustomCanvas mc;
    JSlider p1slide, p2slide;
    JRadioButton cyclic_rb, acyclic_rb;

   public GradientPaintEx() {

         super("GradientPaint examples");
         BorderLayout f1 = new BorderLayout();  //layout manager for the frame

         mc = new myCustomCanvas(this);
         mc.setSize(500,500);
         mc.setPaint(100,200);

         addWindowListener(new WindowEventHandler());
   }


   class WindowEventHandler extends WindowAdapter {
      public void windowClosing(WindowEvent e) {
         System.exit(0);
      }
   }

   public static void main(String[] args) {
      new GradientPaintEx();
   }
}

class SliderListener implements ChangeListener {

    GradientPaintEx gex;
    myCustomCanvas mc;
    int slider_val;

  public SliderListener(GradientPaintEx gex, myCustomCanvas mc) {
        this.gex = gex;
        this.mc = mc;
  }

  public void stateChanged(ChangeEvent e) {

    int p1pos = gex.p1slide.getValue();
    int p2pos = gex.p2slide.getValue();

    mc.setPaint(p1pos,p2pos);

   }//End of stateChanged
 }//End of SliderListener

class myCustomCanvas extends Canvas {
       GradientPaintEx gex;
       double p1pos, p2pos;
		GradientPaint gpaint;
		Point2D x;
		Point2D y;

      public myCustomCanvas(GradientPaintEx gex) {

         this.gex = gex;
      }

    public void setPaint(int p1pos, int p2pos) {
        this.p1pos = (double) p1pos;
        this.p2pos = (double) p2pos;

        boolean cycle = true;
        if (gex.cyclic_rb.isSelected())
           cycle = true;
        else
           cycle = false;
           Point2D.Double x = new Point2D.Double(p1pos,
                                        this.getSize().height/2);

           Point2D.Double y = new Point2D.Double(p2pos,
                                        this.getSize().height/2);

          gpaint = new GradientPaint(x, y, Color.red, Color.green, cycle);  // <<<<ERROR !!
        repaint();
      }

       public void update(Graphics g) {
          paint(g);
       }

      public void paint(Graphics g) {

          gex.p1slide.setMaximum(this.getSize().width);
          gex.p2slide.setMaximum(this.getSize().width);

          Graphics2D g2d = (Graphics2D) g;

          g2d.setPaint(gpaint); //setting context

          g2d.fill(new Rectangle2D.Double(0,
                                          0,
                                          this.getSize().width,
                                          this.getSize().height));

          g2d.setColor(Color.black);
          BasicStroke stroke = new BasicStroke(4);
          g2d.setStroke(stroke);
          Line2D line1 = new Line2D.Double(p1pos,
                                           0,
                                           p1pos,
                                           this.getSize().height);
          g2d.draw(line1);

          Line2D line2 = new Line2D.Double(p2pos,
                                           0,
                                           p2pos,
                                           this.getSize().height);
          g2d.draw(line2);
          // step two-set the graphics context


      }
}

----------------------------------------

GradientPaintEx.java:92: cannot find symbol
symbol  : constructor GradientPaint(java.awt.geom.Point2D.Double,java.awt.geom.Point2D.Double,java.awt.Color,java.awt.Color,boolean)
location: class java.awt.GradientPaint
          gpaint = new GradientPaint(x, y, Color.red, Color.green, cycle);

[Rob Spoor]

If you check the API of GradientPaint you will see that the parameter order is Point2D, Color, Point2D, Color, boolean. You're providing them as Point2D, Point2D, Color, Color, boolean. Swap the second and third arguments and the code should compile.

And please UseCodeTags next time.

[Sridhar Santhanakrishnan]

The order of the arguments is wrong.

java.awt.GradientPaint.GradientPaint(Point2D pt1, Color color1, Point2D pt2, Color color2, boolean cyclic)

This should work -

gpaint = new GradientPaint(x, Color.red, y, Color.green, cycle);

<edit> took too long to get my post in </edit>

[Sean Mac Eoin]

Thanks all.