[udig-devel] Overlay Images

[Jody Garnett <jgarnett@xxxxxxxxxxxxxxx>]

Found the following class (finally) that allows the use of Icons with 
overlays:

Something we can use as an example.
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/*******************************************************************************
* Copyright (c) 2000, 2004 IBM Corporation and others.
* 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
*
* Contributors:
*     IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.team.internal.ui;

import java.util.Arrays;

import org.eclipse.jface.resource.CompositeImageDescriptor;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.graphics.*;

/**
* An OverlayIcon consists of a main icon and several adornments.
*/
public class OverlayIcon extends CompositeImageDescriptor {
   // the base image
   private Image base;
   // the base as a descriptor
   private ImageDescriptor descriptorBase;
   // the overlay images
   private ImageDescriptor[] overlays;
   // the size
   private Point size;
   // the locations
   private int[] locations;
  
   public static final int TOP_LEFT = 0;
   public static final int TOP_RIGHT = 1;
   public static final int BOTTOM_LEFT = 2;
   public static final int BOTTOM_RIGHT = 3;
  
   public static final int DEFAULT_WIDTH= 22;
   public static final int DEFAULT_HEIGHT= 16;
  
   /**
    * OverlayIcon constructor.
    *
    * @param base the base image
    * @param overlays the overlay images
    * @param locations the location of each image
    * @param size the size
    */
   public OverlayIcon(Image base, ImageDescriptor[] overlays, int[] 
locations, Point size) {
       this.base = base;
       this.descriptorBase = null;
       this.overlays = overlays;
       this.locations = locations;
       this.size = size;
   }
  
   /**
    * OverlayIcon constructor.
    *
    * @param base the base image
    * @param overlays the overlay images
    * @param locations the location of each image
    * @param size the size
    */
   public OverlayIcon(ImageDescriptor descriptorBase, ImageDescriptor[] 
overlays, int[] locations, Point size) {
       this.descriptorBase = descriptorBase;
       this.base = null;
       this.overlays = overlays;
       this.locations = locations;
       this.size = size;
   }
  
   protected void drawOverlays(ImageDescriptor[] overlays, int[] 
locations) {
           Point size = getSize();
           for (int i = 0; i < overlays.length; i++) {
               ImageDescriptor overlay = overlays[i];
               ImageData overlayData = overlay.getImageData();
               switch (locations[i]) {
                   case TOP_LEFT:
                       drawImage(overlayData, 0, 0);           
                       break;
                   case TOP_RIGHT:
                       drawImage(overlayData, size.x - 
overlayData.width, 0);           
                       break;
                   case BOTTOM_LEFT:
                       drawImage(overlayData, 0, size.y - 
overlayData.height);           
                       break;
                   case BOTTOM_RIGHT:
                       drawImage(overlayData, size.x - 
overlayData.width, size.y - overlayData.height);           
                       break;
               }
           }
       }

   public boolean equals(Object o) {
       if (! (o instanceof OverlayIcon)) return false;
       OverlayIcon other = (OverlayIcon) o;
       return base.equals(other.base) && Arrays.equals(overlays, 
other.overlays);
   }

   public int hashCode() {
       int code = base.hashCode();
       for (int i = 0; i < overlays.length; i++) {
           code ^= overlays[i].hashCode();
       }
       return code;
   }


   protected void drawCompositeImage(int width, int height) {
       if(descriptorBase != null) {
           ImageData bg;
           if (descriptorBase == null || (bg= 
descriptorBase.getImageData()) == null)
               bg= DEFAULT_IMAGE_DATA;
           drawImage(bg, 0, 0);
       } else {
           drawImage(base.getImageData(), 0, 0);
       }
       drawOverlays(overlays, locations);
   }

   protected Point getSize() {
       return size;
   }
}