/*
    *  File: ColorSpot.java 
    *  Copyright (c) 2004-2007  Peter Kliem (Peter.Kliem@jaret.de)
    *  A commercial license is available, see http://www.jaret.de.
    *
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Common Public License v1.0
    * which accompanies this distribution, and is available at
    * http://www.eclipse.org/legal/cpl-v10.html
   */
  package de.jaret.util.ui;
  
  import org.eclipse.swt.SWT;
  import org.eclipse.swt.events.PaintEvent;
  import org.eclipse.swt.events.PaintListener;
  import org.eclipse.swt.graphics.Color;
  import org.eclipse.swt.graphics.GC;
  import org.eclipse.swt.graphics.Point;
  import org.eclipse.swt.graphics.RGB;
  import org.eclipse.swt.widgets.Canvas;
  import org.eclipse.swt.widgets.Composite;
  import org.eclipse.swt.widgets.Display;
  
  /**
   * Custom widget showing a colored spot.
   * 
   * @author Peter Kliem
   * @version $Id: SmileyWidget.java 242 2007-02-11 21:05:07Z olk $
   */
  public class ColorSpot extends Canvas {
      /** default prefreed size. */
      private static final int PREFSIZE_DEFAULT = 10;
      /** default color. */
      private static final RGB COLOR_DEFAULT = new RGB(255, 0, 0);
  
      /** the preferred size. */
      private int _preferredSize = PREFSIZE_DEFAULT;
      /** the color (allocated). */
      private Color _spotColor;
      /** the rgb value for the color. */
      private RGB _spotRGB = COLOR_DEFAULT;
  
      /**
       * Construct a spot.
       * 
       * @param parent parent composite
       * @param style style bits
       */
      public ColorSpot(Composite parent, int style) {
          super(parent, style);
          addPaintListener(new PaintListener() {
              public void paintControl(PaintEvent event) {
                  onPaint(event);
              }
          });
          setBackground(parent.getBackground());
      }
  
      /**
       * The paint method simply paints a spot on the whole area.
       * 
       * @param event paint event
       */
      private void onPaint(PaintEvent event) {
          GC gc = event.gc;
          int width = getClientArea().width;
          int height = getClientArea().height;
  
          Color bg = gc.getBackground();
  
          gc.setBackground(getColorIntern());
          gc.fillOval(0, 0, width - 1, height - 1);
  
          gc.setBackground(bg);
          gc.drawOval(0, 0, width - 1, height - 1);
  
      }
  
      /**
       * Get the allocated color. Allocates the color from the rgb value if not already done.
       * 
       * @return the color
       */
      private Color getColorIntern() {
          if (_spotColor != null) {
              return _spotColor;
          }
          _spotColor = new Color(Display.getCurrent(), _spotRGB);
          return _spotColor;
      }
  
      /**
       * Get the color of the spot.
       * 
       * @return RGB
       */
      public RGB getSpotRGB() {
          return _spotRGB;
      }
 
     /**
      * Set the color of the spot as RGB. Freeing of the color will be accomplished by the widget.
      * 
      * @param spotRGB color as RGB
      */
     public void setSpotRGB(RGB spotRGB) {
         _spotRGB = spotRGB;
         if (_spotColor != null) {
             _spotColor.dispose();
             _spotColor = null;
         }
     }
 
     /**
      * {@inheritDoc} Dispose the color.
      */
     public void dispose() {
         super.dispose();
         if (_spotColor != null) {
             _spotColor.dispose();
         }
     }
 
     /**
      * {@inheritDoc} Uses the hint if set and the preferred size.
      */
     public Point computeSize(int whint, int hhint) {
         if (whint != SWT.DEFAULT && hhint != SWT.DEFAULT) {
             return new Point(whint, hhint);
         }
         if (whint != SWT.DEFAULT) {
             return new Point(whint, _preferredSize);
         }
         if (hhint != SWT.DEFAULT) {
             return new Point(_preferredSize, hhint);
         }
         return new Point(_preferredSize, _preferredSize);
 
     }
 
     /**
      * {@inheritDoc} Simply delegates to computeSize(int, int).
      */
     public Point computeSize(int hint, int hint2, boolean changed) {
         return computeSize(hint, hint2);
     }
 
     /**
      * Get the preferred size.
      * 
      * @return preferred size
      */
     public int getPreferredSize() {
         return _preferredSize;
     }
 
     /**
      * Set the preferred size.
      * 
      * @param preferredSize preferred size (width and height)
      */
     public void setPreferredSize(int preferredSize) {
         _preferredSize = preferredSize;
     }
 
 }