/*
 * [Go.java]
 *
 * Summary: displays glossary indexes, and allows direct jump to corresponding file.
 *
 * Copyright: (c) 2001-2017 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:
 *  1.0 2001-03-08 initial
 *  1.1 2006-01-01
 *  1.2 2006-03-05 reformat with IntelliJ, add Javadoc
 */
package com.mindprod.go;

import com.mindprod.common18.VersionCheck;

import java.applet.Applet;
import java.awt.Choice;
import java.awt.Color;
import java.awt.event.ItemListener;
import java.io.InputStream;
import java.net.URL;

import static java.lang.System.*;

/**
 * displays glossary indexes, and allows direct jump to corresponding file.
 * <p/>
 * Miniature Applet that the end user interacts with. Uses serialised data list of names and targets. Quick find
 * select human name
 * and jump to corresponding URL. Applet param golist controls where serialised list comes from. param window controls
 * target window. See also com\mindprod\keywords\keywords.java which produces the keyword list.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.2 2006-03-05
 * @since 2001-03-08
 */
public final class Go extends Applet
    {
    private static final int FIRST_COPYRIGHT_YEAR = 2001;

    /**
     * undisplayed copyright notice
     */
    private static final String EMBEDDED_COPYRIGHT =
            "Copyright: (c) 2001-2017 Roedy Green, Canadian Mind Products, http://mindprod.com";

    private static final String RELEASE_DATE = "2006-03-06";

    /**
     * embedded version string.
     */
    private static final String VERSION_STRING = "1.2";

    /**
     * displayed human names of the anchors
     */
    private Choice anchorList;

    /**
     * List of human names to URLs
     */
    private GoList goList;

    /**
     * Called by the browser or Applet viewer to inform
     * this Applet that it is being reclaimed and that it should destroy
     * any resources that it has allocated.
     */
    public void destroy()
        {
        anchorList = null;
        goList = null;
        }

    /**
     * Called by the browser or Applet viewer to inform
     * this Applet that it has been loaded into the system.
     */
    public void init()
        {
        if ( !VersionCheck.isJavaVersionOK( 1, 8, 0, this ) )
            {
            return;
            }
        setBackground( Color.white );
        setLayout( null );
        String membername = getParameter( "golist" );
        if ( membername == null || membername.length() == 0 )
            {
            out.println( "Missing GoList\n" );
            return;
            }
        try
            {
            InputStream is =
                    Go.class.getResourceAsStream( "/com/mindprod/qf/"
                                                  + membername );
            if ( is == null )
                {
                out.println( "Missing GoList \"" + membername + "\" \n" );
                return;
                }
            goList = GoList.getData( is );
            }
        catch ( Exception e )
            {
            out.println( "Missing GoList \""
                         + membername
                         + "\" "
                         + e
                         + "\n" );
            return;
            }
        anchorList = new Choice();
        for ( int i = 0, n = goList.size(); i < n; i++ )
            {
            // use addItem instead of add for 1.1 compatibility.
            anchorList.addItem( goList.getHumanname( i ) );
            }
        anchorList.select( 0 );
        anchorList.setSize( this.getSize() );
        add( anchorList );
        anchorList.addItemListener( new ItemListener()
            {
            public void itemStateChanged( java.awt.event.ItemEvent event )
                {
                try
                    {
                    int index = anchorList.getSelectedIndex();
                    if ( index >= 0 )
                        {
                        // send them off to visit the matching page
                        // won't work unless we are in a browser
                        // e.g. relative to E:\mindprod\jgloss
                        String ref;
                        String target = goList.getTarget( index );
                        if ( target.length() != 0 )
                            {
                            ref = goList.getFilename( index ) + '#' + target;
                            }
                        else
                            {
                            ref = goList.getFilename( index );
                            }
                        java.net.URL url = new URL( getDocumentBase(), ref );
                        String window = getParameter( "window" );
                        if ( window == null || window.length() == 0 )
                            {
                            getAppletContext().showDocument( url );
                            }
                        else
                            {
                            getAppletContext().showDocument( url, window );
                            }
                        }
                    }
                catch ( Exception e )
                    {
                    // don't sweat it if it does not work.
                    }
                }
            } );
        validate();
        this.setVisible( true );// Lights, Camera, Action.
        }
    // has no main method. We want this as tiny as possible.
    }