fop/src/java/org/apache/fop/fonts/SingleByteFont.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.fonts;

import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Generic SingleByte font
 */
public class SingleByteFont extends CustomFont {

    /** logger */
    private  static Log log = LogFactory.getLog(SingleByteFont.class);

    private SingleByteEncoding mapping;

    private int[] width = null;

    private Map unencodedCharacters;
    //Map<Character, UnencodedCharacter>
    private List additionalEncodings;
    
    /**
     * Main constructor.
     */
    public SingleByteFont() {
        setEncoding(CodePointMapping.WIN_ANSI_ENCODING);
    }
    
    /** {@inheritDoc} */
    public boolean isEmbeddable() {
        return (!(getEmbedFileName() == null 
                && getEmbedResourceName() == null));
    }

    /** {@inheritDoc} */
    public String getEncodingName() {
        return this.mapping.getName();
    }

    /**
     * Returns the code point mapping (encoding) of this font.
     * @return the code point mapping
     */
    public SingleByteEncoding getEncoding() {
        return this.mapping;
    }
    
    /** {@inheritDoc} */
    public int getWidth(int i, int size) {
        if (i < 256) {
            int idx = i - getFirstChar();
            if (idx >= 0 && idx < width.length) {
                return size * width[i - getFirstChar()];
            }
        } else if (this.additionalEncodings != null) {
            int encodingIndex = (i / 256) - 1;
            SimpleSingleByteEncoding encoding = getAdditionalEncoding(encodingIndex);
            int codePoint = i % 256;
            NamedCharacter nc = encoding.getCharacterForIndex(codePoint);
            UnencodedCharacter uc
                = (UnencodedCharacter)this.unencodedCharacters.get(
                        new Character(nc.getSingleUnicodeValue()));
            return size * uc.getWidth();
        }
        return 0;
    }

    /** {@inheritDoc} */
    public int[] getWidths() {
        int[] arr = new int[width.length];
        System.arraycopy(width, 0, arr, 0, width.length - 1);
        return arr;
    }

    /** {@inheritDoc} */
    public char mapChar(char c) {
        notifyMapOperation();
        char d = mapping.mapChar(c);
        if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            return d;
        }
        
        //Check unencoded characters which are available in the font by character name
        d = mapUnencodedChar(c);
        if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            return d;
        }
        this.warnMissingGlyph(c);
        return Typeface.NOT_FOUND;
    }

    private char mapUnencodedChar(char ch) {
        if (this.unencodedCharacters != null) {
            UnencodedCharacter unencoded
                = (UnencodedCharacter)this.unencodedCharacters.get(new Character(ch));
            if (unencoded != null) {
                if (this.additionalEncodings == null) {
                    this.additionalEncodings = new java.util.ArrayList();
                }
                SimpleSingleByteEncoding encoding = null;
                char mappedStart = 0;
                int additionalsCount = this.additionalEncodings.size(); 
                for (int i = 0; i < additionalsCount; i++) {
                    mappedStart += 256;
                    encoding = getAdditionalEncoding(i);
                    char alt = encoding.mapChar(ch);
                    if (alt != 0) {
                        return (char)(mappedStart + alt);
                    }
                }
                if (encoding != null && encoding.isFull()) {
                    encoding = null;
                }
                if (encoding == null) {
                    encoding = new SimpleSingleByteEncoding(
                            getFontName() + "EncodingSupp" + (additionalsCount + 1));
                    this.additionalEncodings.add(encoding);
                    mappedStart += 256;
                }
                return (char)(mappedStart + encoding.addCharacter(unencoded.getCharacter()));
            }
        }
        return 0;
    }

    /** {@inheritDoc} */
    public boolean hasChar(char c) {
        char d = mapping.mapChar(c);
        if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            return true;
        }
        //Check unencoded characters which are available in the font by character name
        d = mapUnencodedChar(c);
        if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            return true;
        }
        return false;
    }

