Java Swing 通过拖动鼠标滚动

Question

我正在尝试创建一个手动滚动器，当您在 JPanel 上拖动鼠标时，它会滚动。到目前为止我还无法改变观点。这是我的代码:

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;


public class HandScroller extends JFrame {

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

    public HandScroller() {
        setDefaultCloseOperation(EXIT_ON_CLOSE);


        final JPanel background = new JPanel();
        background.add(new JLabel("Hand"));
        background.add(new JLabel("Scroller"));
        background.add(new JLabel("Test"));
        background.add(new JLabel("Click"));
        background.add(new JLabel("To"));
        background.add(new JLabel("Scroll"));

        final JScrollPane scrollPane = new JScrollPane(background);

        MouseAdapter mouseAdapter = new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                JViewport viewPort = scrollPane.getViewport();
                Point vpp = viewPort.getViewPosition();
                vpp.translate(10, 10);
                background.scrollRectToVisible(new Rectangle(vpp, viewPort.getSize()));
            }
        };

        scrollPane.getViewport().addMouseListener(mouseAdapter);
        scrollPane.getViewport().addMouseMotionListener(mouseAdapter);

        setContentPane(scrollPane);
        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }

}

我认为这会将 View 在 x 和 y 方向上移动 10，但它根本没有做任何事情。还有什么我应该做的吗？

谢谢。

Answer 1

我认为您可以使用此代码向各个方向移动 View

public void mouseDragged(MouseEvent e) {

           JViewport viewPort = scroll.getViewport();
           Point vpp = viewPort.getViewPosition();
           vpp.translate(mouseStartX-e.getX(), mouseStartY-e.getY());
           scrollRectToVisible(new Rectangle(vpp, viewPort.getSize()));

}

public void mousePressed(MouseEvent e) {

    mouseStartX = e.getX();
    mouseStartY = e.getY();

}