/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2008 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.gui.look.painters;

import java.awt.Component;
import java.awt.Graphics;
import java.awt.GraphicsConfiguration;
import java.awt.Image;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.awt.image.VolatileImage;
import java.util.HashMap;
import java.util.Map;

/**
 * A cached painter.
 *
 * @author Ingo Mierswa
 * @version $Id: AbstractCachedPainter.java,v 1.2 2008/05/09 19:23:16 ingomierswa Exp $
 */
public abstract class AbstractCachedPainter {

	protected static final Map<Object, Cache> cacheMap = new HashMap<Object, Cache>();

	public AbstractCachedPainter(int cacheCount) {
		getCache(getClass()).setMaxCount(cacheCount);
	}

	/** Paints the representation to cache to the supplied Graphics. */
	protected abstract void paintToImage(Component c, Graphics g, int w, int h, Object[] args);
	
	public void paint(Component c, Graphics g, int x, int y, int w, int h, Object[] args) {
		if ((w <= 0) || (h <= 0)) {
			return;
		}
		Object key = getClass();
		GraphicsConfiguration config = c.getGraphicsConfiguration();
		Cache cache = getCache(key);
		Image image = cache.getImage(key, config, w, h, args);
		int attempts = 0;
		do {
			boolean draw = false;
			if (image instanceof VolatileImage) {
				switch (((VolatileImage) image).validate(config)) {
				case VolatileImage.IMAGE_INCOMPATIBLE:
					((VolatileImage) image).flush();
					image = null;
					break;
				case VolatileImage.IMAGE_RESTORED:
					draw = true;
					break;
				}
			}
			if (image == null) {
				image = createImage(c, w, h, config);
				cache.setImage(key, config, w, h, args, image);
				draw = true;
			}
			if (draw) {
				Graphics g2 = image.getGraphics();
				paintToImage(c, g2, w, h, args);
				g2.dispose();
			}

			paintImage(c, g, x, y, w, h, image, args);
		} while ((image instanceof VolatileImage) && ((VolatileImage) image).contentsLost() && (++attempts < 3));
	}

	protected void paintImage(Component c, Graphics g, int x, int y, int w, int h, Image image, Object[] args) {
		g.drawImage(image, x, y, null);
	}

	protected Image createImage(Component c, int w, int h, GraphicsConfiguration config) {
		if (config == null) {
			return new BufferedImage(w, h, BufferedImage.TYPE_4BYTE_ABGR);
		}
		return config.createCompatibleImage(w, h, Transparency.BITMASK);
	}
	
	public static void clearCache() {
		synchronized (cacheMap) {
			cacheMap.clear();
		}
	}

	private static Cache getCache(Object key) {
		synchronized (cacheMap) {
			Cache cache = cacheMap.get(key);
			if (cache == null) {
				cache = new Cache(1);
				cacheMap.put(key, cache);
			}
			return cache;
		}
	}
}