Adding an ActionListener to a drawn Circle

[aortell24]

Hello all, I am trying to write a program that creates a random color circle in a random location and when the user clicks the circle with the mouse the circle disappears and reappear in another random location and another random color. My question is how do I add the NewCircleListener to the circle? Every time I try adding it it acts like the NewCircleListener does not exsit.Saying "cannot resolve NewCircleListener symbol", I am not looking for anyone to write my code for me just some pointers would be greatly appreciated.Thanks alot.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
/**
 * Created with IntelliJ IDEA.
 * User: root
 * Date: 6/3/12
 * Time: 7:27 PM
 * To change this template use File | Settings | File Templates.
 */
public class Exercise16_27 extends JFrame {
    NewPanel panel = new NewPanel();
    Exercise16_27()
    {
       add(panel);
    }
    public static void main(String[] args)
    {
        Exercise16_27 frame = new Exercise16_27();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.setSize(600, 600);
        frame.setTitle("Circle Game");
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);

    }
    class NewPanel extends JPanel {
        int _xPoint = ((int)(Math.random()* 500));
        int _yPoint = ((int)(Math.random()* 500));
        NewPanel()
        {

        }
        protected void paintComponent(Graphics g)
        {
            int _radius = 10;
            super.paintComponents(g);
            g.fillOval(_xPoint, _yPoint, _radius, _radius);
            g.setColor(getRandomColor());

        }

        public Color getRandomColor()
        {
            Random numGen = new Random();
            return new Color(numGen.nextInt(256), numGen.nextInt(256), numGen.nextInt(256));
        }
        class NewCircleListener implements ActionListener
        {
            public void actionPerformed(ActionEvent event)
            {
                _xPoint = ((int)(Math.random()* 500));
                _yPoint = ((int)(Math.random()* 500));
                repaint();

            }
        }

    }

}

[KevinWorkman]

You can't just put an ActionListener on a circle, that doesn't make a ton of sense. Use a MouseListener on the JPanel and check the location of the click against any circles you want to monitor.

[aortell24]

Okay, I added the mouse Listener instaed of the NewCircleListener but it now draws the random circle when I click anywhare on the panel but doesnot remove the old circle
and the color does not change.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
/**
 * Created with IntelliJ IDEA.
 * User: root
 * Date: 6/3/12
 * Time: 7:27 PM
 * To change this template use File | Settings | File Templates.
 */
public class Exercise16_27 extends JFrame {
    NewPanel panel = new NewPanel();
    Exercise16_27()
    {
       add(panel);
    }
    public static void main(String[] args)
    {
        Exercise16_27 frame = new Exercise16_27();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.setSize(600, 600);
        frame.setTitle("Circle Game");
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);

    }
    class NewPanel extends JPanel {
        int _xPoint = ((int)(Math.random()* 500));
        int _yPoint = ((int)(Math.random()* 500));
        NewPanel()
        {
          addMouseListener(new MouseListener() {
              @Override
              public void mouseClicked(MouseEvent mouseEvent)
              {
                  _xPoint = ((int)(Math.random()* 500));
                  _yPoint = ((int)(Math.random()* 500));
                  repaint();

              }

              @Override
              public void mousePressed(MouseEvent mouseEvent)
              {

              }
              @Override
              public void mouseReleased(MouseEvent mouseEvent)
              {
                  repaint();

              }

              @Override
              public void mouseEntered(MouseEvent mouseEvent)
              {

              }

              @Override
              public void mouseExited(MouseEvent mouseEvent) {
                  //To change body of implemented methods use File | Settings | File Templates.
              }
          });
        }
        protected void paintComponent(Graphics g)
        {
            int _radius = 10;
            super.paintComponents(g);
            g.fillOval(_xPoint, _yPoint, _radius, _radius);
            g.setColor(getRandomColor());

        }

        public Color getRandomColor()
        {
            Random numGen = new Random();
            return new Color(numGen.nextInt(256), numGen.nextInt(256), numGen.nextInt(256));
        }
        class NewCircleListener implements ActionListener
        {
            public void actionPerformed(ActionEvent event)
            {


            }
        }

    }

}

[KevinWorkman]

You need to call super.paintComponent() from your paintComponent() method, not super.paintComponents() - notice the extra 's'.

You also aren't checking the mouse position against any circle positions, so that's going to trigger no matter where you click.

[JosAH]

You can't add an ActionListener to some random drawing; you should add a MouseListener to that JPanel and when its appropriate method is called, it should check where the mouse was pressed and take its action(s).

kind regards,

Jos

edit: way too slow as always ...

