| /* AlphaComposite.java -- provides a context for performing alpha compositing |
| Copyright (C) 2002, 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.awt; |
| |
| import gnu.java.awt.java2d.AlphaCompositeContext; |
| |
| import java.awt.image.ColorModel; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| |
| /** |
| * |
| * @author Eric Blake (ebb9@email.byu.edu) |
| * @see Composite |
| * @see CompositeContext |
| * @since 1.3 |
| * @status updated to 1.4 except for createContext, needs documentation |
| */ |
| public final class AlphaComposite implements Composite |
| { |
| /** Map Long to AlphaComposites. See getInstance for details. */ |
| private static final LinkedHashMap cache = new LinkedHashMap(11, 0.75f, true) |
| { |
| /** The largest the alpha composite cache can grow. */ |
| private static final int MAX_CACHE_SIZE = 2048; |
| |
| /** Prune stale entries. */ |
| protected boolean removeEldestEntry(Map.Entry eldest) |
| { // XXX - FIXME Use Map.Entry, not just Entry as gcj 3.1 workaround. |
| return size() > MAX_CACHE_SIZE; |
| } |
| }; |
| |
| public static final int CLEAR = 1; |
| public static final int SRC = 2; |
| public static final int DST = 9; |
| public static final int SRC_OVER = 3; |
| public static final int DST_OVER = 4; |
| public static final int SRC_IN = 5; |
| public static final int DST_IN = 6; |
| public static final int SRC_OUT = 7; |
| public static final int DST_OUT = 8; |
| public static final int SRC_ATOP = 10; |
| public static final int DST_ATOP = 11; |
| public static final int XOR = 12; |
| public static final AlphaComposite Clear = getInstance(CLEAR); |
| public static final AlphaComposite Src = getInstance(SRC); |
| public static final AlphaComposite Dst = getInstance(DST); |
| public static final AlphaComposite SrcOver = getInstance(SRC_OVER); |
| public static final AlphaComposite DstOver = getInstance(DST_OVER); |
| public static final AlphaComposite SrcIn = getInstance(SRC_IN); |
| public static final AlphaComposite DstIn = getInstance(DST_IN); |
| public static final AlphaComposite SrcOut = getInstance(SRC_OUT); |
| public static final AlphaComposite DstOut = getInstance(DST_OUT); |
| public static final AlphaComposite SrcAtop = getInstance(SRC_ATOP); |
| public static final AlphaComposite DstAtop = getInstance(DST_ATOP); |
| public static final AlphaComposite Xor = getInstance(XOR); |
| |
| private final int rule; |
| private final float alpha; |
| private AlphaComposite(int rule, float alpha) |
| { |
| this.rule = rule; |
| this.alpha = alpha; |
| } |
| |
| /** |
| * Creates an AlphaComposite object with the specified rule. |
| * |
| * @param rule The compositing rule. |
| * |
| * @exception IllegalArgumentException If rule is not one of the following: |
| * CLEAR, SRC, DST, SRC_OVER, DST_OVER, SRC_IN, DST_IN, SRC_OUT, DST_OUT, |
| * SRC_ATOP, DST_ATOP, or XOR. |
| */ |
| public static AlphaComposite getInstance(int rule) |
| { |
| return getInstance(rule, 1); |
| } |
| |
| /** |
| * Creates an AlphaComposite object with the specified rule and the constant |
| * alpha to multiply with the alpha of the source. The source is multiplied |
| * with the specified alpha before being composited with the destination. |
| * |
| * @param rule The compositing rule. |
| * |
| * @exception IllegalArgumentException If rule is not one of the following: |
| * CLEAR, SRC, DST, SRC_OVER, DST_OVER, SRC_IN, DST_IN, SRC_OUT, DST_OUT, |
| * SRC_ATOP, DST_ATOP, or XOR. |
| */ |
| public static AlphaComposite getInstance(int rule, float alpha) |
| { |
| if (rule < CLEAR || rule > XOR || ! (alpha >= 0 && alpha <= 1)) |
| throw new IllegalArgumentException(); |
| // This long is guaranteed unique for all valid alpha composites. |
| Long l = new Long(rule + Double.doubleToLongBits(alpha)); |
| AlphaComposite a = (AlphaComposite) cache.get(l); |
| if (a == null) |
| { |
| a = new AlphaComposite(rule, alpha); |
| cache.put(l, a); |
| } |
| return a; |
| } |
| |
| /** |
| * Creates a {@link CompositeContext} that can be used to perform |
| * compositing operations according to this AlphaComposite settings. |
| * |
| * @param srcColorModel the color model of the source raster |
| * @param dstColorModel the color model of the destination raster |
| * @param hints the rendering hints to use |
| * |
| * @return a {@link CompositeContext} that can be used to perform |
| * compositing operations according to this AlphaComposite settings |
| */ |
| public CompositeContext createContext(ColorModel srcColorModel, |
| ColorModel dstColorModel, |
| RenderingHints hints) |
| { |
| return new AlphaCompositeContext(this, srcColorModel, dstColorModel); |
| } |
| |
| public float getAlpha() |
| { |
| return alpha; |
| } |
| public int getRule() |
| { |
| return rule; |
| } |
| public int hashCode() |
| { |
| return 31 * Float.floatToIntBits(alpha) + rule; |
| } |
| public boolean equals(Object o) |
| { |
| if (! (o instanceof AlphaComposite)) |
| return false; |
| AlphaComposite a = (AlphaComposite) o; |
| return rule == a.rule && alpha == a.alpha; |
| } |
| } // class AlphaComposite |