/*
    *  XNap Commons
    *
    *  Copyright (C) 2005  Steffen Pingel
    *
    *  This library is free software; you can redistribute it and/or
    *  modify it under the terms of the GNU Lesser General Public
    *  License as published by the Free Software Foundation; either
    *  version 2.1 of the License, or (at your option) any later version.
   *
   *  This library is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   *  Lesser General Public License for more details.
   *
   *  You should have received a copy of the GNU Lesser General Public
   *  License along with this library; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  package org.xnap.commons.gui.util;
  
  import java.awt.Component;
  import java.awt.Graphics;
  import java.awt.Image;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.List;
  
  import javax.swing.Icon;
  import javax.swing.ImageIcon;
  
  /***
   * @author Steffen Pingel
   */
  public class IconHelper {
  
  	/***
  	 * The default path to search for icons.
  	 */
      public static final String DEFAULT_ICON_PATH = "icons/";
  	
  	public static ClassLoader classLoader = IconHelper.class.getClassLoader();
  
      /***
       * List bigger sizes first. Scaling down looks nicer than scaling up.
       */
      private static final int[] DEFAULT_ICON_SUBDIRECTORIES = {
  		64, 52, 32, 22, 16
      };
  
      private static String iconPath = DEFAULT_ICON_PATH;
      private static int[] subDirectories = DEFAULT_ICON_SUBDIRECTORIES;
      
      public static final Icon getIcon(String filename, int size, boolean createEmptyIcon)
  	{
      	if (filename == null) {
      		return createEmptyIcon ? new EmptyIcon(size) : null;
      	}
  	
      	ImageIcon icon = getImage(size, filename);
      	if (icon != null) {
      		if (icon.getIconWidth() != size || icon.getIconHeight() != size) {
      			// scale icon to fit size requirements
      			icon = new ImageIcon(icon.getImage().getScaledInstance
      				(size, size, Image.SCALE_SMOOTH));
      		}
  
      		return icon;
      	}
      	else {
      		return createEmptyIcon ? new EmptyIcon(size) : null;
      	}
  	}
  
      /***
       * @return never returns null
       * @see #getIcon(String, int, boolean)
       */
      public static final Icon getIcon(String filename, int size)
      {
  		return getIcon(filename, size, true);
      }
      
      /***
       * Searches {@link #iconPath} for <code>filename</code>. 
       * @return null, if <code>filename</code> does not exists
       */
      public static final ImageIcon getImage(String filename)
      {
  		URL url = classLoader.getResource(iconPath + filename);
  		return (url != null) ? getImageIcon(url) : null;
      }
  
  	public static final ImageIcon getImage(int size, String filename)
      {
  		URL url = getImageURL(size, filename);
  		if (url != null) {
  			return getImageIcon(url);
  		}
 		
 		// look for the icon in other subdirecotries
 		for (int subDirectory : subDirectories) {
 			if (subDirectory == size) {
 				continue;
 			}
 			url = getImageURL(subDirectory, filename);
 			if (url != null) {
 				return getImageIcon(url);
 			}
 		}
 		
 		return null;
 	}
 
 	public static final URL getImageURL(int size, String filename)
     {
 		return classLoader.getResource(DEFAULT_ICON_PATH + size + "/" + filename);
     }
 	
 	public static final ImageIcon getImageIcon(URL url) 
 	{
 		return new ImageIcon(url);
 	}
 	
     public static final Icon getEmptyIcon(int size)
     {
 		return new EmptyIcon(size);
     }	
 
 	public static final List<? extends Image> getApplicationIcons(String filename) {
 		List<Image> icons = new ArrayList<Image>();
 		for (int subDirectory : subDirectories) {
 			URL url = getImageURL(subDirectory, filename);
 			if (url != null) {
 				icons.add(getImageIcon(url).getImage());
 			}
 		}
 		return (icons.isEmpty()) ? null : icons;
 	}
 	
     public static final Icon getListIcon(String filename)
     {
 		return getIcon(filename, 32, false);
     }
 
     public static final Icon getButtonIcon(String filename)
     {
 		return getIcon(filename, 16, false);
     }
 
     public static final Icon getMenuIcon(String filename)
     {
 		return getIcon(filename, 16);
     }
 
     public static final Icon getStatusBarIcon(String filename)
     {
 		return getIcon(filename, 16, false);
     }
 
     public static final ImageIcon getSystemTrayIcon(String filename)
     {
     	Icon icon = getIcon(filename, 16, false);
 		return (icon instanceof ImageIcon) ? (ImageIcon) icon : null;
     }
 
     public static final Icon getTableIcon(String filename)
     {
 		return getIcon(filename, 14, true);
     }
 
     public static final Icon getTabTitleIcon(String filename)
     {
 		return getIcon(filename, 16, false);
     }
 
     public static final Icon getTreeIcon(String filename)
     {
 		return getIcon(filename, 16, false);
     }
 
     public static final Icon getToolBarIcon(String filename)
     {
 		return getIcon(filename, 22);
     }
 
     public static final Icon getTitleIcon(String filename)
 	{
 		return getIcon(filename, 32, false);
 	}
     
     public static void setIconPath(String iconPath)
     {
     	IconHelper.iconPath = iconPath;
     }
 
     public static void setSubDirectories(int[] subDirectories)
     {
     	IconHelper.subDirectories = subDirectories;
     }
 
     /***
      * Provides an empty, transparent icon.
      */
     public static class EmptyIcon implements Icon
     {
 		private int size;
 
 		/***
 		 * Constructs an empty icon with a width and heigt of 
 		 * <code>size</code>.
 		 */
 		public EmptyIcon(int size)
 		{
 			this.size = size;
 		}
 	
 		public int getIconHeight() 
 		{
 			return size;
 		}
 	
 		public int getIconWidth() 
 		{
 			return size;
 		}
 	
 		public void paintIcon(Component c, Graphics g, int x, int y) 
 		{
 		}	
 	
     }
 
 	public static Icon getActionIcon(String filename)
 	{
 		return getIcon(filename, 16, false);
 	}
 
 }