Swing newbie, want to make a small moving eye Java GUI practice, but stuck

Question

I want to implement a panel that draws two eyes that move to look up, in the center or down, depending on whether the mouse cursor is above, inside or under the eyes. I first used this code to make eyes:

public class EyesPanel extends JPanel implements ActionListener {
    // images
    public void paintComponent(Graphics g) {
        super.paintComponents(g);
        g.drawOval(130, 100, 120, 120);
        g.drawOval(250, 100, 120, 120);
        g.fillOval(175, y, 30, 30);   // x: 175  y: 145
        g.fillOval(295, y, 30, 30);   // x: 295  y: 145
    }

And then it's time to add an event listener for this class to work, but here is the part that I'm stuck with. I know how to do graphics moving (ActionListener), and I know how to implement MouseInputListener (extends MouseInputListener). However, combining the two together, I feel upset. Can someone tell me how to do this, give me sample code can be very helpful.

Below is my code, not a valid and complete code:

public class EyesPanel extends JPanel implements ActionListener {
    private JPanel panel;
    private int y;
    private int dy;
    private Timer t;
    private Mouse move;

    public EyesPanel() {
        dy = 5;
        y = 145;

        // mouse detector
        this.addMouseListener(new Mouse());
        this.addMouseMotionListener(new Mouse());

        // Timer 
        t = new Timer(100, this);
    }

    // images
    public void paintComponent(Graphics g) {
        super.paintComponents(g);
        g.drawOval(130, 100, 120, 120);
        g.drawOval(250, 100, 120, 120);
        g.fillOval(175, y, 30, 30);   // x: 175  y: 145
        g.fillOval(295, y, 30, 30);   // x: 295  y: 145
    }

    public void actionPerformed(ActionEvent event) {
        moveDown();     //➜ not complete, don't know how to implement
    }

    // move up
    private void moveUp() {
        if (move.move() == 1) {
            t.start();
            y = y + dy;
            repaint();
        } else {
            t.stop();
        }
    }

    // move down
    private void moveDown() {
        if (move.move() == -1) {
            t.start();
            y = y - dy;
            repaint();
        } else {
            t.stop();
        }
    }
    // ➜ not complete, trying, but no clue
}

My mouse event class:

public class Mouse extends MouseInputAdapter {
    private int y;

    public void mouseEntered(MouseEvent event) {
        JPanel pane =  (JPanel) event.getSource();
        y = pane.getHeight();      // ➜ not complete
    }
}

Answer 1

, gota s off super.paintComponents(g);

    import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;

import java.awt.event.MouseMotionListener;
import java.util.Timer;

import javax.swing.JPanel;


public class EyesPanel extends JPanel implements ActionListener,MouseMotionListener{
    private JPanel panel;
    private int y;
    private int dy;
    private Timer t;


    public EyesPanel() {
        dy = 5;
        y = 145;

        // mouse detector
        this.addMouseMotionListener(this);


        // Timer 

    }

    // images
    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        g.drawOval(130, 100, 120, 120);
        g.drawOval(250, 100, 120, 120);
        g.fillOval(175, y, 30, 30);   // x: 175  y: 145
        g.fillOval(295, y, 30, 30);   // x: 295  y: 145
    }



    // move up

    // ➜ not complete, trying, but no clue




@Override
public void actionPerformed(ActionEvent arg0) {
    // TODO Auto-generated method stub

}

    @Override
    public void mouseDragged(MouseEvent arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void mouseMoved(MouseEvent arg0) {
        // TODO Auto-generated method stub
        System.out.println(arg0.getY());
        if(arg0.getY() > 101 && arg0.getY() < 187)
        y = arg0.getY();
        repaint();

    }


}

Answer 2

, , .

.

• Eye, .

• MovingEyes, JFrame DrawingPanel, DrawingPanel. Eye, 2 MovingEyes.

• paintComponent DrawingPanel , . . , , .

• EyeballListener . ( ) , . x y .

.

package com.ggl.testing;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class MovingEyes implements Runnable {

    private static final int drawingWidth = 400;
    private static final int drawingHeight = 400;
    private static final int eyeballHeight = 150;
    private static final int eyeballWidthMargin = 125;
    private static final int eyeballOuterRadius = 50;
    private static final int eyeballInnerRadius = 20;

    private DrawingPanel drawingPanel;

    private Eye[] eyes;

    private JFrame frame;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new MovingEyes());
    }

    public MovingEyes() {
        this.eyes = new Eye[2];
        this.eyes[0] = new Eye(new Point(eyeballWidthMargin, eyeballHeight));
        this.eyes[1] = new Eye(new Point(drawingWidth - eyeballWidthMargin,
                eyeballHeight));
    }

    @Override
    public void run() {
        frame = new JFrame("Moving Eyes");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        drawingPanel = new DrawingPanel();
        frame.add(drawingPanel);

        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public class DrawingPanel extends JPanel {

        private static final long serialVersionUID = -2977860217912678180L;

        public DrawingPanel() {
            this.addMouseMotionListener(new EyeballListener());
            this.setBackground(Color.WHITE);
            this.setPreferredSize(new Dimension(drawingWidth, drawingHeight));
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);

            g.setColor(Color.BLACK);

            for (Eye eye : eyes) {
                drawCircle(g, eye.getOrigin(), eyeballOuterRadius);
                fillCircle(g, eye.getEyeballOrigin(), eyeballInnerRadius);
            }
        }

        private void drawCircle(Graphics g, Point origin, int radius) {
            g.drawOval(origin.x - radius, origin.y - radius, radius + radius,
                    radius + radius);
        }

        private void fillCircle(Graphics g, Point origin, int radius) {
            g.fillOval(origin.x - radius, origin.y - radius, radius + radius,
                    radius + radius);
        }

    }

    public class Eye {
        private final Point origin;
        private Point eyeballOrigin;

        public Eye(Point origin) {
            this.origin = origin;
            this.eyeballOrigin = origin;
        }

        public Point getEyeballOrigin() {
            return eyeballOrigin;
        }

        public void setEyeballOrigin(Point eyeballOrigin) {
            this.eyeballOrigin = eyeballOrigin;
        }

        public Point getOrigin() {
            return origin;
        }

    }

    public class EyeballListener extends MouseMotionAdapter {

        private final double eyeballDistance = eyeballOuterRadius
                - eyeballInnerRadius - 5;

        @Override
        public void mouseMoved(MouseEvent event) {
            Point p = event.getPoint();
            for (Eye eye : eyes) {
                Point origin = eye.getOrigin();
                double theta = Math.atan2((double) (p.y - origin.y),
                        (double) (p.x - origin.x));
                int x = (int) Math.round(Math.cos(theta) * eyeballDistance)
                        + origin.x;
                int y = (int) Math.round(Math.sin(theta) * eyeballDistance)
                        + origin.y;
                eye.setEyeballOrigin(new Point(x, y));
            }

            drawingPanel.repaint();
        }

    }

}

Answer 3

You are looking for a method mouseMovedinstead mouseEntered.