JFrame Glasspane 也在 JDialog 之上，但不应该

Looking at you source code, you only ever register the frame's glass pane to the AWTListener. Now, on the surface, this doesn't seem like a bad thing. The AWTListener will be notified of ALL the mouse events in the system, but the instance of GlassPane that is actually receiving the events will only know about the frame...

基本上，这意味着 dialogGlas 永远不会收到任何事件，因为它没有注册.

Basically, this means that the dialogGlas will never receive any events, as it's not registered.

首先，您需要将 frameGlas 和 dialogGlas 都注册为侦听器.

First, you need to register both the frameGlas and dialogGlas as listeners.

其次，您不应该试图猜测"目标.MouseEvent(实际上是所有事件)都有一个来源.您应该将源代码与 target 进行比较，以便仅当事件发生在您感兴趣的组件上时才能对事件做出反应......

Second, you shouldn't be trying to "guess" the target. MouseEvent (in fact all events) have a source. You should be comparing the source with the target so you can react to events only when they occur on components you're interested in...

import java.awt.AWTEvent;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.AWTEventListener;
import java.awt.event.MouseEvent;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Main {

    static JFrame frame;
    static JDialog dialog;

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

    public Main() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }


                frame = new JFrame();
                frame.setSize(600, 600);
                GlassPane frameGlas = new GlassPane(frame);
                frame.setGlassPane(frameGlas);
                frame.setVisible(true);

                frameGlas.setVisible(true);
                dialog = new JDialog(frame);

                dialog.setSize(100, 100);
                GlassPane dialogGlas = new GlassPane(dialog);
                dialog.setGlassPane(dialogGlas);
                dialogGlas.setVisible(true);
                dialog.setVisible(true);

                // Register a listener for the frameGlas
                Toolkit.getDefaultToolkit().addAWTEventListener(
                        frameGlas,
                        AWTEvent.MOUSE_MOTION_EVENT_MASK
                        | AWTEvent.MOUSE_EVENT_MASK);
                // Register a listener for the dialogGlas
                Toolkit.getDefaultToolkit().addAWTEventListener(
                        dialogGlas,
                        AWTEvent.MOUSE_MOTION_EVENT_MASK
                        | AWTEvent.MOUSE_EVENT_MASK);
            }
        });
    }

    public class GlassPane extends JPanel implements AWTEventListener {

        private static final long serialVersionUID = 5110857185182004819L;
        private final Window target;

        public GlassPane(Window target) {
            super(null);
            this.target = target;

        }

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

                MouseEvent originalEvent = (MouseEvent) event;

                MouseEvent e = originalEvent;
                Component source = e.getComponent();
                System.out.println("Source: " + source);
                System.out.println("Target: " + target);
                if (target != null && target.equals(source)) {
                    e = SwingUtilities.convertMouseEvent(
                            ((MouseEvent) event).getComponent(),
                            (MouseEvent) event, this);

                    if (e.getID() == MouseEvent.MOUSE_PRESSED) {

                        Point p = target.getLocationOnScreen();
                        System.out.println(p.getX());
                    }
                }
            }
        }
    }
}

现在，在我的脑海中，MouseListener 的问题是它们是贪婪的，它们阻止事件级联超出它们注册的组件.

Now, off the top of my head, the problem you're having with MouseListener is that they are greedy, they prevent the events from cascading beyond the component they are registered on.

这篇关于JFrame Glasspane 也在 JDialog 之上，但不应该的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！