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| 1 | +/* | |
| 2 | + * Copyright (c) 2004, 2006, Oracle and/or its affiliates. All rights reserved. | |
| 3 | + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 | + * | |
| 5 | + * This code is free software; you can redistribute it and/or modify it | |
| 6 | + * under the terms of the GNU General Public License version 2 only, as | |
| 7 | + * published by the Free Software Foundation. Oracle designates this | |
| 8 | + * particular file as subject to the "Classpath" exception as provided | |
| 9 | + * by Oracle in the LICENSE file that accompanied this code. | |
| 10 | + * | |
| 11 | + * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 12 | + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 | + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 | + * version 2 for more details (a copy is included in the LICENSE file that | |
| 15 | + * accompanied this code). | |
| 16 | + * | |
| 17 | + * You should have received a copy of the GNU General Public License version | |
| 18 | + * 2 along with this work; if not, write to the Free Software Foundation, | |
| 19 | + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 20 | + * | |
| 21 | + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| 22 | + * or visit www.oracle.com if you need additional information or have any | |
| 23 | + * questions. | |
| 24 | + */ | |
| 25 | +package sun.swing; | |
| 26 | + | |
| 27 | +import java.awt.*; | |
| 28 | +import java.awt.image.*; | |
| 29 | +import java.util.*; | |
| 30 | + | |
| 31 | +/** | |
| 32 | + * A base class used for icons or images that are expensive to paint. | |
| 33 | + * A subclass will do the following: | |
| 34 | + * <ol> | |
| 35 | + * <li>Invoke <code>paint</code> when you want to paint the image, | |
| 36 | + * if you are implementing <code>Icon</code> you'll invoke this from | |
| 37 | + * <code>paintIcon</code>. | |
| 38 | + * The args argument is useful when additional state is needed. | |
| 39 | + * <li>Override <code>paintToImage</code> to render the image. The code that | |
| 40 | + * lives here is equivalent to what previously would go in | |
| 41 | + * <code>paintIcon</code>, for an <code>Icon</code>. | |
| 42 | + * </ol> | |
| 43 | + * The two ways to use this class are: | |
| 44 | + * <ol> | |
| 45 | + * <li>Invoke <code>paint</code> to draw the cached reprensentation at | |
| 46 | + * the specified location. | |
| 47 | + * <li>Invoke <code>getImage</code> to get the cached reprensentation and | |
| 48 | + * draw the image yourself. This is primarly useful when you are not | |
| 49 | + * using <code>VolatileImage</code>. | |
| 50 | + * </ol> | |
| 51 | + * | |
| 52 | + * | |
| 53 | + */ | |
| 54 | +public abstract class CachedPainter { | |
| 55 | + // CacheMap maps from class to ImageCache. | |
| 56 | + private static final Map<Object,ImageCache> cacheMap = | |
| 57 | + new HashMap<Object,ImageCache>(); | |
| 58 | + | |
| 59 | + | |
| 60 | + private static ImageCache getCache(Object key) { | |
| 61 | + synchronized(CachedPainter.class) { | |
| 62 | + ImageCache cache = cacheMap.get(key); | |
| 63 | + if (cache == null) { | |
| 64 | + cache = new ImageCache(1); | |
| 65 | + cacheMap.put(key, cache); | |
| 66 | + } | |
| 67 | + return cache; | |
| 68 | + } | |
| 69 | + } | |
| 70 | + | |
| 71 | + /** | |
| 72 | + * Creates an instance of <code>CachedPainter</code> that will cache up | |
| 73 | + * to <code>cacheCount</code> images of this class. | |
| 74 | + * | |
| 75 | + * @param cacheCount Max number of images to cache | |
| 76 | + */ | |
| 77 | + public CachedPainter(int cacheCount) { | |
| 78 | + getCache(getClass()).setMaxCount(cacheCount); | |
| 79 | + } | |
| 80 | + | |
| 81 | + /** | |
| 82 | + * Renders the cached image to the the passed in <code>Graphic</code>. | |
| 83 | + * If there is no cached image <code>paintToImage</code> will be invoked. | |
| 84 | + * <code>paintImage</code> is invoked to paint the cached image. | |
| 85 | + * | |
| 86 | + * @param c Component rendering to, this may be null. | |
| 87 | + * @param g Graphics to paint to | |
| 88 | + * @param x X-coordinate to render to | |
| 89 | + * @param y Y-coordinate to render to | |
| 90 | + * @param w Width to render in | |
| 91 | + * @param h Height to render in | |
| 92 | + * @param arg Variable arguments that will be passed to paintToImage | |
| 93 | + */ | |
| 94 | + public void paint(Component c, Graphics g, int x, | |
| 95 | + int y, int w, int h, Object... args) { | |
| 96 | + if (w <= 0 || h <= 0) { | |
| 97 | + return; | |
| 98 | + } | |
| 99 | + if (c != null) { | |
| 100 | + synchronized(c.getTreeLock()) { | |
| 101 | + synchronized(CachedPainter.class) { | |
| 102 | + // If c is non-null, synchronize on the tree lock. | |
| 103 | + // This is necessary because asking for the | |
| 104 | + // GraphicsConfiguration will grab a tree lock. | |
