/*
 * [Broadcaster.java]
 *
 * Summary: Broadcasts changed country to other applets on the page. Runs in a separate thread.
 *
 * 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:
 *  3.5 2008-09-19 allow commas in parameter amount values.
 */
package com.mindprod.currcon;

import java.applet.Applet;
import java.applet.AppletContext;
import java.util.Enumeration;

import static java.lang.System.*;

/**
 * Broadcasts changed country to other applets on the page. Runs in a separate thread.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 3.5 2008-09-19 allow commas in parameter amount values.
 * @since 2001
 */
class Broadcaster implements Runnable
    {
    /**
     * instance of CurrCon Applet that first noticed the change.
     */
    private final CurrCon self;

    /**
     * new currency index we broadcast
     */
    private final int currentCurrIndex;

    /**
     * constructor
     *
     * @param currentCurrIndex New currency index, 0..N, e.g. dollars, pounds..
     * @param self             Applet instance doing the broadcasting.
     */
    Broadcaster( CurrCon self, final int currentCurrIndex )
        {
        this.self = self;
        this.currentCurrIndex = currentCurrIndex;
        }

    /**
     * broadcast to all CurrCon Applets on this page, including ourself.
     * Runs on a background thread to notify all other Applets.
     */
    public void run()
        {
        // We have to get everyone to notice currentCurrIndex has changed, and
        // recalculate their amounts.
        final AppletContext ac = self.getAppletContext();
        if ( ac != null )
            {
            // all Applets on page, possibly including us, including non-CurrCon
            final Enumeration<Applet> otherApplets = ac.getApplets();
            if ( otherApplets == null || !otherApplets.hasMoreElements() )
                {
                if ( CurrCon.DEBUGGING )
                    {
                    out.println( self.getInstance() + " sees no other Applets" );
                    }
                }
            else
                {
                while ( otherApplets.hasMoreElements() )
                    {
                    // Broadcast to all other Applets. List may or may not include ourself.
                    // Exclude ourself just in case
                    final Object otherApplet = otherApplets.nextElement();
                    if ( otherApplet instanceof CurrCon && otherApplet != self )
                        {
                        if ( CurrCon.DEBUGGING )
                            {
                            out.println( self.getInstance() + " notifying " + ( ( CurrCon ) otherApplet ).getInstance() );
                            }
                        // other instances will use our thread to update the screen
                        ( ( CurrCon ) otherApplet ).currencyChangeListener( currentCurrIndex );
                        }
                    else
                        {
                        if ( CurrCon.DEBUGGING )
                            {
                            out.println( self.getInstance() + " seeing an applet that does not need notifying" );
                            }
                        }
                    } // end while
                }
            }
        } // end run
    }