/*
 * [FontSaver.java]
 *
 * Summary: Conserves RAM and time by reusing Font and Font peer objects.
 *
 * Copyright: (c) 1998-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.1 1998-01-15
 *  1.2 1998-11-10 new address and phone.
 *  1.3 2007-12-19
 *  1.4 2008-01-01 bundle with ANT script, pad, icon.
 */
package com.mindprod.fontsaver;

import com.mindprod.common18.FontFactory;

import java.awt.Font;
import java.util.Hashtable;

/**
 * Conserves RAM and time by reusing Font and Font peer objects.
 * <p/>
 * Instead of saying:
 * Font f = FontFactory.build(&quot;Dialog&quot;, 12, Font.PLAIN);
 * say:
 * Font f = FontSaver.create(&quot;Dialog&quot;, 12, Font.PLAIN);
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.4 2008-01-01 bundle with ANT script, pad, icon.
 * @since 1998
 */
public class FontSaver
    {
    private static final int FIRST_COPYRIGHT_YEAR = 1998;

    /**
     * undisplayed copyright notice
     *
     * @noinspection UnusedDeclaration
     */
    private static final String EMBEDDED_COPYRIGHT =
            "Copyright: (c) 1998-2017 Roedy Green, Canadian Mind Products, http://mindprod.com";

    /**
     * date this version released.
     *
     * @noinspection UnusedDeclaration
     */
    private static final String RELEASE_DATE = "2008-01-01";

    /**
     * embedded version string.
     *
     * @noinspection UnusedDeclaration
     */
    private static final String VERSION_STRING = "1.4";

    /**
     * this was JDK 1.2. No HashMap
     */
    private static Hashtable<FontKey, Font> h;

    /**
     * Works just like the Font Constructor: Creates a new font with the specified name, style and point size.
     *
     * @param name  the font name
     * @param style the constant style used
     * @param size  the point size of the font
     *
     * @return Font from cache or created new if not in cache.
     */
    public static Font create( String name, int style, int size )
        {
        if ( h == null )
            {
            h = new Hashtable<>( 101, .75f );
            }
        // see if we have used that font before
        FontKey fontKey = new FontKey( name, style, size );
        Font prevFont = h.get( fontKey );
        if ( prevFont != null )
            {
            return prevFont;
            }
        // we have not used that font before.  We need to create it.
        Font newFont = FontFactory.build( name, style, size );
        // save a copy in case caller asks for it again.
        // The Hashtable will keep growing to keep all the fonts.
        h.put( fontKey, newFont );
        return newFont;
        } // end create
    // used to store previous Fonts, indexed by FontKeys.
    } // end class FontSaver

/*
 * FontKey is just the name, style and size fields of a font,
 * enough to identify it, a key to find it in a Hashtable.
 */
class FontKey
    {
    /**
     * The logical name of this font.
     */
    private final String name;

    /**
     * The point size of this font.
     */
    private final int size;

    /**
     * The style of the font. This is the sum of the constants PLAIN, BOLD, or ITALIC.
     */
    private final int style;

    /**
     * constructor Creates a new FontKey id object with the specified name, style and point size.
     *
     * @param name  the font name
     * @param style the constant style used
     * @param size  the point size of the font
     */
    public FontKey( String name, int style, int size )
        {
        this.name = name;
        this.style = style;
        this.size = size;
        }

    public boolean equals( Object obj )
        {
        if ( obj instanceof FontKey )
            {
            FontKey fontKey = ( FontKey ) obj;
            return ( size == fontKey.size ) && ( style == fontKey.style ) && name.equals( fontKey.name );
            }
        return false;
        }

    /*
     * Returns a hashcode for this font.
     */
    public int hashCode()
        {
        return name.hashCode() ^ style ^ size;
        }
    } // end class FontKey