Java example source code file (XbmImageDecoder.java)

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Java - Java tags/keywords

awt, bufferedinputstream, image, imageformatexception, indexcolormodel, ioexception, not, xbmcolormap, xbmhints, xbmimagedecoder

The XbmImageDecoder.java Java example source code

/*
 * Copyright (c) 1995, 2003, 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.
 */

/*-
 *      Reads xbitmap format images into a DIBitmap structure.
 */
package sun.awt.image;

import java.io.*;
import java.awt.image.*;

/**
 * Parse files of the form:
 *
 * #define foo_width w
 * #define foo_height h
 * static char foo_bits[] = {
 * 0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,
 * 0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,0xnn,
 * 0xnn,0xnn,0xnn,0xnn};
 *
 * @author James Gosling
 */
public class XbmImageDecoder extends ImageDecoder {
    private static byte XbmColormap[] = {(byte) 255, (byte) 255, (byte) 255,
                                         0, 0, 0};
    private static int XbmHints = (ImageConsumer.TOPDOWNLEFTRIGHT |
                                   ImageConsumer.COMPLETESCANLINES |
                                   ImageConsumer.SINGLEPASS |
                                   ImageConsumer.SINGLEFRAME);

    public XbmImageDecoder(InputStreamImageSource src, InputStream is) {
        super(src, is);
        if (!(input instanceof BufferedInputStream)) {
            // If the topmost stream is a metered stream,
            // we take forever to decode the image...
            input = new BufferedInputStream(input, 80);
        }
    }


    /**
     * An error has occurred. Throw an exception.
     */
    private static void error(String s1) throws ImageFormatException {
        throw new ImageFormatException(s1);
    }

    /**
     * produce an image from the stream.
     */
    public void produceImage() throws IOException, ImageFormatException {
        char nm[] = new char[80];
        int c;
        int i = 0;
        int state = 0;
        int H = 0;
        int W = 0;
        int x = 0;
        int y = 0;
        boolean start = true;
        byte raster[] = null;
        IndexColorModel model = null;
        while (!aborted && (c = input.read()) != -1) {
            if ('a' <= c && c <= 'z' ||
                    'A' <= c && c <= 'Z' ||
                    '0' <= c && c <= '9' || c == '#' || c == '_') {
                if (i < 78)
                    nm[i++] = (char) c;
            } else if (i > 0) {
                int nc = i;
                i = 0;
                if (start) {
                    if (nc != 7 ||
                        nm[0] != '#' ||
                        nm[1] != 'd' ||
                        nm[2] != 'e' ||
                        nm[3] != 'f' ||
                        nm[4] != 'i' ||
                        nm[5] != 'n' ||
                        nm[6] != 'e')
                    {
                        error("Not an XBM file");
                    }
                    start = false;
                }
                if (nm[nc - 1] == 'h')
                    state = 1;  /* expecting width */
                else if (nm[nc - 1] == 't' && nc > 1 && nm[nc - 2] == 'h')
                    state = 2;  /* expecting height */
                else if (nc > 2 && state < 0 && nm[0] == '0' && nm[1] == 'x') {
                    int n = 0;
                    for (int p = 2; p < nc; p++) {
                        c = nm[p];
                        if ('0' <= c && c <= '9')
                            c = c - '0';
                        else if ('A' <= c && c <= 'Z')
                            c = c - 'A' + 10;
                        else if ('a' <= c && c <= 'z')
                            c = c - 'a' + 10;
                        else
                            c = 0;
                        n = n * 16 + c;
                    }
                    for (int mask = 1; mask <= 0x80; mask <<= 1) {
                        if (x < W) {
                            if ((n & mask) != 0)
                                raster[x] = 1;
                            else
                                raster[x] = 0;
                        }
                        x++;
                    }
                    if (x >= W) {
                        if (setPixels(0, y, W, 1, model, raster, 0, W) <= 0) {
                            return;
                        }
                        x = 0;
                        if (y++ >= H) {
                            break;
                        }
                    }
                } else {
                    int n = 0;
                    for (int p = 0; p < nc; p++)
                        if ('0' <= (c = nm[p]) && c <= '9')
                            n = n * 10 + c - '0';
                        else {
                            n = -1;
                            break;
                        }
                    if (n > 0 && state > 0) {
                        if (state == 1)
                            W = n;
                        else
                            H = n;
                        if (W == 0 || H == 0)
                            state = 0;
                        else {
                            model = new IndexColorModel(8, 2, XbmColormap,
                                                        0, false, 0);
                            setDimensions(W, H);
                            setColorModel(model);
                            setHints(XbmHints);
                            headerComplete();
                            raster = new byte[W];
                            state = -1;
                        }
                    }
                }
            }
        }
        input.close();
        imageComplete(ImageConsumer.STATICIMAGEDONE, true);
    }
}