Java检测长鼠标按键

问题描述：

如果用户按下JList组件超过3秒钟，是否有任何方法来捕获事件？

Is there any way to capture an event if a user press on JList component for more than 3 seconds?

我发现困难的部分是即使在用户放开鼠标左键之前，事件也需要触发。（可以通过几个mousePressed和mouseReleased轻松完成）

The difficult part i find is the event needs to be trigger even before the user let go of the mouse left button. (which can be easily done by couple mousePressed and mouseReleased)

答

您可以在mouseDown事件侦听器中设置一个计时器并执行它在初始延迟3000 ms后每500 ms。在您的鼠标中，您可以取消该定时器。在与计时器相关联的 TimerTask 对象的运行方法中，您可以执行所需任务的计算。这是我的解决方案提案：

You can set a timer in your mouseDown event listener and execute it every 500 ms after an initial delay of 3000 ms. In your mouseReleased you can cancel that timer. On the run method of the TimerTask object associated with your Timer you can perform the calculation of task you want. Here is my solution proposal:

import javax.swing.*;
import java.awt.event.*;
import java.util.*;

public class Test
{
    public static void main(String[] args)
    {
        final JFrame f = new JFrame();
        String[] data = {"one", "two", "three", "four"};
        JList myList = new JList(data);
        f.add(myList);
        myList.addMouseListener(
            new MouseAdapter()
            {
                private java.util.Timer t;
                public void mousePressed(MouseEvent e)
                {
                    if(t == null)
                    {
                        t = new java.util.Timer();
                    }
                    t.schedule(new TimerTask()
                    {
                        public void run()
                        {
                            System.out.println("My importan task goes here");
                        }
                    },3000,500);
                }

                public void mouseReleased(MouseEvent e)
                {
                    if(t != null)
                    {
                        t.cancel();
                        t = null;
                    }
                }
            }
            );
            f.pack();
            SwingUtilities.invokeLater(new Runnable()
            {
                public void run()
                {
                    f.setVisible(true);
                }
            }
        );
    }
}

Java检测长鼠标按键

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