ImageBrightener

This program loads an image when the program starts. Everytime that the user clicks the mouse, the image gets brighter.

import java.awt.*;
import objectdraw.*;

/**
 * This program reads an image from a file.  When the user
 * clicks the button, the image is brightened.
 * 
 * @author Barbara Lerner
 * @version March 26, 2008
 */
public class ImageBrightener extends FrameWindowController
{
    // The number of columns of pixels in the image
    private int imgWidth;
    
    // The number of rows of pixels in the image
    private int imgHeight;
    
    // The picture as read from the file
    private Picture picture;
    
    // The image as displayed on the screen
    private VisibleImage visibleImage;
    
    // The name of the file containing the picture
    private static final String FILENAME = "http://www.mtholyoke.edu/~blerner/cs101/Examples/Lecture16/ImageBrightener/KidsAndEleanor.jpg";
    
    /** 
     * Load the picture from the file and display it
     */
    public void begin() {
        resize (488, 686);

        picture = new Picture (FILENAME);
        imgWidth = picture.getWidth();
        imgHeight = picture.getHeight();
        showImage();
    }
    
    /**
     * Removes the existing image if there is one.  Then displays the picture
     * including any brightening that has been done so far
     */
    private void showImage () {
        if (visibleImage != null) {
            visibleImage.removeFromCanvas();
        }
        visibleImage = picture.createVisibleImage (0, 0, canvas);
    }
    
    /**
     * When the user clicks the mouse, brighten the picture and redisplay it.
     */
    public void onMouseClick (Location point) {
        brighten();
        showImage();
    }
            
    /**
     * Visit each pixel in the image and replace the current color of the pixel
     * with a brighter color.
     */
    private void brighten () {
        for (int row = 0; row < imgHeight; row++) {
            for (int col = 0; col < imgWidth; col++) {
                picture.setPixel (row, col, picture.getPixel(row, col).brighter());
            }
        }
   }
}