[aortell24]

Thanks guys.

[aortell24]

I got it just one more question if you don't mind is my getRandomColor() not correct because its not changing colors.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
/**
 * Created with IntelliJ IDEA.
 * User: root
 * Date: 6/3/12
 * Time: 7:27 PM
 * To change this template use File | Settings | File Templates.
 */
public class Exercise16_27 extends JFrame {
    NewPanel panel = new NewPanel();
    int _radius = 10;
    Exercise16_27()
    {
       add(panel);
    }
    public static void main(String[] args)
    {
        Exercise16_27 frame = new Exercise16_27();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.setSize(600, 600);
        frame.setTitle("Circle Game");
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);

    }
    class NewPanel extends JPanel {
        int _xPoint = ((int)(Math.random()* 500));
        int _yPoint = ((int)(Math.random()* 500));
        NewPanel()
        {
          addMouseListener(new MouseListener() {
              @Override
              public void mouseClicked(MouseEvent mouseEvent)
              {
                  if(insideCircle(mouseEvent.getX(), mouseEvent.getY()))
                  {

                    _xPoint = ((int)(Math.random()* 500));
                    _yPoint = ((int)(Math.random()* 500));
                    repaint();
                  }
              }

              @Override
              public void mousePressed(MouseEvent mouseEvent)
              {

              }
              @Override
              public void mouseReleased(MouseEvent mouseEvent)
              {
                  repaint();

              }

              @Override
              public void mouseEntered(MouseEvent mouseEvent)
              {

              }

              @Override
              public void mouseExited(MouseEvent mouseEvent) {
                  //To change body of implemented methods use File | Settings | File Templates.
              }
          });
        }
        protected void paintComponent(Graphics g)
        {

            super.paintComponent(g);
            g.fillOval(_xPoint, _yPoint, _radius, _radius);
            g.setColor(getRandomColor());

        }
        public boolean insideCircle(int px,int py)
        {
           return distance(px, py, _xPoint, _yPoint) < _radius;
        }
        public double distance(double x1, double y1, double x2, double y2)
        {
            return Math.sqrt((x2 -x1)* (x2 -x1) + (y2 - y1) * (y2 - y1));
        }
        public Color getRandomColor()
        {
            Random numGen = new Random();
            return new Color(numGen.nextInt(256), numGen.nextInt(256), numGen.nextInt(256));
        }

    }

}

[Fubarable]

I got it just one more question if you don't mind is my getRandomColor() not correct because its not changing colors.

Oh, it is changing colors just fine -- but when do you call it in on the Graphics object in relation to when you use the Graphics object to draw something?

[KevinWorkman]

You're setting the color after you draw the circle. That's a bit like dipping your brush in paint only after painting a picture.

[aortell24]

Duh, Thanks alot guys. I really appreciate all the help.You guys always answer so quick every other forum I belong to usually takes days to get any answers.

[aortell24]

Sorry to bother you guys again but I am trinyg to add another circle for fun I got it to show up and change colors but it will not move do I need to add another mouse Listener?

 import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.Random;

/**
 * Created with IntelliJ IDEA.
 * User: root
 * Date: 6/4/12
 * Time: 1:21 PM
 * To change this template use File | Settings | File Templates.
 */
class NewPanel extends JPanel {
    int _xPoint = ((int)(Math.random()* 500));
    int _yPoint = ((int)(Math.random()* 500));
    int _xPoint1 = ((int)(Math.random()* 500));
    int _yPoint1 = ((int)(Math.random()* 500));
    int _radius = 30;
    NewPanel()
    {
        setBackground(Color.BLUE);
        addMouseListener(new MouseListener() {
            @Override
            public void mouseClicked(MouseEvent mouseEvent)
            {
                if(insideCircle(mouseEvent.getX(), mouseEvent.getY()))
                {
                    _xPoint = ((int)(Math.random()* 500));
                    _yPoint = ((int)(Math.random()* 500));
                    repaint();
                }



                if(insideCircle1(mouseEvent.getX(), mouseEvent.getY()))
                {
                    _xPoint1 = ((int)(Math.random()* 500));
                    _yPoint1 = ((int)(Math.random()* 500));
                    repaint();
                }
            }
            @Override
            public void mousePressed(MouseEvent mouseEvent)
            {
                //To change body of implemented methods use File | Settings | File Templates.
            }
            @Override
            public void mouseReleased(MouseEvent mouseEvent)
            {
                //To change body of implemented methods use File | Settings | File Templates.
            }
            @Override
            public void mouseEntered(MouseEvent mouseEvent)
            {
                //To change body of implemented methods use File | Settings | File Templates.
            }
            @Override
            public void mouseExited(MouseEvent mouseEvent)
            {
                //To change body of implemented methods use File | Settings | File Templates.
            }
        });
    }
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        g.setColor(getRandomColor());
        g.fillOval(_xPoint, _yPoint, _radius, _radius);

        g.setColor(getRandomColor());
        g.fillOval(_xPoint1, _yPoint1, _radius, _radius);

