java - mouse motion listener only in one direction

Question

i have been working on mouse motion listener in Java couldn't sort it out completely because i want the object to move towards the direction where ever on the screen the mouse is pointed at but unforunately when the mouse is inside the applet window, the object moves only towards a single direction. Here is my code below..

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

public class MouseOver extends Applet implements KeyListener, MouseListener,
      MouseMotionListener {
   private int[] Xpoints = { 0, -5, 5 };
   private int[] Ypoints = { -10, -2, -2 };
   private double xpos, ypos;
   private Polygon poly;
   int polyrot = 0;
   private int width; // !! added
   private int height; // !! added

   public void init() {
      poly = new Polygon(Xpoints, Ypoints, Xpoints.length);
      addKeyListener(this);
      addMouseListener(this);
      addMouseMotionListener(this);
   }

   public void paint(Graphics g) {
      Graphics2D g2d = (Graphics2D) g;
      AffineTransform id = new AffineTransform();
      width = getSize().width;
      height = getSize().height;
      g2d.setColor(Color.BLACK);
      g2d.fillRect(0, 0, width, height);
      g2d.setColor(Color.RED);
      g2d.draw(poly);
      g2d.translate(width / 2, height / 2);
      g2d.rotate(Math.toRadians(polyrot));
      g2d.scale(5, 5);
   }

   public void keyReleased(KeyEvent k) {
   }

   public void keyTyped(KeyEvent k) {
   }

   public void keyPressed(KeyEvent k) {
      switch (k.getKeyCode()) {
      case KeyEvent.VK_LEFT:
         if (polyrot < 0) {
            polyrot = 359;
            polyrot++;
         }
         repaint();
         break;
      case KeyEvent.VK_RIGHT:
         if (polyrot > 360) {
            polyrot = 0;
            polyrot--;
         }
         repaint();
         break;
      }
   }

   public void mouseEntered(MouseEvent m) {
   }

   public void mouseExited(MouseEvent m) {
   }

   public void mouseReleased(MouseEvent m) {
   }

   public void mouseClicked(MouseEvent m) {
   }

   public void mousePressed(MouseEvent m) {
      switch (m.getButton()) {
      case MouseEvent.BUTTON1:
         if (polyrot < 0) {
            polyrot = 359;
            polyrot--;
         }
         repaint();
         break;
      case MouseEvent.BUTTON2:
         if (polyrot > 360) {
            polyrot = 0;
            polyrot++;
         }
         repaint();
         break;
      }
   }

   public void mouseMoved(MouseEvent e) {
      xpos = getX();
      if (xpos < 0) {
         polyrot--;
      } else if (xpos > 0) {
         polyrot++;
      }
      repaint();
      // !! break; // Doesn't belong here
   }

   @Override
   public void mouseDragged(MouseEvent e) {
      // You forgot this method
   }
}

Answer 1

Your problem is with this line:

public void mouseMoved(MouseEvent e){
 xpos=getX(); // ******
 if(xpos<0){polyrot--;}
 else if(xpos>0){polyrot++;}
 repaint();
 break;
}

That returns the x position of the applet not the mouse cursor. You need to use your MouseEvent object, e and instead get the mouse's position. Change it to:

xpos = e.getX();

Please don't ignore the comment that I made to your question. Please remember that we're volunteers who help on our free time. Please don't make it any more difficult than it has to be to help you.

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I've tried to edit your code so that it compiles, and now is indented. Consider creating a Swing application, not an AWT application, since Swing apps are more flexible, powerful and robust.