// Title: Tigra Fader
// URL: http://www.softcomplex.com/products/tigra_fader/
// Version: 1.0 (commented source)
// Date: 07/23/2007
// Notes: This script is free. Visit official site for further details.

function tFader(a_items, a_tpl) {

    // validate parameters and set defaults
    if (!a_items) return alert("items structure is missing");
    if (typeof (a_items) != 'object') return alert("format of the items structure is incorrect");
    if (a_items[a_items.length - 1] == null) return alert("last element of the items structure is undefined");
    if (!a_tpl) a_tpl = [];
    for (var i = 0; i < A_TSLIDEDEFS.length; i += 2)
        if (a_tpl[A_TSLIDEDEFS[i]] == null)
        a_tpl[A_TSLIDEDEFS[i]] = A_TSLIDEDEFS[i + 1];

    // save config parameters in the slider object
    this.a_tpl = a_tpl;
    this.a_items = a_tpl.random ? tslide_randomize(a_items) : a_items;

    // initialize parameters, assign methods	
    this.n_currentSlide = 0;
    this.f_goto = tslide_goto;
    this.f_run = function() { this.b_running = 1; this.f_goto(); };
    this.f_stop = function() { this.b_running = 0; clearTimeout(this.o_timerS); };
    this.f_fadeIn = tslide_fadeIn;
    this.f_fadeOut = tslide_fadeOut;
    this.f_slideOp = tslide_slideOp;

    // register in the global collection	
    if (!window.A_SLIDES)
        window.A_SLIDES = [];
    this.n_id = window.A_SLIDES.length;
    window.A_SLIDES[this.n_id] = this;

    // generate control's HTML
    var s_attributes = ' '
		+ (a_tpl['css'] ? ' class="' + a_tpl['css'] + '"' : '')
		+ (a_tpl['width'] ? ' width="' + a_tpl['width'] + '"' : '')
		+ (a_tpl['height'] ? ' height="' + a_tpl['height'] + '"' : '')
		+ (a_tpl['alt'] ? ' title="' + a_tpl['alt'] + '" alt="' + a_tpl['alt'] + '"' : '');

    this.a_imgRefs = [];
    document.write('<img src="', this.a_items[0][0], '"', s_attributes, ' name="tslide', this.n_id, '_0" />');
    this.a_imgRefs[0] = document.images['tslide' + this.n_id + '_0'];
    this.n_currentSlide = 0;

    // exit on old browsers
    if (!this.a_imgRefs[0] || !this.a_imgRefs[0].style || this.a_imgRefs[0].style.marginLeft == null)
        return;

    for (var i = 1; i < this.a_items.length; i++) {
        document.write('<img src="', this.a_items[i][0], '"', s_attributes, ' name="tslide', this.n_id, '_', i, '" style="position:relative;z-index:-1;filter:alpha(opacity=100);" />');
        this.a_imgRefs[i] = document.images['tslide' + this.n_id + '_' + i];
        this.a_imgRefs[i].style.marginLeft = '-' + this.a_tpl.width + 'px';
        this.f_slideOp(i, 0);
        this.a_imgRefs[i].style.zIndex = 10000+i;
    }

    // calculate transition variables
    this.n_timeDec = Math.round(this.a_tpl['transtime'] * 1e3 / this.a_tpl['steps']);
    this.n_opacDec = Math.round(100 / this.a_tpl['steps']);

    // run this sucker
    this.f_run();
}

function tslide_goto(n_slide, b_now) {

    // cancel any scheduled transitions	
    if (this.o_timerS) {
        clearTimeout(this.o_timerS);
        this.o_timerS = null;
        if (this.n_nextSlide) {
            this.f_slideOp(this.n_nextSlide, 0);
            this.n_nextSlide = null;
        }
    }

    // determine the next slide
    this.n_nextSlide = (n_slide == null ? this.n_currentSlide + 1 : n_slide) % this.a_items.length;

    document.getElementById('imageLink').href = this.a_items[this.n_currentSlide][1]

    if (this.n_nextSlide == this.n_currentSlide) return;

    // schedule transition
    this.o_timerS = setTimeout('A_SLIDES[' + this.n_id + '].f_fade' + (this.n_nextSlide > this.n_currentSlide ? 'In' : 'Out') + '()', (b_now ? 0 : this.a_tpl['slidetime'] * 1e3));
}

function tslide_fadeIn(n_opacity) {
    // new transition
    if (n_opacity == null) {
        n_opacity = 0;
    }
    n_opacity += this.n_opacDec;
    // end of transition
    if (n_opacity > 99) {
        this.f_slideOp(this.n_nextSlide, 99);
        this.f_slideOp(this.n_currentSlide, 0);
        this.n_currentSlide = this.n_nextSlide;
        this.n_nextSlide = null;
        return this.f_run();
    }
    // set transparency
    this.f_slideOp(this.n_nextSlide, n_opacity);

    // cycle
    this.o_timerT = setTimeout('A_SLIDES[' + this.n_id + '].f_fadeIn(' + n_opacity + ')', this.n_timeDec);
}
function tslide_fadeOut(n_opacity) {
    // new transition
    if (n_opacity == null) {
        n_opacity = 99;
        this.f_slideOp(this.n_nextSlide, 99);
    }
    n_opacity -= this.n_opacDec;
    // end of transition
    if (n_opacity < 0) {
        this.f_slideOp(this.n_currentSlide, 0);
        this.n_currentSlide = this.n_nextSlide;
        this.n_nextSlide = null;
        return this.f_run();
    }
    // set transparency
    this.f_slideOp(this.n_currentSlide, n_opacity);

    // cycle
    this.o_timerT = setTimeout('A_SLIDES[' + this.n_id + '].f_fadeOut(' + n_opacity + ')', this.n_timeDec);
}

function tslide_slideOp(n_slide, n_opacity) {
    if (!n_slide) return;
    var e_slide = this.a_imgRefs[n_slide];
    tslide_setOpacity(e_slide, n_opacity);
}

function tslide_randomize(a_source) {
    var n_index,
		a_items = [];
    while (a_source.length) {
        n_index = Math.ceil(Math.random() * a_source.length) - 1;
        a_items[a_items.length] = a_source[n_index];
        a_source[n_index] = a_source[a_source.length - 1];
        a_source.length = a_source.length - 1;
    }
    return a_items;
}

// cross-browser opacity
var s_uaApp = navigator.userAgent.toLowerCase();
if (s_uaApp.indexOf('opera') != -1 || s_uaApp.indexOf('safari') != -1)
    window.tslide_setOpacity = function(e_element, n_opacity) {
        e_element.style.opacity = n_opacity / 100;
    };
else if (s_uaApp.indexOf('gecko') != -1)
    window.tslide_setOpacity = function(e_element, n_opacity) {
        e_element.style.MozOpacity = n_opacity / 100;
    };
else if (s_uaApp.indexOf('msie') != -1)
    window.tslide_setOpacity = function(e_element, n_opacity) {
        try { e_element.filters.alpha.opacity = n_opacity } catch (e) { };
    };
else
    window.tslide_setOpacity = null;

// defaults
var A_TSLIDEDEFS = [
	'steps', 40,
	'css', '',
	'transtime', 0.5,
	'slidetime', 2
];