/**
 * ColorPicker.java  1.00 97/04/12 Merlin Hughes
 *
 * Copyright (c) 1997 Prominence Dot Com, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * for commercial and non-commercial purposes and without fee is
 * hereby granted provided that this copyright notice appears in
 * all copies.
 *
 * http://prominence.com/                  merlin@prominence.com
 */
import java.awt.*;
import java.awt.event.MouseEvent;

public class ColorPicker extends Canvas {
  protected static final int LEVELS = 6;
  protected int r, g, b;

  public ColorPicker (Color color) {
    r = color.getRed ();
    g = color.getGreen ();
    b = color.getBlue ();
    enableEvents (AWTEvent.MOUSE_EVENT_MASK);
  }

  public ColorPicker () {
    this (Color.black);
  }

  public Dimension getPreferredSize () {
    return new Dimension (150, 60);
  }

  public void paint (Graphics g) {
    int h = getSize ().width / (LEVELS + 3 + LEVELS);
    int v = getSize ().height / (LEVELS);

    for (int red = 0; red < LEVELS; ++ red) {
      for (int green = 0; green < LEVELS; ++ green) {
        g.setColor (new Color (red * 255 / (LEVELS - 1),
                               green * 255 / (LEVELS - 1),
                               b));
        g.fillRect (red * h, green * v, h, v);
      }
    }
    int x = LEVELS * h  + h / 2;
    int y = v / 2 + v * (b * (LEVELS - 1) / 255);
    g.setColor (getForeground ());
    g.drawLine (x, y, x + 2 * h - 1, y);
    for (int blue = 0; blue < LEVELS; ++ blue) {
      g.setColor (new Color (0, 0, blue * 255 / (LEVELS - 1)));
      g.fillRect ((LEVELS + 1) * h, blue * v, h, v);
    }
    g.setColor (new Color (r, this.g, b));
    g.fillRect ((LEVELS + 3) * h, 0, h * LEVELS, v * LEVELS);
  }

  /*
   * This code allows us to catch mouse events without registering listeners.
   */
  protected void processMouseEvent (MouseEvent e) {
    if (e.getID () == MouseEvent.MOUSE_PRESSED) {
      mousePressed (e);
    }
    super.processMouseEvent (e);
  }

  public void mousePressed (MouseEvent e) {
    int h = getSize ().width / (LEVELS + 3 + LEVELS);
    int v = getSize ().height / (LEVELS);

    if (e.getX () < LEVELS * h) { // in swatch area
      r = (e.getX () / h) * 255 / (LEVELS - 1);
      r = (r < 0) ? 0 : (r > 255) ? 255 : r;
      g = (e.getY () / v) * 255 / (LEVELS - 1);
      g = (g < 0) ? 0 : (g > 255) ? 255 : g;
      repaint ();
    } else if (e.getX () < (LEVELS + 3) * h) { // in blue bar
      b = (e.getY () / v) * 255 / (LEVELS - 1);
      b = (b < 0) ? 0 : (b > 255) ? 255 : b;
      repaint ();
    } else { // in select square
      postColorEvent ();
    }
  }

  /*
   * This code posts a new ColorEvent to the system event queue.
   */
  protected void postColorEvent () {
    ColorEvent e = new ColorEvent (this, new Color (r, g, b));
    Toolkit toolkit = getToolkit ();
    EventQueue queue = toolkit.getSystemEventQueue ();
    queue.postEvent (e);
  }

  // alternatively:
  // dispatchEvent (new ColorEvent (this, new Color (r, g, b)));

  /*
   * This code maintains a list of current ColorListeners.
   */
  protected ColorListener colorListener;

  public synchronized void addColorListener (ColorListener l) {
    colorListener = ColorEventMulticaster.add (colorListener, l);
  }

  public synchronized void removeColorListener (ColorListener l) {
    colorListener = ColorEventMulticaster.remove (colorListener, l);
  }

  /*
   * This code processes the dispatch of ColorEvents to the ColorListeners.
   */
  protected void processEvent (AWTEvent e) {
    if (e instanceof ColorEvent) {
      processColorEvent ((ColorEvent) e);
    } else {
      super.processEvent (e);
    }
  }

  protected synchronized void processColorEvent (ColorEvent e) {
    if (colorListener != null)
      colorListener.colorPicked (e);
  }
}

  /*
   * Using a Vector to store the listeners
   *
  protected Vector colorListeners = new Vector ();

  public void addColorListener (ColorListener l) {
    colorListeners.addElement (l);
  }

  public void removeColorListener (ColorListener l) {
    colorListeners.removeElement (l);
  }

  protected void processColorEvent (ColorEvent e) {
    synchronized (colorListeners) {
      for (int i = 0; i < colorListeners.size (); ++ i) {
        ((ColorListener) colorListeners.elementAt (i)).colorPicked (e);
      }
    }
  }
   *
   */