/*==================================================*
 $Id: slideshow.js,v 1.16 2003/10/14 12:39:00 pat Exp $
 Copyright 2000-2003 Patrick Fitzgerald
 http://slideshow.barelyfitz.com/
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *==================================================*/
// There are two objects defined in this file:
// "slide" - contains all the information for a single slide
// "slideshow" - consists of multiple slide objects and runs the slideshow

//==================================================
// slide object
//==================================================
function slide(src, link, text, target, attr){
    this.src = src;
    this.link = link;
    this.text = text;
    this.target = target;
    this.attr = attr;
    if (document.images) {
        this.image = new Image();
    }
    this.loaded = false;
    this.load = function(){
        if (!document.images) {
            return;
        }
        if (!this.loaded) {
            this.image.src = this.src;
            this.loaded = true;
        }
    }
    
    this.hotlink = function(){
        var mywindow;
        if (!this.link) 
            return;
        if (this.target) {
            if (this.attr) {
                mywindow = window.open(this.link, this.target, this.attr);
            }
            else {
                mywindow = window.open(this.link, this.target);
            }
            if (mywindow && mywindow.focus) 
                mywindow.focus();
        }
        else {
            location.href = this.link;
        }
    }
}

function slideshow(slideshowname){
    this.name = slideshowname;
    this.repeat = true;
    this.prefetch = 0;
    this.image;
    this.textid;
    this.textarea;
    this.timeout = 3000;
    this.slides = new Array();
    this.current = 0;
    this.timeoutid = 0;
    
    this.add_slide = function(slide){
        var i = this.slides.length;
        if (this.prefetch == -1) {
            slide.load();
        }
        this.slides[i] = slide;
    }
    
    this.play = function(timeout){
        this.pause();
        if (timeout) {
            this.timeout = timeout;
        }
        if (typeof this.slides[this.current].timeout != 'undefined') {
            timeout = this.slides[this.current].timeout;
        }
        else {
            timeout = this.timeout;
        }
        this.timeoutid = setTimeout(this.name + ".loop()", timeout);
    }
    
    this.pause = function(){
        if (this.timeoutid != 0) {
            clearTimeout(this.timeoutid);
            this.timeoutid = 0;
        }
    }
    
    this.update = function(){
        if (!this.valid_image()) {
            return;
        }
        if (typeof this.pre_update_hook == 'function') {
            this.pre_update_hook();
        }
        var slide = this.slides[this.current];
        var dofilter = false;
        if (this.image &&
        typeof this.image.filters != 'undefined' &&
        typeof this.image.filters[0] != 'undefined') {
            dofilter = true;
            
        }
        slide.load();
        if (dofilter) {
            if (slide.filter &&
            this.image.style &&
            this.image.style.filter) {
                this.image.style.filter = slide.filter;
            }
            this.image.filters[0].Apply();
        }
        this.image.src = slide.image.src;
        if (dofilter) {
            this.image.filters[0].Play();
        }
        this.display_text();
        if (typeof this.post_update_hook == 'function') {
            this.post_update_hook();
        }
        if (this.prefetch > 0) {
            var next, prev, count;
            next = this.current;
            prev = this.current;
            count = 0;
            do {
                if (++next >= this.slides.length) 
                    next = 0;
                if (--prev < 0) 
                    prev = this.slides.length - 1;
                this.slides[next].load();
                this.slides[prev].load();
            }
            while (++count < this.prefetch);
                    }
    }
    
    this.goto_slide = function(n){
        if (n == -1) {
            n = this.slides.length - 1;
        }
        if (n < this.slides.length && n >= 0) {
            this.current = n;
        }
        this.update();
    }
    
    
    this.goto_random_slide = function(include_current){
        var i;
        if (this.slides.length > 1) {
            do {
                i = Math.floor(Math.random() * this.slides.length);
            }
            while (i == this.current);
            this.goto_slide(i);
        }
    }
    
    
    this.next = function(){
        if (this.current < this.slides.length - 1) {
            this.current++;
        }
        else 
            if (this.repeat) {
                this.current = 0;
            }
        this.update();
    }
    
