Java中的鼠标坐标

Question

I'm working on getting the Co-ordinates of the mouse whenever I click on the window, everything is working perfect but I need to the text to appear where I click on the window, I don't want the text to be fixed in one place, I need it to appear wherever I click on the window. How can that be achieved?

Here is the Code:

 import java.awt.*;
 import javax.swing.JFrame;
 import javax.swing.JPanel;
 import javax.swing.JLabel;
 import java.awt.event.KeyAdapter;
 import java.awt.event.KeyEvent;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 public class mouseCrd extends JFrame {
 private JPanel contentPane;
 public mouseCrd() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 650, 650);
    setTitle("Mouse co-ordinates");
    setVisible(true);
    setResizable(false);
    contentPane = new JPanel();
    setContentPane(contentPane);
    contentPane.setLayout(null);
    JPanel panel = new JPanel();
    panel.setBounds(0, 0, 650, 650);
    contentPane.add(panel);
    JLabel label = new JLabel(".................");
    label.setFont(new Font("Tahoma", Font.BOLD, 30));
    panel.add(label);
    panel.addMouseListener(new MouseAdapter() {
        public void mouseClicked(MouseEvent e){
            label.setText("X = "+ e.getX()+" ; Y = "+e.getY());
        }
    });
    addKeyListener(new KeyAdapter() {
        @Override
        public void keyReleased(KeyEvent e) {
            super.keyReleased(e);
            int clr = e.getKeyChar();
            if(clr==KeyEvent.VK_B)
            {
                System.out.println("B is pressed");
                label.setForeground(Color.WHITE);
                panel.setBackground(Color.BLACK);
            }
            else if(clr==KeyEvent.VK_W)
            {
                System.out.println("W is pressed");
                label.setForeground(Color.BLACK);
                panel.setBackground(Color.WHITE);
            }
            else if(clr==KeyEvent.VK_R)
            {
                System.out.println("R is pressed");
                label.setForeground(Color.BLACK);
                panel.setBackground(Color.RED);
            }
            else if(clr==KeyEvent.VK_O)
            {
                System.out.println("O is pressed");
                label.setForeground(Color.BLACK);
                panel.setBackground(Color.ORANGE);
            }
            else if(clr==KeyEvent.VK_G)
            {
                System.out.println("G is pressed");
                label.setForeground(Color.BLACK);
                panel.setBackground(Color.GREEN);
            }
        }
    });
}
    public static void main(String[] args){
                EventQueue.invokeLater(new Runnable()
                {
                    public void run() {
                        try {
                            mouseCrd frame = new mouseCrd();
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                });
            }
        }

Answer 1

There's lots of ways you might achieve this, depending on your needs

For example, if you wanted to "overlay" the mouse coordinates onto of other components.

One issue with adding a MouseListener to a glassPane is it will block all the MouseEvent s from reaching the other components.

Instead, in this example, I tap directly into the Event Queue and process the events directly instead, this allows other components to continue monitoring mouse events through the use of MouseListener s

import java.awt.AWTEvent;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;

public class Test {

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

    public Test() {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                GlassPane glassPane = new GlassPane();
                frame.setGlassPane(glassPane);
                glassPane.setVisible(true);
                frame.add(new TestPane());
                frame.pack();
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setBorder(new EmptyBorder(20, 20, 20, 20));
            setLayout(new GridBagLayout());
            add(new JLabel("This is so you can keep doing stuff"));

            addMouseListener(new MouseAdapter() {
                @Override
                public void mouseClicked(MouseEvent e) {
                    System.out.println("...");
                }
            });
        }

    }

    public class GlassPane extends JPanel implements AWTEventListener {

        private static final long serialVersionUID = 5110857185182004819L;

        private JLabel mousePointLabel = new JLabel();

        public GlassPane() {
            super(null);
            Toolkit.getDefaultToolkit().addAWTEventListener(
                    this,
                    AWTEvent.MOUSE_MOTION_EVENT_MASK
                    | AWTEvent.MOUSE_EVENT_MASK);

            mousePointLabel.setForeground(Color.RED);
            add(mousePointLabel);
            setOpaque(false);
        }

        @Override
        public void eventDispatched(AWTEvent event) {
            if (event instanceof MouseEvent) {

                MouseEvent originalEvent = (MouseEvent) event;

                MouseEvent e = originalEvent;
                Component source = e.getComponent();
                e = SwingUtilities.convertMouseEvent(
                        ((MouseEvent) event).getComponent(),
                        (MouseEvent) event, this);

                if (e.getID() == MouseEvent.MOUSE_PRESSED) {
                    Point p = e.getPoint();
                    mousePointLabel.setText(p.getX() + "x" + p.getY());
                    Dimension size = mousePointLabel.getPreferredSize();
                    mousePointLabel.setSize(size);
                    mousePointLabel.setLocation(p.x - (size.width / 2), p.y - (size.height / 2));
                }
            }
        }
    }
}

Answer 2

According to some other answers out there , you will need to remove the Layout from the Panel where you want to move your component around in. Not considered good practice to remove the Layout, but it meets the requirements to place your component where you click.

Example:

import java.awt.Color;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;

public class ClickToMove
{
  public static void main(String[] args) {
    JFrame frame = new JFrame("Click To Move");
    frame.setSize(600, 400);
    
    JPanel panel = new JPanel();
    panel.setLayout(null);
    frame.getContentPane().add(panel);
    
    JLabel label = new JLabel("Click to move me!", SwingConstants.CENTER);
    label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
    label.setSize(150, 50);
    panel.add(label);
    
    panel.addMouseListener(new MouseAdapter() {
      @Override
      public void mouseReleased(MouseEvent event) {
        label.setLocation(event.getX(), event.getY());
        panel.repaint();
      }
    });
    
    frame.setVisible(true);
  }
}