随笔档案(496)

/* 主要使用的是java.util.Robot类来捕获屏幕,
* 可以实现对屏幕一个矩形区域的捕获,通过这个类,
* 我们也可以实现一个远程桌面控制的程序
*/

package com.qiu.util;
import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.imageio.*;
import java.io.*;

public class ScreenCapture {
//test main
public static void main(String[] args) throws Exception{
   String userdir = System.getProperty("user.dir");
   File tempFile = new File("d:","temp.png");
   ScreenCapture capture = ScreenCapture.getInstance();
   capture.captureImage();  
   JFrame frame = new JFrame();
   JPanel panel = new JPanel();
   panel.setLayout(new BorderLayout());
   JLabel imagebox = new JLabel();
   panel.add(BorderLayout.CENTER,imagebox);  
   imagebox.setIcon(capture.getPickedIcon());
   capture.saveToFile(tempFile);
   capture.captureImage();
   imagebox.setIcon(capture.getPickedIcon());
   frame.setContentPane(panel);
   frame.setSize(400,300);
   frame.show();
   System.out.println("Over");
}

private ScreenCapture() {
  
   try{
    robot = new Robot();
   }
   catch(AWTException e) {
    System.err.println("Internal Error: " + e);
    e.printStackTrace();
   }  
   JPanel cp = (JPanel)dialog.getContentPane();
   cp.setLayout(new BorderLayout());  
   labFullScreenImage.addMouseListener(new MouseAdapter() {
     public void mouseReleased(MouseEvent evn) {
       isFirstPoint = true;
       pickedImage = fullScreenImage.getSubimage(recX,recY,recW,recH);
       dialog.setVisible(false);     
     }
    });
   
   labFullScreenImage.addMouseMotionListener(new MouseMotionAdapter() {
     public void mouseDragged(MouseEvent evn) {
      if(isFirstPoint) {
       x1 = evn.getX();
       y1 = evn.getY();
       isFirstPoint = false;  
      }
      else {
       x2 = evn.getX();
       y2 = evn.getY();
       int maxX = Math.max(x1,x2);
       int maxY = Math.max(y1,y2);
       int minX = Math.min(x1,x2);
       int minY = Math.min(y1,y2);
       recX = minX;
       recY = minY;
       recW = maxX-minX;
       recH = maxY-minY;
       labFullScreenImage.drawRectangle(recX,recY,recW,recH);    
      }
     }
    
     public void mouseMoved(MouseEvent e) {
      labFullScreenImage.drawCross(e.getX(),e.getY());
     }
    });
   
   cp.add(BorderLayout.CENTER,labFullScreenImage);
   dialog.setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
   dialog.setAlwaysOnTop(true);
   dialog.setMaximumSize(
    Toolkit.getDefaultToolkit().getScreenSize());
   dialog.setUndecorated(true);
   dialog.setSize(dialog.getMaximumSize());
   dialog.setModal(true);
}
//Singleton Pattern
public static ScreenCapture getInstance() {
   return defaultCapturer;
}
/**捕捉全屏慕*/
public Icon captureFullScreen() {
   fullScreenImage = robot.createScreenCapture(new Rectangle(
    Toolkit.getDefaultToolkit().getScreenSize()));
   ImageIcon icon = new ImageIcon(fullScreenImage);
   return icon;
}
/**捕捉屏幕的一个矫形区域
   */
public void captureImage() {
   fullScreenImage = robot.createScreenCapture(new Rectangle(
    Toolkit.getDefaultToolkit().getScreenSize()));
   ImageIcon icon = new ImageIcon(fullScreenImage);
   labFullScreenImage.setIcon(icon);  
   dialog.setVisible(true);
}
/**得到捕捉后的BufferedImage*/
public BufferedImage getPickedImage() {
   return pickedImage;
}
/**得到捕捉后的Icon*/
public ImageIcon getPickedIcon() {
   return new ImageIcon(getPickedImage());
}
/**储存为一个文件,为PNG格式
  *@deprecated
   *replaced by saveAsPNG(File file)
   **/
@Deprecated
public void saveToFile(File file) throws IOException{
   ImageIO.write(getPickedImage(),defaultImageFormater,file);
}
/**储存为一个文件,为PNG格式*/
public void saveAsPNG(File file) throws IOException {
   ImageIO.write(getPickedImage(),"png",file);
}
/**储存为一个JPEG格式图像文件*/
public void saveAsJPEG(File file) throws IOException {
   ImageIO.write(getPickedImage(),"JPEG",file);
}

/**写入一个OutputStream*/
public void write(OutputStream out) throws IOException{
   ImageIO.write(getPickedImage(),defaultImageFormater,out);
}

//singleton design pattern
private static ScreenCapture defaultCapturer = new ScreenCapture();
private int x1,y1,x2,y2;
private int recX,recY,recH,recW; //截取的图像
private boolean isFirstPoint   = true;
private BackgroundImage labFullScreenImage = new BackgroundImage();
private Robot robot;
private BufferedImage fullScreenImage;
private BufferedImage pickedImage;
private String defaultImageFormater = "png";
private JDialog dialog = new JDialog();
}

/**显示图片的Label*/
class BackgroundImage extends JLabel{
public void paintComponent(Graphics g) {
   super.paintComponent(g);
   g.drawRect(x,y,w,h);
   String area = Integer.toString(w)+" * "+ Integer.toString(h);
   g.drawString(area,x+(int)w/2-15,y+(int)h/2);
   g.drawLine(lineX,0,lineX,getHeight());
   g.drawLine(0,lineY,getWidth(),lineY);
}

public void drawRectangle(int x,int y,int width,int height) {
   this.x = x;
   this.y = y;
   h = height;
   w = width;
   repaint();
}

public void drawCross(int x,int y) {
   lineX = x;
   lineY = y;
   repaint();
}

int lineX,lineY;
int x,y,h,w;
}