XbmImageDecoder.java

/*
 * 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);
    }
}