How to capture mouse cursor in Java?

问题:

Ok, Most of you will think it's a duplicate because it's already written everywhere that it's not really doable and the only option is to do a screenshot using awt robot.

But... The issue is that the mouse cursor does not even appear in the picture produced by AWT robot... I tries gnome-screeshots and there I can see the mouse cursor. But from the java screenshot, nothing. The entire picture, but not mouse cursor. It's like it's hidding it before taking the picture. I search for a parameter like setIncludeMouseCursor or anything like that with no luck.

I can capture the mouse location, that's fine. But if I capture just this area, again no cursor.

Any idea how to enforce robot.createScreenCapture to capture also the mouse cursor?

回答1:

You need to use MouseInfo class and use its method static getPointerInfo() to get a Pointer object to represent the position of your cursor on the screen.

Once you have the position, you can use Robot to take a screenshot as a BufferedImage and draw the cursor on it. Simple !

SSCCE

package stack;

import java.awt.AWTException;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.MouseInfo;
import java.awt.PointerInfo;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.ImageIO;

public class GetMousePointer {
    public static void main(String[] args) {
        final String USER_HOME = System.getProperty("user.home");

        GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
        int width = gd.getDisplayMode().getWidth();
        int height = gd.getDisplayMode().getHeight();

        BufferedImage blackSquare = new BufferedImage(50, 50, BufferedImage.TYPE_3BYTE_BGR);
        for(int i = 0; i < blackSquare.getHeight(); i++){
            for(int j = 0; j < blackSquare.getWidth(); j++){
                blackSquare.setRGB(j, i, 128);
            }
        }


        try {
            Robot robot = new Robot();
            BufferedImage screenshot = robot.createScreenCapture(new Rectangle(0,0,width,height));
            PointerInfo pointer = MouseInfo.getPointerInfo();
            int x = (int) pointer.getLocation().getX();
            int y = (int) pointer.getLocation().getY();

            screenshot.getGraphics().drawImage(blackSquare, x, y, null);
            ImageIO.write(screenshot, "PNG", new File(USER_HOME, "screenshot.PNG"));

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}  

Output

The top-left corner of the blue square is the position of my cursor.

回答2:

You can extend Robot and override createScreenCapture to (given the cursor position) draw in the capture a cursor.

Something like this:

@Override
public BufferedImage createScreenCapture(){
    BufferedImage img = Super.createScreenCapture();
    return drawCursor(x,y,img); 
}

Obvioulsy drawCursor returns a BufferedImage.