Setting the fg/bg color of a 1 bit image

Question

Is there a simple way to set the foreground and background colors of a one bit image? What I need to do is draw a bitmap on a Canvas component where all black pixels in the loaded (gif) Image paint as my custom foreground color and all white pixels paint as my custom background color. I'm thinking maybe something like drawing a filled rectangle using the bitmap as a mask?? I am porting code from Windows, and this is something that is kind of built in to MFC.
Currently I have this working in Windows running Java 1.4.0, but it wont work on a Macintosh running Java 1.1 (or 1.2?). I'm wondering if I stumbled upon a quirk that only works in Windows?
This is the code from my Canvas object paint() method:
g.drawImage(bitmapUp, 0, 0, getForeground(), this);
g.setXORMode(getForeground());
g.drawImage(bitmapUp, 0, 0, getBackground(), this);
'bitmapUp' is a one color gif image with transparency. Basically anything that is not transparent gets filled with my foreground color. It seems like this is not the best way to go about things (even if it worked on all platforms).
Test it here if you want:
http://www.wizardmaster.com/test/muzakaster/
- Thanks, Markus P.Spanglestein

Answer 1

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.*;
import javax.swing.*;
public class TwoTone {
     static final int SIZE = 200;
     static BufferedImage image = new BufferedImage(SIZE,SIZE,
               BufferedImage.TYPE_BYTE_BINARY); //Black&White
     public static void main(String[] args) {
          JFrame f = new JFrame("TwoTone");
          f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          Graphics2D g2 = image.createGraphics();
          g2.setPaint(Color.WHITE);
          g2.setStroke(new BasicStroke(6f));
          g2.draw(new Ellipse2D.Float(0,0,SIZE, SIZE));
          g2.dispose();
          final JLabel label = new JLabel(new ImageIcon(image));
          label.addMouseListener(new MouseAdapter(){
               public void mousePressed(MouseEvent evt) {
                    IndexColorModel icm = (IndexColorModel) image.getColorModel();
                    int[] rgbs = new int[2];
                    icm.getRGBs(rgbs);
                    Color c0 = JColorChooser.showDialog(label,
                         "Choose background", new Color(rgbs[0]));
                    Color c1 = JColorChooser.showDialog(label,
                         "Choose foreground", new Color(rgbs[1]));
                    rgbs[0] = c0.getRGB();
                    rgbs[1] = c1.getRGB();
                    icm = new IndexColorModel(1, 2, rgbs, 0, false, -1, DataBuffer.TYPE_BYTE);
                    image = new BufferedImage(icm, image.getRaster(), false, null);
                    label.setIcon(new ImageIcon(image));
          f.getContentPane().add(label);
          f.pack();
          f.show();
}