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

import java.io.IOException;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.font.FontRenderContext;
import java.awt.font.GlyphVector;
import java.awt.font.GlyphMetrics;
import java.awt.geom.Rectangle2D;
import java.awt.Shape;

import org.freehep.graphicsio.font.encoding.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,v 1.2 2002/08/24 00:04:14 duns Exp $
 */
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;
    }
}