| /* |
| * Copyright (c) 2004, 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package sun.swing; |
| |
| import java.awt.*; |
| import java.awt.image.*; |
| import java.util.*; |
| |
| /** |
| * A base class used for icons or images that are expensive to paint. |
| * A subclass will do the following: |
| * <ol> |
| * <li>Invoke <code>paint</code> when you want to paint the image, |
| * if you are implementing <code>Icon</code> you'll invoke this from |
| * <code>paintIcon</code>. |
| * The args argument is useful when additional state is needed. |
| * <li>Override <code>paintToImage</code> to render the image. The code that |
| * lives here is equivalent to what previously would go in |
| * <code>paintIcon</code>, for an <code>Icon</code>. |
| * </ol> |
| * The two ways to use this class are: |
| * <ol> |
| * <li>Invoke <code>paint</code> to draw the cached reprensentation at |
| * the specified location. |
| * <li>Invoke <code>getImage</code> to get the cached reprensentation and |
| * draw the image yourself. This is primarly useful when you are not |
| * using <code>VolatileImage</code>. |
| * </ol> |
| * |
| * |
| */ |
| public abstract class CachedPainter { |
| // CacheMap maps from class to ImageCache. |
| private static final Map<Object,ImageCache> cacheMap = |
| new HashMap<Object,ImageCache>(); |
| |
| |
| private static ImageCache getCache(Object key) { |
| synchronized(CachedPainter.class) { |
| ImageCache cache = cacheMap.get(key); |
| if (cache == null) { |
| cache = new ImageCache(1); |
| cacheMap.put(key, cache); |
| } |
| return cache; |
| } |
| } |
| |
| /** |
| * Creates an instance of <code>CachedPainter</code> that will cache up |
| * to <code>cacheCount</code> images of this class. |
| * |
| * @param cacheCount Max number of images to cache |
| */ |
| public CachedPainter(int cacheCount) { |
| getCache(getClass()).setMaxCount(cacheCount); |
| } |
| |
| /** |
| * Renders the cached image to the the passed in <code>Graphic</code>. |
| * If there is no cached image <code>paintToImage</code> will be invoked. |
| * <code>paintImage</code> is invoked to paint the cached image. |
| * |
| * @param c Component rendering to, this may be null. |
| * @param g Graphics to paint to |
| * @param x X-coordinate to render to |
| * @param y Y-coordinate to render to |
| * @param w Width to render in |
| * @param h Height to render in |
| * @param arg Variable arguments that will be passed to paintToImage |
| */ |
| public void paint(Component c, Graphics g, int x, |
| int y, int w, int h, Object... args) { |
| if (w <= 0 || h <= 0) { |
| return; |
| } |
| if (c != null) { |
| synchronized(c.getTreeLock()) { |
| synchronized(CachedPainter.class) { |
| // If c is non-null, synchronize on the tree lock. |
| // This is necessary because asking for the |
| // GraphicsConfiguration will grab a tree lock. |
| paint0(c, g, x, y, w, h, args); |
| } |
| } |
| } |
| else { |
| synchronized(CachedPainter.class) { |
| paint0(c, g, x, y, w, h, args); |
| } |
| } |
| } |
| |
| private void paint0(Component c, Graphics g, int x, |
| int y, int w, int h, Object... args) { |
| Object key = getClass(); |
| GraphicsConfiguration config = getGraphicsConfiguration(c); |
| ImageCache cache = getCache(key); |
| Image image = cache.getImage(key, config, w, h, args); |
| int attempts = 0; |
| do { |
| boolean draw = false; |
| if (image instanceof VolatileImage) { |
| // See if we need to recreate the image |
| 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) { |
| // Recreate the image |
| image = createImage(c, w, h, config, args); |
| cache.setImage(key, config, w, h, args, image); |
| draw = true; |
| } |
| if (draw) { |
| // Render to the Image |
| Graphics g2 = image.getGraphics(); |
| paintToImage(c, image, g2, w, h, args); |
| g2.dispose(); |
| } |
| |
| // Render to the passed in Graphics |
| paintImage(c, g, x, y, w, h, image, args); |
| |
| // If we did this 3 times and the contents are still lost |
| // assume we're painting to a VolatileImage that is bogus and |
| // give up. Presumably we'll be called again to paint. |
| } while ((image instanceof VolatileImage) && |
| ((VolatileImage)image).contentsLost() && ++attempts < 3); |
| } |
| |
| /** |
| * Paints the representation to cache to the supplied Graphics. |
| * |
| * @param c Component painting to, may be null. |
| * @param image Image to paint to |
| * @param g Graphics to paint to, obtained from the passed in Image. |
| * @param w Width to paint to |
| * @param h Height to paint to |
| * @param args Arguments supplied to <code>paint</code> |
| */ |
| protected abstract void paintToImage(Component c, Image image, Graphics g, |
| int w, int h, Object[] args); |
| |
| |
| /** |
| * Paints the image to the specified location. |
| * |
| * @param c Component painting to |
| * @param g Graphics to paint to |
| * @param x X coordinate to paint to |
| * @param y Y coordinate to paint to |
| * @param w Width to paint to |
| * @param h Height to paint to |
| * @param image Image to paint |
| * @param args Arguments supplied to <code>paint</code> |
| */ |
| 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); |
| } |
| |
| /** |
| * Creates the image to cache. This returns an opaque image, subclasses |
| * that require translucency or transparency will need to override this |
| * method. |
| * |
| * @param c Component painting to |
| * @param w Width of image to create |
| * @param h Height to image to create |
| * @param config GraphicsConfiguration that will be |
| * rendered to, this may be null. |
| * @param args Arguments passed to paint |
| */ |
| protected Image createImage(Component c, int w, int h, |
| GraphicsConfiguration config, Object[] args) { |
| if (config == null) { |
| return new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); |
| } |
| return config.createCompatibleVolatileImage(w, h); |
| } |
| |
| /** |
| * Clear the image cache |
| */ |
| protected void flush() { |
| synchronized(CachedPainter.class) { |
| getCache(getClass()).flush(); |
| } |
| } |
| |
| private GraphicsConfiguration getGraphicsConfiguration(Component c) { |
| if (c == null) { |
| return null; |
| } |
| return c.getGraphicsConfiguration(); |
| } |
| } |