| 105 | + paint0(c, g, x, y, w, h, args); | |
| 106 | + } | |
| 107 | + } | |
| 108 | + } | |
| 109 | + else { | |
| 110 | + synchronized(CachedPainter.class) { | |
| 111 | + paint0(c, g, x, y, w, h, args); | |
| 112 | + } | |
| 113 | + } | |
| 114 | + } | |
| 115 | + | |
| 116 | + private void paint0(Component c, Graphics g, int x, | |
| 117 | + int y, int w, int h, Object... args) { | |
| 118 | + Object key = getClass(); | |
| 119 | + GraphicsConfiguration config = getGraphicsConfiguration(c); | |
| 120 | + ImageCache cache = getCache(key); | |
| 121 | + Image image = cache.getImage(key, config, w, h, args); | |
| 122 | + int attempts = 0; | |
| 123 | + do { | |
| 124 | + boolean draw = false; | |
| 125 | + if (image instanceof VolatileImage) { | |
| 126 | + // See if we need to recreate the image | |
| 127 | + switch (((VolatileImage)image).validate(config)) { | |
| 128 | + case VolatileImage.IMAGE_INCOMPATIBLE: | |
| 129 | + ((VolatileImage)image).flush(); | |
| 130 | + image = null; | |
| 131 | + break; | |
| 132 | + case VolatileImage.IMAGE_RESTORED: | |
| 133 | + draw = true; | |
| 134 | + break; | |
| 135 | + } | |
| 136 | + } | |
| 137 | + if (image == null) { | |
| 138 | + // Recreate the image | |
| 139 | + image = createImage(c, w, h, config, args); | |
| 140 | + cache.setImage(key, config, w, h, args, image); | |
| 141 | + draw = true; | |
| 142 | + } | |
| 143 | + if (draw) { | |
| 144 | + // Render to the Image | |
| 145 | + Graphics g2 = image.getGraphics(); | |
| 146 | + paintToImage(c, image, g2, w, h, args); | |
| 147 | + g2.dispose(); | |
| 148 | + } | |
| 149 | + | |
| 150 | + // Render to the passed in Graphics | |
| 151 | + paintImage(c, g, x, y, w, h, image, args); | |
| 152 | + | |
| 153 | + // If we did this 3 times and the contents are still lost | |
| 154 | + // assume we're painting to a VolatileImage that is bogus and | |
| 155 | + // give up. Presumably we'll be called again to paint. | |
| 156 | + } while ((image instanceof VolatileImage) && | |
| 157 | + ((VolatileImage)image).contentsLost() && ++attempts < 3); | |
| 158 | + } | |
| 159 | + | |
| 160 | + /** | |
| 161 | + * Paints the representation to cache to the supplied Graphics. | |
| 162 | + * | |
| 163 | + * @param c Component painting to, may be null. | |
| 164 | + * @param image Image to paint to | |
| 165 | + * @param g Graphics to paint to, obtained from the passed in Image. | |
| 166 | + * @param w Width to paint to | |
| 167 | + * @param h Height to paint to | |
| 168 | + * @param args Arguments supplied to <code>paint</code> | |
| 169 | + */ | |
| 170 | + protected abstract void paintToImage(Component c, Image image, Graphics g, | |
| 171 | + int w, int h, Object[] args); | |
| 172 | + | |
| 173 | + | |
| 174 | + /** | |
| 175 | + * Paints the image to the specified location. | |
| 176 | + * | |
| 177 | + * @param c Component painting to | |
| 178 | + * @param g Graphics to paint to | |
| 179 | + * @param x X coordinate to paint to | |
| 180 | + * @param y Y coordinate to paint to | |
| 181 | + * @param w Width to paint to | |
| 182 | + * @param h Height to paint to | |
| 183 | + * @param image Image to paint | |
| 184 | + * @param args Arguments supplied to <code>paint</code> | |
| 185 | + */ | |
| 186 | + protected void paintImage(Component c, Graphics g, | |
| 187 | + int x, int y, int w, int h, Image image, | |
| 188 | + Object[] args) { | |
| 189 | + g.drawImage(image, x, y, null); | |
| 190 | + } | |
| 191 | + | |
| 192 | + /** | |
| 193 | + * Creates the image to cache. This returns an opaque image, subclasses | |
| 194 | + * that require translucency or transparency will need to override this | |
| 195 | + * method. | |
| 196 | + * | |
| 197 | + * @param c Component painting to | |
| 198 | + * @param w Width of image to create | |
| 199 | + * @param h Height to image to create | |
| 200 | + * @param config GraphicsConfiguration that will be | |
| 201 | + * rendered to, this may be null. | |
| 202 | + * @param args Arguments passed to paint | |
| 203 | + */ | |
| 204 | + protected Image createImage(Component c, int w, int h, | |
| 205 | + GraphicsConfiguration config, Object[] args) { | |
| 206 | + if (config == null) { | |
| 207 | + return new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); | |
| 208 | + } | |
| 209 | + return config.createCompatibleVolatileImage(w, h); | |
| 210 | + } | |
| 211 | + | |
| 212 | + /** | |
| 213 | + * Clear the image cache | |
| 214 | + */ | |
| 215 | + protected void flush() { | |
| 216 | + synchronized(CachedPainter.class) { | |
| 217 | + getCache(getClass()).flush(); | |
| 218 | + } | |
| 219 | + } | |
| 220 | + | |
| 221 | + private GraphicsConfiguration getGraphicsConfiguration(Component c) { | |
| 222 | + if (c == null) { | |
| 223 | + return null; | |
| 224 | + } | |
| 225 | + return c.getGraphicsConfiguration(); | |
| 226 | + } | |
| 227 | +} | |