How to get time between mouse moves?

问题:

I'm trying to get the millisecond time between times when the mouse moves. I'm using a library for the mouse move event so that it works globally. The problem is that with the code below the time is always zero.

        @Override
        public void mouseMoved(GlobalMouseEvent event)
        {
            //times the mouse has moved
            moveCount++;

            //if it's the first time moving mouse then it's the start time
            if (moveCount % 2 != 0)
            {
                startTime = System.currentTimeMillis();
            }

            //if it's the second time moving the mouse then it's the end 
            //time
            if (moveCount % 2 == 0)
            {
                long endTime = System.currentTimeMillis();
                long time = (endTime - startTime);

                System.out.println(time);
            }
        }

回答1:

If you want to detect a mouse movement and it's properties let's define the movement first:

A mouse movement can be defined as starting to move the mouse pointer from point A to point B and then the mouse pointer stay at point B for more than a threshold to detect it as the end of the movement.

If we define the problem like the above, we can solve it by starting a timer as the mouse starts to move and then restart that timer while the mouse is moving. Then if the timer timed out after a threshold we can assume that as an end to that movement started before. Then the time elapsed in which mouse pointer reached from point A to B is the time of that movement.

To code the above idea in a decent way we can define our MouseMovementListener, MouseMovementEvent and other utility classes in the following form:

Our custom event:

import java.awt.Point;

public class MouseMovementEvent {
    private Point startPoint;
    private Point endPoint;
    private Long  startNanoTime;
    private Long  endNanoTime;

    public MouseMovementEvent(Point startPoint, Point endPoint, Long startNanoTime, Long endNanoTime) {
        this.startPoint = startPoint;
        this.endPoint = endPoint;
        this.startNanoTime = startNanoTime;
        this.endNanoTime = endNanoTime;
    }

    public Point getStartPoint() {
        return startPoint;
    }
    public Point getEndPoint() {
        return endPoint;
    }
    public Long getStartNanoTime() {
        return startNanoTime;
    }
    public Long getEndNanoTime() {
        return endNanoTime;
    }       
    public Long getMotionDurationInNanos() {
        return endNanoTime - startNanoTime;
    }
}

The listener interface:

public interface MouseMovementListener {
    void movementOccured(MouseMovementEvent e);
}

Then the code to monitor mouse moves and translate it to Movement Event:

import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JComponent;
import javax.swing.Timer;

public class MouseMovementMonitor {

    private Point startPoint;
    private Point currentPoint;
    private Long  startTime;
    private Timer timer;

    public MouseMovementMonitor(JComponent componentToMonitor, int motionTimeDelay, final MouseMovementListener movementListener) {
        timer = new Timer(motionTimeDelay, new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                if(startPoint != null && !startPoint.equals(currentPoint)) {
                    movementListener.movementOccured(
                            new MouseMovementEvent(startPoint, currentPoint, startTime, System.nanoTime())
                        );
                }

                startPoint = null; // either can be 
                startTime  = null;

                // or reset process can be as follow instead of the two above lines: 
                // startPoint = currentPoint;
                // startTime  = System.nanoTime();

                timer.stop();
            }

        });

        componentToMonitor.addMouseMotionListener(new MouseMotionAdapter() {

            @Override
            public void mouseMoved(MouseEvent e) {
                if(startPoint == null) {
                    startPoint = e.getPoint();
                    startTime  = System.nanoTime();
                }
                currentPoint = e.getPoint();
                //
                if(timer.isRunning())
                    timer.restart();
                else
                    timer.start();
            }
        });
    }
}

And finally testing it:

import java.awt.BorderLayout;
import java.awt.Color;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;

public class Test {
    public static void main(String[] args) {
        JPanel p = new JPanel();
        p.setBackground(Color.PINK);

        new MouseMovementMonitor(p, 500, new MouseMovementListener() {
            @Override
            public void movementOccured(MouseMovementEvent e) {
                System.out.println("Movement Duration in nanos: " + e.getMotionDurationInNanos());              
            }
        });

        JFrame f = new JFrame();
        f.setBounds(200,200,200,200);
        f.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        f.setLayout(new BorderLayout());
        f.add(p, BorderLayout.CENTER);
        f.setVisible(true);
    }
}

In this example I didn't expose the start and end points of the movement but our MouseMovementEvent object has those information if you want them.

Hope this would be helpful!