    /* ---- single byte font specific setters --- */

    /**
     * Updates the mapping variable based on the encoding.
     * @param encoding the name of the encoding
     */
    protected void updateMapping(String encoding) {
        try {
            this.mapping = CodePointMapping.getMapping(encoding);
        } catch (UnsupportedOperationException e) {
            log.error("Font '" + super.getFontName() + "': " + e.getMessage());
        }
    }
    
    /**
     * Sets the encoding of the font.
     * @param encoding the encoding (ex. "WinAnsiEncoding" or "SymbolEncoding")
     */
    public void setEncoding(String encoding) {
        updateMapping(encoding);
    }
    
    /**
     * Sets the encoding of the font.
     * @param encoding the encoding information
     */
    public void setEncoding(CodePointMapping encoding) {
        this.mapping = encoding;
    }

    /**
     * Sets a width for a character.
     * @param index index of the character
     * @param w the width of the character
     */
    public void setWidth(int index, int w) {
        if (this.width == null) {
            this.width = new int[getLastChar() - getFirstChar() + 1];
        }
        this.width[index - getFirstChar()] = w;
    }

    /**
     * Adds an unencoded character (one that is not supported by the primary encoding).
     * @param ch the named character
     * @param width the width of the character
     */
    public void addUnencodedCharacter(NamedCharacter ch, int width) {
        if (this.unencodedCharacters == null) {
            this.unencodedCharacters = new java.util.HashMap();
        }
        if (ch.hasSingleUnicodeValue()) {
            UnencodedCharacter uc = new UnencodedCharacter(ch, width);
            this.unencodedCharacters.put(new Character(ch.getSingleUnicodeValue()), uc);
        } else {
            //Cannot deal with unicode sequences, so ignore this character
        }
    }

    /**
     * Indicates whether the encoding has additional encodings besides the primary encoding.
     * @return true if there are additional encodings.
     */
    public boolean hasAdditionalEncodings() {
        return (this.additionalEncodings != null) && (this.additionalEncodings.size() > 0);
    }
    
    /**
     * Returns the number of additional encodings this single-byte font maintains.
     * @return the number of additional encodings
     */
    public int getAdditionalEncodingCount() {
        if (hasAdditionalEncodings()) {
            return this.additionalEncodings.size();
        } else {
            return 0;
        }
    }
    
    /**
     * Returns an additional encoding.
     * @param index the index of the additional encoding
     * @return the additional encoding
     * @throws IndexOutOfBoundsException if the index is out of bounds
     */
    public SimpleSingleByteEncoding getAdditionalEncoding(int index)
            throws IndexOutOfBoundsException {
        if (hasAdditionalEncodings()) {
            return (SimpleSingleByteEncoding)this.additionalEncodings.get(index);
        } else {
            throw new IndexOutOfBoundsException("No additional encodings available");
        }
    }
    
    /**
     * Returns an array with the widths for an additional encoding.
     * @param index the index of the additional encoding
     * @return the width array
     */
    public int[] getAdditionalWidths(int index) {
        SimpleSingleByteEncoding enc = getAdditionalEncoding(index);
        int[] arr = new int[enc.getLastChar() - enc.getFirstChar() + 1];
        for (int i = 0, c = arr.length; i < c; i++) {
            NamedCharacter nc = enc.getCharacterForIndex(enc.getFirstChar() + i);
            UnencodedCharacter uc = (UnencodedCharacter)this.unencodedCharacters.get(
                    new Character(nc.getSingleUnicodeValue()));
            arr[i] = uc.getWidth();
        }
        return arr;
    }
    
    private static final class UnencodedCharacter {
        
        private NamedCharacter character;
        private int width;
        
        public UnencodedCharacter(NamedCharacter character, int width) {
            this.character = character;
            this.width = width;
        }
        
        public NamedCharacter getCharacter() {
            return this.character;
        }
        
        public int getWidth() {
            return this.width;
        }
        
        /** {@inheritDoc} */
        public String toString() {
            return getCharacter().toString();
        }
    }

}