// Copyright 2001-2005 freehep
package org.freehep.graphicsio.font;

import java.awt.Font;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.io.IOException;

import org.freehep.graphics2d.font.CharTable;

/**
 * Instances of this class write the information into documents (ps or pdf) that
 * is necessary in order to include or embed fonts. In order to guarantee a
 * time-invariant interface the main methods to implement by subclasses
 * <tt>includeFont</tt> takes no arguments. All necessary data should be
 * available by getter methods which can easily be added. <br>
 * The abstract methods are called in the following order:
 * <ul>
 * <li><tt>openIncludeFont</tt>
 * <li><tt>writeEncoding</tt>
 * <li><tt>closeIncludeFont</tt>
 * </ul>
 * 
 * @author Simon Fischer
 * @version $Id: FontIncluder.java 8584 2006-08-10 23:06:37Z duns $
 */
public abstract class FontIncluder {

    public static final double FONT_SIZE = 1000;

    // -------------------- abstract methods --------------------

    /**
     * Writes the given information about the font into the file. When this
     * method is called all <tt>getXXX()</tt> are guaranteed to return
     * reasonable values.
     */
    protected abstract void openIncludeFont() throws IOException;

    /** Writes the encoding table to the file. */
    protected abstract void writeEncoding(CharTable charTable)
            throws IOException;

    /** Does nothing, but can be implemented by subclasses if necessary. */
    protected void closeIncludeFont() throws IOException {
    }

    // -----------------------------------------------------------

    private FontRenderContext context;

    private Rectangle2D fontBBox;

    private Font font;

    private String fontName;

    private CharTable charTable;

    private char[] unicode;

    private String[] charName;

    private int noDefinedChars;

    public FontIncluder(FontRenderContext context) {
        this.context = context;
        this.noDefinedChars = -1;
    }

    // -----------------------------------------------------------

    protected FontRenderContext getContext() {
        return context;
    }

    protected String getFontName() {
        return fontName;
    }

    protected Font getFont() {
        return font;
    }

    protected CharTable getEncodingTable() {
        return charTable;
    }

    protected Rectangle2D getFontBBox() {
        return fontBBox;
    }

    protected String getCharName(int i) {
        return charName[i];
    }

    protected char getUnicode(int i) {
        return unicode[i];
    }

    protected char[] getUnicode() {
        return unicode;
    }

    protected int getNODefinedChars() {
        return noDefinedChars;
    }

    // -----------------------------------------------------------

    /**
     * Embed this font to the file.
     * 
     * @param font The font to include
     * @param name The name under which this font is addressed within the
     *        document (can be retrieved by <tt>getFontName()</tt>)
     */
    public void includeFont(Font font, CharTable charTable, String name)
            throws IOException {

        unicode = null;
        charName = null;

        this.font = font;
        this.charTable = charTable;
        this.fontName = name;

        // figure out the maximum bounding box for all characters
        this.fontBBox = font.getMaxCharBounds(context);

        // figure out the unicodes and character names and
        // create a glyph vector containing the 256 glyphs of the font
        this.noDefinedChars = 0;
        this.unicode = new char[256];
        this.charName = new String[256];
        for (int i = 0; i < unicode.length; i++) {
            charName[i] = charTable.toName(i);
            if (charName[i] != null) {
                unicode[i] = charTable.toUnicode(charName[i]);
                noDefinedChars++;
            } else {
                unicode[i] = 0;
            }
        }

        openIncludeFont();
        writeEncoding(charTable);
        closeIncludeFont();
    }

    protected double getUndefinedWidth() {
        return FONT_SIZE;
    }
}