/*************************************************************************

    This code is from Dynamic Web Coding at dyn-web.com

    Copyright 2001-2010 by Sharon Paine 

    See Terms of Use at www.dyn-web.com/business/terms.php

    regarding conditions under which you may use this code.

    This notice must be retained in the code as is!

    

    Version date: Oct 2010

    supports sequential and random rotation and IE win transition filter

    requires dw_event.js

*************************************************************************/



// props supported: id (required), images(required), speed, path, 

// actions, bRand, bMouse, bTrans, alt, title, captions, captionId

function dw_Rotator(rObj) {

    var imgObj = document.getElementById(rObj.id); 

    if ( !imgObj || !rObj.images ) { return; }

    this.id = rObj.id; this.speed = rObj.speed || 4500; // default speed of rotation

    this.path = rObj.path || ""; this.bRand = rObj.bRand; this.bMouse = rObj.bMouse;

    // uses filters for transition (for ie win only)

    this.bTrans = rObj.bTrans && typeof imgObj.filters != 'undefined';

    this.actions = rObj.actions; this.captions = rObj.captions; this.captionId = rObj.captionId;

    this.title = rObj.title; this.alt = rObj.alt; 

    this.ctr = rObj.num || 0; // getRandom fn sets num

    this.timer = 0; this.imgs = [];

    this.addImages(rObj.images); this._setupLink(imgObj);

    var index = dw_Rotator.col.length; dw_Rotator.col[index] = this;

    this.animString = "dw_Rotator.col[" + index + "]";

}



dw_Rotator.col = []; // hold instances

dw_Rotator.resumeDelay = 400; // onmouseout resume rotation after delay

dw_Rotator.prototype.on_rotate = function() {}



// so instance can be retrieved by id (as well as by looping through col)

dw_Rotator.getInstanceById = function(id) {

    var i, obj;

    for (i=0; obj = dw_Rotator.col[i]; i++) {

        if ( obj.id == id ) { return obj; }

    }

    return null;

}



dw_Rotator.prototype.addImages = function(imgAr) { // preloads images

    var i, img;

    for (i=0; imgAr[i]; i++) {

        img = new Image();

        img.src = this.path + imgAr[i];

        this.imgs[this.imgs.length] = img;

    }

}



// mouse events pause/resume

dw_Rotator.prototype._setupLink = function(imgObj) { 

    if ( imgObj.parentNode && imgObj.parentNode.tagName.toLowerCase() == 'a' ) {

        var parentLink = this.parentLink = imgObj.parentNode;

        if (this.bMouse) {

            dw_Event.add(parentLink, 'mouseover', dw_Rotator.pause);

            dw_Event.add(parentLink, 'mouseout', dw_Rotator.resume);

        }

    }

}



dw_Rotator.prototype.rotate = function() {

    this.clearTimer();

    var imgObj = document.getElementById(this.id);

    if ( this.bRand ) {

        this.setRandomCtr();

    } else {

        if (this.ctr < this.imgs.length-1) this.ctr++;

        else this.ctr = 0;

    }

    if ( this.bTrans ) {

        this.doImageTrans(imgObj);

    } else {

        imgObj.src = this.imgs[this.ctr].src;

    }

    this.swapAlt(imgObj); this.prepAction(); this.showCaption();

    this.on_rotate();

    this.timer = setTimeout( this.animString + ".rotate()", this.speed);

}



dw_Rotator.prototype.setRandomCtr = function() {

    var i = 0, ctr;

    do { 

        ctr = Math.floor( Math.random() * this.imgs.length );

        i++; 

    } while ( ctr == this.ctr && i < 6 )// repeat attempts to get new image, if necessary

    this.ctr = ctr;

}



dw_Rotator.prototype.doImageTrans = function(imgObj) {

    imgObj.style.filter = 'blendTrans(duration=1)';

    if (imgObj.filters.blendTrans) imgObj.filters.blendTrans.Apply();

    imgObj.src = this.imgs[this.ctr].src;

    imgObj.filters.blendTrans.Play(); 

}



dw_Rotator.prototype.swapAlt = function(imgObj) {

    if ( !imgObj.setAttribute ) return;

    if ( this.alt && this.alt[this.ctr] ) {

        imgObj.setAttribute('alt', this.alt[this.ctr]);

    }

    if ( this.title && this.title[this.ctr] ) {

        imgObj.setAttribute('title', this.title[this.ctr]);

    }

}



dw_Rotator.prototype.prepAction = function() {

    if ( this.actions && this.parentLink && this.actions[this.ctr] ) {

        if ( typeof this.actions[this.ctr] == 'string' ) {

            this.parentLink.href = this.actions[this.ctr];

        } else if ( typeof this.actions[this.ctr] == 'function' ) {

            // to execute function when linked image clicked 

            // passes id used to uniquely identify instance  

            // retrieve it using the dw_Rotator.getInstanceById function 

            // so any property of the instance could be obtained for use in the function 

            var id = this.id;

            this.parentLink.href = "javascript: void " + this.actions[this.ctr] + "('" + id + "')";

        } 

    }

}



dw_Rotator.prototype.showCaption = function() {

    if ( this.captions && this.captionId ) {

        var el = document.getElementById( this.captionId );

        if ( el && this.captions[this.ctr] ) {

            el.innerHTML = this.captions[this.ctr];

        }

    }

}



dw_Rotator.prototype.clearTimer = function() {

    clearTimeout( this.timer ); this.timer = null;

}



/////////////////////////////////////////////////////////////////////

// class methods



// Start rotation for all instances 

dw_Rotator.start = function(delay) {

    var i, obj;

    for (i=0; obj = dw_Rotator.col[i]; i++) {

        if ( !obj.isActive ) {

            obj.clearTimer(); obj.isActive = true; 

            delay = delay || obj.speed; // passed from restart (aux file)

            obj.timer = setTimeout( obj.animString + ".rotate()", delay);

        }

    }

}



// Stop rotation for all instances 

dw_Rotator.stop = function() {

    var i, obj;

    for (i=0; obj = dw_Rotator.col[i]; i++) {

        obj.clearTimer(); obj.isActive = false;

    }

}



// for stopping/starting (onmouseover/out)

dw_Rotator.pause = function(e) {	

    e = dw_Event.DOMit(e);

    var id = e.target.id;

    var obj = dw_Rotator.getInstanceById(id);

    if (obj) { obj.clearTimer(); }

}



dw_Rotator.resume = function(e) {

    e = dw_Event.DOMit(e);

    var id = e.target.id;

    var obj = dw_Rotator.getInstanceById(id);

    if ( obj && obj.isActive ) {

        obj.timer = setTimeout( obj.animString + ".rotate()", dw_Rotator.resumeDelay );

    }

}



dw_Rotator.setup = function () {

    var rObj, r;

    for (var i=0; arguments[i]; i++) {

        rObj = arguments[i];

        r = new dw_Rotator(rObj);

    }

    dw_Rotator.start();

}