    }
    public boolean insideCircle(int px,int py)
    {
        return distance(px, py, _xPoint, _yPoint) < _radius;
    }
    public double distance(double x1, double y1, double x2, double y2)
    {
        return Math.sqrt((x2 -x1)* (x2 -x1) + (y2 - y1) * (y2 - y1));
    }
    public boolean insideCircle1(int px1,int py1)
    {
        return distance1(px1, py1, _xPoint, _yPoint) < _radius;
    }
    public double distance1(double x1, double y1, double x2, double y2)
    {
        return Math.sqrt((x2 -x1)* (x2 -x1) + (y2 - y1) * (y2 - y1));
    }
    public Color getRandomColor()
    {
        Random numGen = new Random();
        return new Color(numGen.nextInt(256), numGen.nextInt(256), numGen.nextInt(256));
    }
}

[KevinWorkman]

I think you should test your assumptions. Does your code really determine whether the mouse is inside a circle? Hint: How are the x and y values passed into fillOval() used? What about "radius"?

You might also want to check out the Math class.

[aortell24]

Is this what you mean ?

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.Random;

/**
 * Created with IntelliJ IDEA.
 * User: root
 * Date: 6/4/12
 * Time: 1:21 PM
 * To change this template use File | Settings | File Templates.
 */
class NewPanel extends JPanel {
    int _xPoint = ((int)(Math.random()* 500));
    int _yPoint = ((int)(Math.random()* 500));
    int _xPoint1 = ((int)(Math.random()* 500));
    int _yPoint1 = ((int)(Math.random()* 500));
    int _radius = 30;
    NewPanel()
    {
        //setBackground(Color.BLUE);
        addMouseListener(new MouseListener() {
            @Override
            public void mouseClicked(MouseEvent mouseEvent)
            {
                if(insideCircle(mouseEvent.getX(), mouseEvent.getY()))
                {
                    _xPoint = ((int)(Math.random()* 500));
                    _yPoint = ((int)(Math.random()* 500));
                    repaint();
                }
                if(insideCircle1(mouseEvent.getX(), mouseEvent.getY()))
                {
                    _xPoint1 = ((int)(Math.random()* 500));
                    _yPoint1 = ((int)(Math.random()* 500));
                    repaint();
                }
            }
            @Override
            public void mousePressed(MouseEvent mouseEvent)
            {
                //To change body of implemented methods use File | Settings | File Templates.
            }
            @Override
            public void mouseReleased(MouseEvent mouseEvent)
            {
                //To change body of implemented methods use File | Settings | File Templates.
            }
            @Override
            public void mouseEntered(MouseEvent mouseEvent)
            {
                //To change body of implemented methods use File | Settings | File Templates.
            }
            @Override
            public void mouseExited(MouseEvent mouseEvent)
            {
                //To change body of implemented methods use File | Settings | File Templates.
            }
        });
    }
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        g.setColor(getRandomColor());
        g.fillOval(_xPoint - _radius, _yPoint - _radius,  _radius,  _radius);

        g.setColor(getRandomColor());
        g.fillOval(_xPoint1 - _radius, _yPoint1 - _radius, _radius, _radius);

    }
    public boolean insideCircle(int px,int py)
    {
        return distance(px, py, _xPoint, _yPoint) < _radius;
    }
    public double distance(double x1, double y1, double x2, double y2)
    {
        return Math.sqrt((x2 - x1) * (x2 -x1) + (y2 - y1) * (y2 - y1));
    }
    public boolean insideCircle1(int px,int py)
    {
        return distance1(px, py, _xPoint, _yPoint) < _radius;
    }
    public double distance1(double x1, double y1, double x2, double y2)
    {
        return Math.sqrt((x2 -x1) * (x2 -x1) + (y2 - y1) * (y2 - y1));
    }
    public Color getRandomColor()
    {
        Random numGen = new Random();
        return new Color(numGen.nextInt(256), numGen.nextInt(256), numGen.nextInt(256));
    }
}

[JosAH]

Your insideCircle( ... ) and insideCircle1( ... ) methods aren't correct.

kind regards,

Jos