    this.previous = function(){
        if (this.current > 0) {
            this.current--;
        }
        else 
            if (this.repeat) {
                this.current = this.slides.length - 1;
            }
        this.update();
    }
    
    
    this.shuffle = function(){
        var i, i2, slides_copy, slides_randomized;
        slides_copy = new Array();
        for (i = 0; i < this.slides.length; i++) {
            slides_copy[i] = this.slides[i];
        }
        slides_randomized = new Array();
        do {
            i = Math.floor(Math.random() * slides_copy.length);
            slides_randomized[slides_randomized.length] = slides_copy[i];
            for (i2 = i + 1; i2 < slides_copy.length; i2++) {
                slides_copy[i2 - 1] = slides_copy[i2];
            }
            slides_copy.length--;
        }
        while (slides_copy.length);
        this.slides = slides_randomized;
    }
    
    this.get_text = function(){
        return (this.slides[this.current].text);
    }
    
    this.get_all_text = function(before_slide, after_slide){
        all_text = "";
        for (i = 0; i < this.slides.length; i++) {
            slide = this.slides[i];
            if (slide.text) {
                all_text += before_slide + slide.text + after_slide;
            }
            
        }
        return (all_text);
    }
    
    
    this.display_text = function(text){
        if (!text) {
            text = this.slides[this.current].text;
        }
        if (this.textarea && typeof this.textarea.value != 'undefined') {
            this.textarea.value = text;
        }
        if (this.textid) {
        
            r = this.getElementById(this.textid);
            if (!r) {
                return false;
            }
            if (typeof r.innerHTML == 'undefined') {
                return false;
            }
            r.innerHTML = text;
        }
    }
    
    this.hotlink = function(){
        this.slides[this.current].hotlink();
    }
    
    this.save_position = function(cookiename){
        if (!cookiename) {
            cookiename = this.name + '_slideshow';
        }
        document.cookie = cookiename + '=' + this.current;
    }
    
    this.restore_position = function(cookiename){
        if (!cookiename) {
            cookiename = this.name + '_slideshow';
        }
        
        var search = cookiename + "=";
        
        if (document.cookie.length > 0) {
            offset = document.cookie.indexOf(search);
            if (offset != -1) {
                offset += search.length;
                end = document.cookie.indexOf(";", offset);
                if (end == -1) 
                    end = document.cookie.length;
                this.current = parseInt(unescape(document.cookie.substring(offset, end)));
            }
        }
    }
    
    
    this.noscript = function(){
        $html = "\n";
        
        for (i = 0; i < this.slides.length; i++) {
            slide = this.slides[i];
            $html += '<P>';
            if (slide.link) {
                $html += '<a href="' + slide.link + '">';
            }
            $html += '<img src="' + slide.src + '" ALT="slideshow image">';
            if (slide.link) {
                $html += "<\/a>";
            }
            if (slide.text) {
                $html += "<BR>\n" + slide.text;
            }
            $html += "<\/P>" + "\n\n";
        }
        
        $html = $html.replace(/\&/g, "&amp;");
        $html = $html.replace(/</g, "&lt;");
        $html = $html.replace(/>/g, "&gt;");
        
        return ('<pre>' + $html + '</pre>');
    }
    
    
    this.loop = function(){
        if (this.current < this.slides.length - 1) {
            next_slide = this.slides[this.current + 1];
            if (next_slide.image.complete == null || next_slide.image.complete) {
                this.next();
            }
        }
        else {
            this.next();
        }
        this.play();
    }
    
    this.valid_image = function(){
        if (!this.image) {
            return false;
        }
        else {
            return true;
        }
    }
    
    this.getElementById = function(element_id){
        if (document.getElementById) {
            return document.getElementById(element_id);
        }
        else 
            if (document.all) {
                return document.all[element_id];
            }
            else 
                if (document.layers) {
                    return document.layers[element_id];
                }
                else {
                    return undefined;
                }
    }
}