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src/java.desktop/share/classes/sun/swing/CachedPainter.java

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   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


  82      * <code>paintImage</code> is invoked to paint the cached image.
  83      *
  84      * @param c Component rendering to, this may be null.
  85      * @param g Graphics to paint to
  86      * @param x X-coordinate to render to
  87      * @param y Y-coordinate to render to
  88      * @param w Width to render in
  89      * @param h Height to render in
  90      * @param args Variable arguments that will be passed to paintToImage
  91      */
  92     public void paint(Component c, Graphics g, int x,
  93                          int y, int w, int h, Object... args) {
  94         if (w <= 0 || h <= 0) {
  95             return;
  96         }
  97         synchronized (CachedPainter.class) {
  98             paint0(c, g, x, y, w, h, args);
  99         }
 100     }
 101 
 102     private void paint0(Component c, Graphics g, int x,
 103                          int y, int w, int h, Object... args) {
 104         Object key = getClass();
 105         GraphicsConfiguration config = getGraphicsConfiguration(c);
 106         ImageCache cache = getCache(key);
 107         Image image = cache.getImage(key, config, w, h, args);
 108         int attempts = 0;
 109         do {
 110             boolean draw = false;
 111             if (image instanceof VolatileImage) {
 112                 // See if we need to recreate the image
 113                 switch (((VolatileImage)image).validate(config)) {
 114                 case VolatileImage.IMAGE_INCOMPATIBLE:
 115                     ((VolatileImage)image).flush();
 116                     image = null;
 117                     break;
 118                 case VolatileImage.IMAGE_RESTORED:
 119                     draw = true;
 120                     break;
 121                 }
 122             }
 123             if (image == null) {
 124                 // Recreate the image
 125                 image = createImage(c, w, h, config, args);
 126                 cache.setImage(key, config, w, h, args, image);
 127                 draw = true;
 128             }
 129             if (draw) {
 130                 // Render to the Image
 131                 Graphics g2 = image.getGraphics();
 132                 paintToImage(c, image, g2, w, h, args);
 133                 g2.dispose();
 134             }
 135 
 136             // Render to the passed in Graphics
 137             paintImage(c, g, x, y, w, h, image, args);
 138 
 139             // If we did this 3 times and the contents are still lost
 140             // assume we're painting to a VolatileImage that is bogus and
 141             // give up.  Presumably we'll be called again to paint.
 142         } while ((image instanceof VolatileImage) &&
 143                  ((VolatileImage)image).contentsLost() && ++attempts < 3);





























 144     }
 145 
 146     /**
 147      * Paints the representation to cache to the supplied Graphics.
 148      *
 149      * @param c Component painting to, may be null.
 150      * @param image Image to paint to
 151      * @param g Graphics to paint to, obtained from the passed in Image.
 152      * @param w Width to paint to
 153      * @param h Height to paint to
 154      * @param args Arguments supplied to <code>paint</code>
 155      */
 156     protected abstract void paintToImage(Component c, Image image, Graphics g,
 157                                          int w, int h, Object[] args);
 158 
 159 
 160     /**
 161      * Paints the image to the specified location.
 162      *
 163      * @param c Component painting to


 193             return new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
 194         }
 195         return config.createCompatibleVolatileImage(w, h);
 196     }
 197 
 198     /**
 199      * Clear the image cache
 200      */
 201     protected void flush() {
 202         synchronized(CachedPainter.class) {
 203             getCache(getClass()).flush();
 204         }
 205     }
 206 
 207     private GraphicsConfiguration getGraphicsConfiguration(Component c) {
 208         if (c == null) {
 209             return null;
 210         }
 211         return c.getGraphicsConfiguration();
 212     }


























































 213 }


   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.geom.AffineTransform;
  29 import java.awt.image.*;
  30 import java.util.*;
  31 
  32 /**
  33  * A base class used for icons or images that are expensive to paint.
  34  * A subclass will do the following:
  35  * <ol>
  36  * <li>Invoke <code>paint</code> when you want to paint the image,
  37  *     if you are implementing <code>Icon</code> you'll invoke this from
  38  *     <code>paintIcon</code>.
  39  *     The args argument is useful when additional state is needed.
  40  * <li>Override <code>paintToImage</code> to render the image.  The code that
  41  *     lives here is equivalent to what previously would go in
  42  *     <code>paintIcon</code>, for an <code>Icon</code>.
  43  * </ol>
  44  * The two ways to use this class are:
  45  * <ol>
  46  * <li>Invoke <code>paint</code> to draw the cached reprensentation at
  47  *     the specified location.
  48  * <li>Invoke <code>getImage</code> to get the cached reprensentation and


  83      * <code>paintImage</code> is invoked to paint the cached image.
  84      *
  85      * @param c Component rendering to, this may be null.
  86      * @param g Graphics to paint to
  87      * @param x X-coordinate to render to
  88      * @param y Y-coordinate to render to
  89      * @param w Width to render in
  90      * @param h Height to render in
  91      * @param args Variable arguments that will be passed to paintToImage
  92      */
  93     public void paint(Component c, Graphics g, int x,
  94                          int y, int w, int h, Object... args) {
  95         if (w <= 0 || h <= 0) {
  96             return;
  97         }
  98         synchronized (CachedPainter.class) {
  99             paint0(c, g, x, y, w, h, args);
 100         }
 101     }
 102 
 103     private Image getImage(Object key, Component c, int w, int h, Object... args) {


