fop/src/java/org/apache/fop/afp/goca/GraphicsCharacterString.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id$ */

package org.apache.fop.afp.goca;

import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

import org.apache.fop.afp.AFPConstants;

/**
 * A GOCA graphics string
 */
public class GraphicsCharacterString extends AbstractGraphicsCoord {

    /** Up to 255 bytes of character data */
    protected static final int MAX_STR_LEN = 255;

    /** the string to draw */
    protected final String str;

    /**
     * Constructor (absolute positioning)
     *
     * @param str the character string
     * @param x the x coordinate
     * @param y the y coordinate
     */
    public GraphicsCharacterString(String str, int x, int y) {
        super(x, y);
        this.str = truncate(str);
    }

    /**
     * Constructor (relative positioning)
     *
     * @param str the character string
     * @param x the x coordinate
     * @param y the y coordinate
     */
    public GraphicsCharacterString(String str) {
        super(null);
        this.str = truncate(str);
    }

    /** {@inheritDoc} */
    byte getOrderCode() {
        if (isRelative()) {
            return (byte)0x83;
        } else {
            return (byte)0xC3;
        }
    }

    /** {@inheritDoc} */
    public int getDataLength() {
        return super.getDataLength() + str.length();
    }

    /** {@inheritDoc} */
    public void writeToStream(OutputStream os) throws IOException {
        byte[] data = getData();
        byte[] strData = getStringAsBytes();
        System.arraycopy(strData, 0, data, 6, strData.length);
        os.write(data);
    }

    /**
     * Truncates the string as necessary
     *
     * @param str a character string
     * @return a possibly truncated string
     */
    private String truncate(String str) {
        if (str.length() > MAX_STR_LEN) {
            str = str.substring(0, MAX_STR_LEN);
            log.warn("truncated character string, longer than " + MAX_STR_LEN + " chars");
        }
        return str;
    }

    /**
     * Returns the text string as an encoded byte array
     *
     * @return the text string as an encoded byte array
     */
    private byte[] getStringAsBytes() throws UnsupportedEncodingException {
        return str.getBytes(AFPConstants.EBCIDIC_ENCODING);
    }

    /** {@inheritDoc} */
    public String toString() {
        return "GraphicsCharacterString{"
            + (coords != null ? "x=" + coords[0] + ", y=" + coords[1] : "")
            + "str='" + str + "'" + "}";
    }
}