Coordinates of a JTextPane to make a Screenshot in Java

Question

I hope some one can help me, this is what I want to do.

I have a JTextPane and I want to take a screenshot to that specific JTextPane coordinates and size, so far I can do a screenshot with the size of the JTextPane but I can't get the specific coordinates my screenshots always gets the (0,0) coordinates.

This is my method:

void capturaPantalla () 
{
    try
    {
        int x = txtCodigo.getX();
        int y = txtCodigo.getY();

        Rectangle areaCaptura = new Rectangle(x, y, txtCodigo.getWidth(), txtCodigo.getHeight());

        BufferedImage capturaPantalla = new Robot().createScreenCapture(areaCaptura);

        File ruta = new File("P:\\captura.png");

        ImageIO.write(capturaPantalla, "png", ruta);

        JOptionPane.showMessageDialog(null, "Codigo de barras guardado!");      
    }

    catch (IOException ioe) 
    {
        System.out.println(ioe);
    }     

    catch(AWTException ex)
    {
        System.out.println(ex);
    }
} 

Answer 1

When you call getX() and getY() on any Swing component, you get the x and y relative to the component's container, not the screen. Instead you want the location of the component relative to the screen and get position based on that via getLocationOnScreen()

Point p = txtCodigo.getLocationOnScreen();
int x = p.x;
int y = p.y;

As per MadProgrammer's comment, you could simply call printAll(Graphics g) on your txtCodigo component, passing in a Graphics object obtained from a properly sized BufferedImage and forgo use of a Robot.

Dimension d = txtCodigo.getSize();
BufferedImage img = new BufferedImage(d.width, d.height, BufferedImage.TYPE_INT_ARGB);
Graphics g = img.getGraphics();
txtCodigo.printAll(g);
g.dispose();
// use ImageIO to write BufferedImage to file

---

To compare to the two methods:

import java.awt.AWTException;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import java.util.Random;

import javax.swing.*;

@SuppressWarnings("serial")
public class RobotVsPrintAll extends JPanel {
   private static final int WORDS = 400;
   private JTextArea textArea = new JTextArea(20, 40);
   private JScrollPane scrollPane = new JScrollPane(textArea);
   private Random random = new Random();

   public RobotVsPrintAll() {
      StringBuilder sb = new StringBuilder();
      for (int i = 0; i < WORDS; i++) {
         int wordLength = random.nextInt(4) + 4;
         for (int j = 0; j < wordLength; j++) {
            char myChar = (char) (random.nextInt('z' - 'a' + 1) + 'a');
            sb.append(myChar);
         }
         sb.append(" ");
      }
      textArea.setText(sb.toString());

      textArea.setLineWrap(true);
      textArea.setWrapStyleWord(true);
      scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

      JButton robot1Btn = new JButton(new Robot1Action("Robot 1"));
      JButton robot2Btn = new JButton(new Robot2Action("Robot 2"));
      JButton printAllBtn = new JButton(new PrintAllAction("Print All"));

      JPanel btnPanel = new JPanel();
      btnPanel.add(robot1Btn);
      btnPanel.add(robot2Btn);
      btnPanel.add(printAllBtn);

      setLayout(new BorderLayout());
      add(scrollPane, BorderLayout.CENTER);
      add(btnPanel, BorderLayout.PAGE_END);
   }

   private void displayImg(BufferedImage img) {
      ImageIcon icon = new ImageIcon(img);
      JOptionPane.showMessageDialog(this, icon, "Display Image", 
            JOptionPane.PLAIN_MESSAGE);
   }

   private class Robot1Action extends AbstractAction {
      public Robot1Action(String name) {
         super(name);
         int mnemonic = (int) name.charAt(0);
         putValue(MNEMONIC_KEY, mnemonic);
      }

      @Override
      public void actionPerformed(ActionEvent e) {
         try {
            Component comp = scrollPane.getViewport();
            Point p = comp.getLocationOnScreen();
            Dimension d = comp.getSize();

            Robot robot = new Robot();

            Rectangle screenRect = new Rectangle(p.x, p.y, d.width, d.height);
            BufferedImage img = robot.createScreenCapture(screenRect);
            displayImg(img);

         } catch (AWTException e1) {
            e1.printStackTrace();
         }

      }

   }

   private class Robot2Action extends AbstractAction {
      public Robot2Action(String name) {
         super(name);
         int mnemonic = (int) name.charAt(0);
         putValue(MNEMONIC_KEY, mnemonic);
      }

      @Override
      public void actionPerformed(ActionEvent e) {
         try {
            Component comp = textArea;
            Point p = comp.getLocationOnScreen();
            Dimension d = comp.getSize();

            Robot robot = new Robot();

            Rectangle screenRect = new Rectangle(p.x, p.y, d.width, d.height);
            BufferedImage img = robot.createScreenCapture(screenRect);
            displayImg(img);

         } catch (AWTException e1) {
            e1.printStackTrace();
         }

      }

   }

   private class PrintAllAction extends AbstractAction {
      public PrintAllAction(String name) {
         super(name);
         int mnemonic = (int) name.charAt(0);
         putValue(MNEMONIC_KEY, mnemonic);
      }

      public void actionPerformed(ActionEvent e) {
         Dimension d = textArea.getSize();
         BufferedImage img = new BufferedImage(d.width, d.height, BufferedImage.TYPE_INT_ARGB);
         Graphics g = img.getGraphics();
         textArea.printAll(g);
         g.dispose();
         displayImg(img);
      }
   }

   private static void createAndShowGui() {
      RobotVsPrintAll mainPanel = new RobotVsPrintAll();

      JFrame frame = new JFrame("Robot Vs PrintAll");
      frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

If you print the text component with printAll, you get the entire text component, even the parts that are not displayed in the JScrollPane's viewport.

Answer 2

You can use the Screen Image class which does all the work for you. All you do is specify the component you want to capture.

The code would be:

BufferedImage bi = ScreenImage.createImage( component );

And you can save the image to a file using:

ScreenImage.writeImage(bi, "imageName.jpg");

This class will use the painting method of the Swing component which is more efficient than using a Robot.