package org.apidesign.extensibleicon;

 import java.awt.Component;

 import java.awt.Graphics;

 import java.io.IOException;

 import org.openide.util.Lookup;

 import org.openide.util.lookup.AbstractLookup;

 import org.openide.util.lookup.InstanceContent;

 // BEGIN: ext.modifiable.icon

 public final class ModifiableIcon implements ExtIcon {

     // AbstractLookup is helper implementation

     // so that people do not need to write its own

     // lookup from scratch

     private AbstractLookup lookup;

     // InstanceContent is interface that gives

     // "creator of the lookup" more rights, like

     // ability to modify the content

     private InstanceContent ic;

     ModifiableIcon() {

         ic = new InstanceContent();

         lookup = new AbstractLookup(ic);

     }

     public Lookup getLookup() {

         return lookup;

     }

     public void markModified() {

         if (lookup.lookup(ModifiedImpl.class) == null) {

             ic.add(new ModifiedImpl());

         }

     }

     private final class ModifiedImpl implements Modified {

         public void save() throws IOException {

             // save somehow

         }

         public void discard() throws IOException {

             // discard changes

         }

     }

 // FINISH: ext.modifiable.icon

     public void paintIcon(Component c, Graphics g, int x, int y) {

         g.fillRect(x, y, 16, 16);

     }

     public int getIconWidth() {

         return 16;

     }

     public int getIconHeight() {

         return 16;

     }

 }