 104         GraphicsConfiguration config = getGraphicsConfiguration(c);
 105         ImageCache cache = getCache(key);
 106         Image image = cache.getImage(key, config, w, h, args);
 107         int attempts = 0;
 108         do {
 109             boolean draw = false;
 110             if (image instanceof VolatileImage) {
 111                 // See if we need to recreate the image
 112                 switch (((VolatileImage)image).validate(config)) {
 113                 case VolatileImage.IMAGE_INCOMPATIBLE:
 114                     ((VolatileImage)image).flush();
 115                     image = null;
 116                     break;
 117                 case VolatileImage.IMAGE_RESTORED:
 118                     draw = true;
 119                     break;
 120                 }
 121             }
 122             if (image == null) {
 123                 // Recreate the image
 124                 image = createImage(c, w, h, config, args);
 125                 cache.setImage(key, config, w, h, args, image);
 126                 draw = true;
 127             }
 128             if (draw) {
 129                 // Render to the Image
 130                 Graphics g2 = image.getGraphics();
 131                 paintToImage(c, image, g2, w, h, args);
 132                 g2.dispose();
 133             }
 134 



 135             // If we did this 3 times and the contents are still lost
 136             // assume we're painting to a VolatileImage that is bogus and
 137             // give up.  Presumably we'll be called again to paint.
 138         } while ((image instanceof VolatileImage) &&
 139                  ((VolatileImage)image).contentsLost() && ++attempts < 3);
 140 
 141         return image;
 142     }
 143 
 144     private void paint0(Component c, Graphics g, int x,
 145                         int y, int w, int h, Object... args) {
 146         Object key = getClass();
 147         GraphicsConfiguration config = getGraphicsConfiguration(c);
 148         ImageCache cache = getCache(key);
 149         Image image = cache.getImage(key, config, w, h, args);
 150 
 151         if (image == null) {
 152             double sx = 1;
 153             double sy = 1;
 154             if (g instanceof Graphics2D) {
 155                 AffineTransform tx = ((Graphics2D) g).getTransform();
 156                 sx = tx.getScaleX();
 157                 sy = tx.getScaleY();
 158             }
 159             image = new PainterMultiResolutionCachedImage(sx, sy, w, h);
 160             cache.setImage(key, config, w, h, args, image);
 161         }
 162 
 163         if (image instanceof PainterMultiResolutionCachedImage) {
 164             ((PainterMultiResolutionCachedImage) image).setParams(c, args);
 165         }
 166 
 167         // Render to the passed in Graphics
 168         paintImage(c, g, x, y, w, h, image, args);
 169     }
 170 
 171     /**
 172      * Paints the representation to cache to the supplied Graphics.
 173      *
 174      * @param c Component painting to, may be null.
 175      * @param image Image to paint to
 176      * @param g Graphics to paint to, obtained from the passed in Image.
 177      * @param w Width to paint to
 178      * @param h Height to paint to
 179      * @param args Arguments supplied to <code>paint</code>
 180      */
 181     protected abstract void paintToImage(Component c, Image image, Graphics g,
 182                                          int w, int h, Object[] args);
 183 
 184 
 185     /**
 186      * Paints the image to the specified location.
 187      *
 188      * @param c Component painting to


 218             return new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
 219         }
 220         return config.createCompatibleVolatileImage(w, h);
 221     }
 222 
 223     /**
 224      * Clear the image cache
 225      */
 226     protected void flush() {
 227         synchronized(CachedPainter.class) {
 228             getCache(getClass()).flush();
 229         }
 230     }
 231 
 232     private GraphicsConfiguration getGraphicsConfiguration(Component c) {
 233         if (c == null) {
 234             return null;
 235         }
 236         return c.getGraphicsConfiguration();
 237     }
 238 
 239     class PainterMultiResolutionCachedImage extends AbstractMultiResolutionImage {
 240 
 241         private final double scaleX;
 242         private final double scaleY;
 243         private final int baseWidth;
 244         private final int baseHeight;
 245         private Component c;
 246         private Object[] args;
 247 
 248         public PainterMultiResolutionCachedImage(double scaleX, double scaleY,
 249                                                  int baseWidth, int baseHeight) {
 250             this.scaleX = scaleX;
 251             this.scaleY = scaleY;
 252             this.baseWidth = baseWidth;
 253             this.baseHeight = baseHeight;
 254         }
 255 
 256         public void setParams(Component c, Object[] args) {
 257             this.c = c;
 258             this.args = args;
 259         }
 260 
 261         @Override
 262         public int getWidth(ImageObserver observer) {
 263             return baseWidth;
 264         }
 265 
 266         @Override
 267         public int getHeight(ImageObserver observer) {
 268             return baseHeight;
 269         }
 270 
 271         @Override
 272         public Image getResolutionVariant(double destWidth, double destHeight) {
 273             int w = (int) Math.ceil(destWidth);
 274             int h = (int) Math.ceil(destHeight);
 275             return getImage(this, c, w, h, args);
 276         }
 277 
 278         @Override
 279         protected Image getBaseImage() {
 280             return getResolutionVariant(baseWidth, baseHeight);
 281         }
 282 
 283         @Override
 284         public java.util.List<Image> getResolutionVariants() {
 285 
 286             if (scaleX == 1 && scaleY == 1) {
 287                 return Arrays.asList(getResolutionVariant(baseWidth, baseHeight));
 288             }
 289 
 290             return Arrays.asList(
 291                     getResolutionVariant(baseWidth, baseHeight),
 292                     getResolutionVariant(scaleX * baseWidth, scaleY * baseHeight)
 293             );
 294         }
 295     }
 296 }
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