/*
    * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
    * the spring framework, http://el4j.sf.net
    * Copyright (C) 2005 by ELCA Informatique SA, Av. de la Harpe 22-24,
    * 1000 Lausanne, Switzerland, http://www.elca.ch
    *
    * EL4J is published under the GNU Lesser General Public License (LGPL)
    * Version 2.1. See http://www.gnu.org/licenses/
    *
   * This program 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.
   *
   * For alternative licensing, please contact info@elca.ch
   */
  package ch.elca.el4j.services.gui.swing.splash;
  
  import java.awt.Dimension;
  import java.awt.EventQueue;
  import java.awt.Frame;
  import java.awt.Graphics;
  import java.awt.Image;
  import java.awt.MediaTracker;
  import java.awt.Rectangle;
  import java.awt.Toolkit;
  import java.awt.Window;
  
  /**
   * Shows an image as GUI splash screen. Typical usage pattern:
   * <ul>
   * <li> Display splash screen (early to show something to user rapidly)
   * <li> Make some application initialization, such as set up spring app context
   * <li> Launch the main application window via GuiApplication.launch
   * </ul>
   *
   * @svnLink $Revision: 3875 $;$Date: 2009-08-04 14:35:53 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/swing/src/main/java/ch/elca/el4j/services/gui/swing/splash/ImageSplashScreen.java $
   *
   * @author Philipp Oser (POS)
   * @author Stefan Wismer (SWI)
   */
  public class ImageSplashScreen {
  	
  	/**
  	 * Default EL4J splash screen png.
  	 */
  	public static final String DEFAULT_SPLASH_SCREEN
  		= "/ch/elca/el4j/gui/swing/splash/resources/splash-screen.png";
  	
  	/**
  	 * The frame containing the splash image.
  	 */
  	private Frame m_frame;
  	
  	/**
  	 * The splash image.
  	 */
  	private Image m_image;
  	
  	/**
  	 * The resource path where the image is located.
  	 */
  	private String m_imageResourcePath;
  
  	/**
  	 * The splash window.
  	 */
  	private static class SplashWindow extends Window {
  		/**
  		 * The splash image.
  		 */
  		private Image m_splashImage;
  		
  		/**
  		 * @param parent    the parent frame
  		 * @param image     the splash image
  		 */
  		public SplashWindow(Frame parent, Image image) {
  			super(parent);
  			this.m_splashImage = image;
  			setSize(parent.getSize());
  			setLocation(parent.getLocation());
  			setVisible(true);
  		}
  		
  		/** {@inheritDoc} */
  		@Override
  		public void paint(Graphics graphics) {
  			if (m_splashImage != null) {
  				graphics.drawImage(m_splashImage, 0, 0, this);
  			}
  		}
  	}
  	
  	
  	/**
  	 * Display splash screen with default this image.
  	 */
  	public ImageSplashScreen() {
 		this(DEFAULT_SPLASH_SCREEN);
 	}
 
 	/**
 	 * Display splash screen with this image.
 	 *
 	 * @param imageResourcePath
 	 *            path to image file
 	 */
 	public ImageSplashScreen(String imageResourcePath) {
 		this.m_imageResourcePath = imageResourcePath;
 		splash();
 	}
 
 	/**
 	 * Display splash screen with this image.
 	 *
 	 * @param image
 	 *            image to show
 	 */
 	public ImageSplashScreen(Image image) {
 		this.m_image = image;
 		splash();
 	}
 
 	/**
 	 * Show the splash screen.
 	 */
 	protected void splash() {
 		m_frame = new Frame();
 		if (m_image == null) {
 			m_image = loadImage(m_imageResourcePath);
 			if (m_image == null) {
 				return;
 			}
 		}
 		MediaTracker mediaTracker = new MediaTracker(m_frame);
 		mediaTracker.addImage(m_image, 0);
 		try {
 			mediaTracker.waitForID(0);
 		} catch (InterruptedException e) {
 			return;
 		}
 		m_frame.setSize(m_image.getWidth(null), m_image.getHeight(null));
 		center();
 		new SplashWindow(m_frame, m_image);
 	}
 
 	/**
 	 * Stop this splash screen in the EDT.
 	 */
 	public void dispose() {
 		EventQueue.invokeLater(new Runnable() {
 			public void run() {
 				m_frame.dispose();
 				m_frame = null;
 			}
 		});
 	}
 
 	/**
 	 * @param path    path to image file
 	 * @return        the loaded image
 	 */
 	private Image loadImage(String path) {
 		java.net.URL url = getClass().getResource(path);
 		if (url == null) {
 			return null;
 		} else {
 			return Toolkit.getDefaultToolkit().createImage(url);
 		}
 	}
 
 	/**
 	 * Center the splash screen.
 	 */
 	private void center() {
 		Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
 		Rectangle r = m_frame.getBounds();
 		m_frame.setLocation((screen.width - r.width) / 2,
 			(screen.height - r.height) / 2);
 	}
 }