poi/src/java/org/apache/poi/hssf/usermodel/FontDetails.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.
==================================================================== */

package org.apache.poi.hssf.usermodel;

import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.StringTokenizer;

/**
 * Stores width and height details about a font.
 */
public class FontDetails
{
    private String _fontName;
    private int _height;
    private final Map<Character, Integer> charWidths = new HashMap<>();

    /**
     * Construct the font details with the given name and height.
     *
     * @param fontName  The font name.
     * @param height    The height of the font.
     */
    public FontDetails( String fontName, int height )
    {
        _fontName = fontName;
        _height = height;
    }

    public String getFontName()
    {
        return _fontName;
    }

    public int getHeight()
    {
        return _height;
    }

    public void addChar( char c, int width )
    {
        charWidths.put(Character.valueOf(c), Integer.valueOf(width));
    }

    /**
     * Retrieves the width of the specified character.  If the metrics for
     * a particular character are not available it defaults to returning the
     * width for the 'W' character.
     */
    public int getCharWidth( char c )
    {
        Integer widthInteger = charWidths.get(Character.valueOf(c));
        if (widthInteger == null) {
            return 'W' == c ? 0 : getCharWidth('W');
        }
        return widthInteger;
    }

    public void addChars( char[] characters, int[] widths )
    {
        for ( int i = 0; i < characters.length; i++ )
        {
            charWidths.put( Character.valueOf(characters[i]), Integer.valueOf(widths[i]));
        }
    }

    protected static String buildFontHeightProperty(String fontName) {
        return "font." + fontName + ".height";
    }
    protected static String buildFontWidthsProperty(String fontName) {
        return "font." + fontName + ".widths";
    }
    protected static String buildFontCharactersProperty(String fontName) {
        return "font." + fontName + ".characters";
    }

    /**
     * Create an instance of <code>FontDetails</code> by loading them from the
     * provided property object.
     * @param fontName          the font name
     * @param fontMetricsProps  the property object holding the details of this
     *                          particular font.
     * @return  a new FontDetails instance.
     */
    public static FontDetails create( String fontName, Properties fontMetricsProps )
    {
        String heightStr = fontMetricsProps.getProperty( buildFontHeightProperty(fontName) );
        String widthsStr = fontMetricsProps.getProperty( buildFontWidthsProperty(fontName) );
        String charactersStr = fontMetricsProps.getProperty( buildFontCharactersProperty(fontName) );

        // Ensure that this is a font we know about
        if(heightStr == null || widthsStr == null || charactersStr == null) {
            // We don't know all we need to about this font
            // Since we don't know its sizes, we can't work with it
            throw new IllegalArgumentException("The supplied FontMetrics doesn't know about the font '" + fontName + "', so we can't use it. Please add it to your font metrics file (see StaticFontMetrics.getFontDetails");
        }

        int height = Integer.parseInt(heightStr);
        FontDetails d = new FontDetails(fontName, height);
        String[] charactersStrArray = split(charactersStr, ",", -1);
        String[] widthsStrArray = split(widthsStr, ",", -1);
        if (charactersStrArray.length != widthsStrArray.length)
            throw new RuntimeException("Number of characters does not number of widths for font " + fontName);
        for ( int i = 0; i < widthsStrArray.length; i++ )
        {
            if (charactersStrArray[i].length() != 0)
                d.addChar(charactersStrArray[i].charAt(0), Integer.parseInt(widthsStrArray[i]));
        }
        return d;
    }

    /**
     * Gets the width of all characters in a string.
     *
     * @param str   The string to measure.
     * @return      The width of the string for a 10 point font.
     */
    public int getStringWidth(String str)
    {
        int width = 0;
        for (int i = 0; i < str.length(); i++)
        {
            width += getCharWidth(str.charAt(i));
        }
        return width;
    }

    /**
     * Split the given string into an array of strings using the given
     * delimiter.
     */
    private static String[] split(String text, String separator, int max)
    {
        StringTokenizer tok = new StringTokenizer(text, separator);
        int listSize = tok.countTokens();
        if(max != -1 && listSize > max)
            listSize = max;
        String[] list = new String[listSize];
        for(int i = 0; tok.hasMoreTokens(); i++)
        {
            if(max != -1 && i == listSize - 1)
            {
                StringBuilder buf = new StringBuilder((text.length() * (listSize - i)) / listSize);
                while(tok.hasMoreTokens())
                {
                    buf.append(tok.nextToken());
                    if(tok.hasMoreTokens())
                        buf.append(separator);
                }
                list[i] = buf.toString().trim();
                break;
            }
            list[i] = tok.nextToken().trim();
        }

        return list;
    }
}