1 /*
2 * Copyright (c) 2004, 2015, 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 = new HashMap<>();
57
58 private static ImageCache getCache(Object key) {
59 synchronized(CachedPainter.class) {
60 ImageCache cache = cacheMap.get(key);
61 if (cache == null) {
62 if (key == PainterMultiResolutionCachedImage.class) {
63 cache = new ImageCache(32);
64 } else {
65 cache = new ImageCache(1);
66 }
67 cacheMap.put(key, cache);
68 }
69 return cache;
70 }
71 }
72
73 /**
74 * Creates an instance of <code>CachedPainter</code> that will cache up
75 * to <code>cacheCount</code> images of this class.
76 *
77 * @param cacheCount Max number of images to cache
78 */
79 public CachedPainter(int cacheCount) {
80 getCache(getClass()).setMaxCount(cacheCount);
81 }
82
83 /**
84 * Renders the cached image to the passed in <code>Graphic</code>.
85 * If there is no cached image <code>paintToImage</code> will be invoked.
86 * <code>paintImage</code> is invoked to paint the cached image.
87 *
88 * @param c Component rendering to, this may be null.
89 * @param g Graphics to paint to
90 * @param x X-coordinate to render to
91 * @param y Y-coordinate to render to
92 * @param w Width to render in
93 * @param h Height to render in
94 * @param args Variable arguments that will be passed to paintToImage
95 */
96 public void paint(Component c, Graphics g, int x,
97 int y, int w, int h, Object... args) {
98 if (w <= 0 || h <= 0) {
99 return;
100 }
101 synchronized (CachedPainter.class) {
102 paint0(c, g, x, y, w, h, args);
103 }
104 }
105
106 private Image getImage(Object key, Component c,
107 int baseWidth, int baseHeight,
108 int w, int h, Object... args) {
109 GraphicsConfiguration config = getGraphicsConfiguration(c);
110 ImageCache cache = getCache(key);
111 Image image = cache.getImage(key, config, w, h, args);
112 int attempts = 0;
113 VolatileImage volatileImage = (image instanceof VolatileImage)
114 ? (VolatileImage) image
115 : null;
116 do {
117 boolean draw = false;
118 if (volatileImage != null) {
119 // See if we need to recreate the image
120 switch (volatileImage.validate(config)) {
121 case VolatileImage.IMAGE_INCOMPATIBLE:
122 volatileImage.flush();
123 image = null;
124 break;
125 case VolatileImage.IMAGE_RESTORED:
126 draw = true;
127 break;
128 }
129 }
130 if (image == null) {
131 // Recreate the image
132 image = createImage(c, w, h, config, args);
133 cache.setImage(key, config, w, h, args, image);
134 draw = true;
135 volatileImage = (image instanceof VolatileImage)
136 ? (VolatileImage) image
137 : null;
138 }
139 if (draw) {
140 // Render to the Image
141 Graphics2D g2 = (Graphics2D) image.getGraphics();
142 if (volatileImage == null && (w != baseWidth || h != baseHeight)) {
143 g2.scale((double) w / baseWidth, (double) h / baseHeight);
144 }
145 paintToImage(c, image, g2, baseWidth, baseHeight, args);
146 g2.dispose();
147 }
148
149 // If we did this 3 times and the contents are still lost
150 // assume we're painting to a VolatileImage that is bogus and
151 // give up. Presumably we'll be called again to paint.
152 } while ((volatileImage != null) &&
153 volatileImage.contentsLost() && ++attempts < 3);
154
155 return image;
156 }
157
158 private void paint0(Component c, Graphics g, int x,
159 int y, int w, int h, Object... args) {
160 Object key = getClass();
161 GraphicsConfiguration config = getGraphicsConfiguration(c);
162 ImageCache cache = getCache(key);
163 Image image = cache.getImage(key, config, w, h, args);
164
165 if (image == null) {
166 image = new PainterMultiResolutionCachedImage(w, h);
167 cache.setImage(key, config, w, h, args, image);
168 }
169
170 if (image instanceof PainterMultiResolutionCachedImage) {
171 ((PainterMultiResolutionCachedImage) image).setParams(c, args);
172 }
173
174 // Render to the passed in Graphics
175 paintImage(c, g, x, y, w, h, image, args);
176 }
177
178 /**
179 * Paints the representation to cache to the supplied Graphics.
180 *
181 * @param c Component painting to, may be null.
182 * @param image Image to paint to
183 * @param g Graphics to paint to, obtained from the passed in Image.
184 * @param w Width to paint to
185 * @param h Height to paint to
186 * @param args Arguments supplied to <code>paint</code>
187 */
188 protected abstract void paintToImage(Component c, Image image, Graphics g,
189 int w, int h, Object[] args);
190
191
192 /**
193 * Paints the image to the specified location.
194 *
195 * @param c Component painting to
196 * @param g Graphics to paint to
197 * @param x X coordinate to paint to
198 * @param y Y coordinate to paint to
199 * @param w Width to paint to
200 * @param h Height to paint to
201 * @param image Image to paint
202 * @param args Arguments supplied to <code>paint</code>
203 */
204 protected void paintImage(Component c, Graphics g,
205 int x, int y, int w, int h, Image image,
206 Object[] args) {
207 g.drawImage(image, x, y, null);
208 }
209
210 /**
211 * Creates the image to cache. This returns an opaque image, subclasses
212 * that require translucency or transparency will need to override this
213 * method.
214 *
215 * @param c Component painting to
216 * @param w Width of image to create
217 * @param h Height to image to create
218 * @param config GraphicsConfiguration that will be
219 * rendered to, this may be null.
220 * @param args Arguments passed to paint
221 */
222 protected Image createImage(Component c, int w, int h,
223 GraphicsConfiguration config, Object[] args) {
224 if (config == null) {
225 return new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
226 }
227 return config.createCompatibleVolatileImage(w, h);
228 }
229
230 /**
231 * Clear the image cache
232 */
233 protected void flush() {
234 synchronized(CachedPainter.class) {
235 getCache(getClass()).flush();
236 }
237 }
238
239 private GraphicsConfiguration getGraphicsConfiguration(Component c) {
240 if (c == null) {
241 return null;
242 }
243 return c.getGraphicsConfiguration();
244 }
245
246 class PainterMultiResolutionCachedImage extends AbstractMultiResolutionImage {
247
248 private final int baseWidth;
249 private final int baseHeight;
250 private Component c;
251 private Object[] args;
252
253 public PainterMultiResolutionCachedImage(int baseWidth, int baseHeight) {
254 this.baseWidth = baseWidth;
255 this.baseHeight = baseHeight;
256 }
257
258 public void setParams(Component c, Object[] args) {
259 this.c = c;
260 this.args = args;
261 }
262
263 @Override
264 public int getWidth(ImageObserver observer) {
265 return baseWidth;
266 }
267
268 @Override
269 public int getHeight(ImageObserver observer) {
270 return baseHeight;
271 }
272
273 @Override
274 public Image getResolutionVariant(double destWidth, double destHeight) {
275 int w = (int) Math.ceil(destWidth);
276 int h = (int) Math.ceil(destHeight);
277 return getImage(PainterMultiResolutionCachedImage.class,
278 c, baseWidth, baseHeight, w, h, args);
279 }
280
281 @Override
282 protected Image getBaseImage() {
283 return getResolutionVariant(baseWidth, baseHeight);
284 }
285
286 @Override
287 public java.util.List<Image> getResolutionVariants() {
288 return Arrays.asList(getResolutionVariant(baseWidth, baseHeight));
289 }
290 }
291 }