fop/src/org/apache/fop/render/awt/FontMetricsMapper.java

/*
 * $Id$
 * Copyright (C) 2001 The Apache Software Foundation. All rights reserved.
 * For details on use and redistribution please refer to the
 * LICENSE file included with these sources.
 */

package org.apache.fop.render.awt;

// FOP
import org.apache.fop.layout.FontInfo;
import org.apache.fop.layout.FontDescriptor;
import org.apache.fop.layout.FontState;

// Java
import java.util.Enumeration;
import java.util.Hashtable;
import java.awt.Graphics2D;
import java.awt.Font;


/**
 * This class implements org.apache.fop.layout.FontMetric and
 * is added to the hash table in FontInfo. It  deferes the
 * actual calculation of the metrics to
 * AWTFontMetrics.  It only keeps the java name and
 * style as member varibles
 */

public class FontMetricsMapper implements org.apache.fop.layout.FontMetric {

    /**
     * The first and last non space-character
     */
    private static final int FIRST_CHAR = 32;
    private static final int LAST_CHAR = 255;

    /**
     * This is a AWTFontMetrics that does the real calculation.
     * It is only one class that dynamically determines the font-size.
     */
    private static AWTFontMetrics metric = null;

    /**
     * The java name of the font.
     * #  Make the family name immutable.
     */
    private final String family;

    /**
     * The java style of the font.
     * #  Make the style immutable.
     */
    private final int style;

    /**
     * Constructs a new Font-metrics.
     * @param family the family name of the font (java value)
     * @param style the java type style value of the font
     * @param parent  an AWT component - this is needed  so
     * that we can get an instance of
     * java.awt.FontMetrics
     */
    public FontMetricsMapper(String family, int style, Graphics2D graphics) {
        this.family = family;
        this.style = style;
        if (metric == null)
            metric = new AWTFontMetrics(graphics);
    }

    /**
     * Determines the font ascent of the Font described by this
     * FontMetrics object
     * @return ascent in milliponts
     */
    public int getAscender(int size) {
        return metric.getAscender(family, style, size);
    }


    /**
     * The size of a capital letter measured from the font's baseline
     */
    public int getCapHeight(int size) {
        return metric.getCapHeight(family, style, size);
    }

    /**
     * Determines the font descent of the Font described by this
     * FontMetrics object
     * @return descent in milliponts
     */
    public int getDescender(int size) {
        return metric.getDescender(family, style, size);
    }

    /**
     * Determines the typical font height of this
     * FontMetrics object
     * @return font height in milliponts
     */
    public int getXHeight(int size) {
        return metric.getXHeight(family, style, size);
    }


    public int getFirstChar() {
        return FIRST_CHAR;
    }

    public int getLastChar() {
        return LAST_CHAR;
    }

    /**
     * return width (in 1/1000ths of point size) of character at
     * code point i.
     */
    public int width(int i, int size) {
        return metric.width(i, family, style, size);
    }


    /**
     * return width (in 1/1000ths of point size) of all character
     */
    public int[] getWidths(int size) {
        return metric.getWidths(family, style, size);
    }

    /**
     * Gets a Font instance  of the Font that this
     * FontMetrics describes in the desired size.
     * @return font with the desired characeristics.
     */
    public Font getFont(int size) {
        return metric.getFont(family, style, size);
    }

}