// purpose: take snapshots of images

import java.io.*;
import java.awt.*;
import java.awt.image.*;
import javax.swing.*;
import javax.imageio.*;

public class Capturer {

    public static final String DEFAULT_FILENAME = "cs1112-draw.jpg";

    // method takeSnapshot(): saves a snapshot of the image to default file
    public static void takeSnapshot( BufferedImage image ) {
        Capturer.takeSnapshot( image, DEFAULT_FILENAME );
    }

    // method takeSnapshot(): saves a snapshot of the image to filename
    public static void takeSnapshot( BufferedImage image, String filename ) {
        try {
            File f = new File( filename );
            ImageIO.write( image, "jpg", f );
        }
        catch ( Exception e ) {
            System.out.println( "Unable to capture image and save to " 
                       + filename );
        }
    }

    // method takeSnapshot(): takes a snapshot of the pane and calls it filename
    public static void takeSnapshot( Container pane, String filename ) {
       // determine region on desktop showing the drawing
        Point origin = new Point();
        SwingUtilities.convertPointToScreen( origin, pane );
        Rectangle region = new Rectangle( origin, pane.getSize() );

        // capture region as an image
        try {
            BufferedImage image = new Robot().createScreenCapture( region );

            // save image to file
            File f = new File( filename );
            ImageIO.write( image, "jpg", f );
        }
        catch ( Exception e ) {
            System.out.println( "Unable to capture image and save to " 
                       + filename );
        }
    }

    // method takeSnapshot(): takes a snapshot of the pane to default file
    public static void takeSnapshot( Container pane ) {
        Capturer.takeSnapshot( pane, DEFAULT_FILENAME );
    }
}