Java拖放和鼠标监听器

Question

我在触摸界面上使用以下逻辑，因此我希望能够使用mousePressed发起拖动，但同时如果用户不拖动，则可以使用mouseClicked或mouseReleased。

在mousePressed上，我有一个拖动正在启动。 在mouseClicked上，我希望它打印出“ mouseClicked”，并在“ mouseReleased”上打印mouseReleased，但是由于某种原因

    dropLabel.getTransferHandler().exportAsDrag(dropLabel, e,
            TransferHandler.COPY);

吞下事件导致mouseClicked和mouseReleased事件即使我不移动鼠标也不会被触发。 请注意，注释掉该行会导致所有侦听器被触发（但显然不会启动拖动）。

如何在用户不进行任何拖动的情况下使所有鼠标事件按我想要的方式发生，特别是mouseClicked / mouseReleased，而如果用户进行拖动则仍然能够exportAsDragged？ 欢迎任何破解/破解/反思解决方案。

这是我正在使用的一些示例代码，它说明了我的实际问题：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.TransferHandler;

public class DragTest extends JFrame implements MouseMotionListener,
        MouseListener {

    private JPanel leftPanel = new JPanel(null);
    private JPanel rightPanel = new JPanel(null);
    JLabel dropLabel;

    public DragTest() {
        this.setLayout(new GridLayout(1, 2));

        leftPanel.setBorder(BorderFactory.createLineBorder(Color.black));
        rightPanel.setBorder(BorderFactory.createLineBorder(Color.black));
        this.add(leftPanel);
        this.add(rightPanel);
        leftPanel.addMouseListener(this);
        leftPanel.addMouseMotionListener(this);

        JTextArea area = new JTextArea();

        rightPanel.setLayout(new GridLayout(1, 1));
        rightPanel.add(area);

        dropLabel = new JLabel("drop");
        dropLabel.setTransferHandler(new TransferHandler("text"));

    }

    @Override
    public void mousePressed(MouseEvent e) {
        System.out.println("mousePressed");


        Dimension labelSize = dropLabel.getPreferredSize();
        dropLabel.setSize(labelSize);
        int x = e.getX() - labelSize.width / 2;
        int y = e.getY() - labelSize.height / 2;
        dropLabel.setLocation(x, y);
        leftPanel.add(dropLabel);


        dropLabel.getTransferHandler().exportAsDrag(dropLabel, e,
                TransferHandler.COPY);

        repaint();

    }

    @Override
    public void mouseDragged(MouseEvent me) {
        System.out.println("mouseDragged");
    }

    @Override
    public void mouseMoved(MouseEvent e) {

    }

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

    @Override
    public void mouseReleased(MouseEvent e) {

        System.out.println("mouseReleased");

    }

    @Override
    public void mouseEntered(MouseEvent e) {

    }

    @Override
    public void mouseExited(MouseEvent e) {

    }

    public static void main(String[] args) {

        DragTest frame = new DragTest();
        frame.setVisible(true);
        frame.setSize(600, 400);
        frame.setResizable(false);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

Answer 1

你真的需要鼠标释放火还是什么？ 我认为这应该运作良好：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.TransferHandler;

public class DragTest extends JFrame implements MouseMotionListener,
        MouseListener {

    private JPanel leftPanel = new JPanel(null);
    private JPanel rightPanel = new JPanel(null);
    JLabel dropLabel;

    public DragTest() {
        this.setLayout(new GridLayout(1, 2));

        leftPanel.setBorder(BorderFactory.createLineBorder(Color.black));
        rightPanel.setBorder(BorderFactory.createLineBorder(Color.black));
        this.add(leftPanel);
        this.add(rightPanel);
        leftPanel.addMouseListener(this);
        leftPanel.addMouseMotionListener(this);

        JTextArea area = new JTextArea();

        rightPanel.setLayout(new GridLayout(1, 1));
        rightPanel.add(area);

        dropLabel = new JLabel("drop");
        dropLabel.setTransferHandler(new TransferHandler("text"));

    }
    @Override
    public void mousePressed(MouseEvent e) {
        System.out.println("mousePressed");
        Dimension labelSize = dropLabel.getPreferredSize();
        dropLabel.setSize(labelSize);
        int x = e.getX() - labelSize.width / 2;
        int y = e.getY() - labelSize.height / 2;
        dropLabel.setLocation(x, y);
        leftPanel.add(dropLabel);



        repaint();

    }

    @Override
    public void mouseDragged(MouseEvent me) {
        System.out.println("mouseDragged");
            dropLabel.getTransferHandler().exportAsDrag(dropLabel, me,
                    TransferHandler.COPY);
    }

    @Override
    public void mouseMoved(MouseEvent e) {
    }

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

    @Override
    public void mouseReleased(MouseEvent e) {
        System.out.println("mouseReleased");

    }

    @Override
    public void mouseEntered(MouseEvent e) {

    }

    @Override
    public void mouseExited(MouseEvent e) {

    }

    public static void main(String[] args) {

        DragTest frame = new DragTest();
        frame.setVisible(true);
        frame.setSize(600, 400);
        frame.setResizable(false);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

我刚刚调用了调用来将drag事件启动到mouseDragged调用中，这样如果你只是单击鼠标然后一切正常调用。 但是，如果您拖动鼠标，它将触发拖放调用，这仍会阻止其他调用，但仅在您拖动时再次执行。 如果你只是点击，它就会正常发射。