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

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

    Copyright 2001-2008 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: Feb 2009 (opera mousewheel)

    printEnabled property added Nov 2008

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



// horizId only needed for horizontal scrolling

function dw_scrollObj(wndoId, lyrId, horizId) {

    var wn = document.getElementById(wndoId);

    this.id = wndoId; dw_scrollObj.col[this.id] = this;

    this.animString = "dw_scrollObj.col." + this.id;

    this.load(lyrId, horizId);

    

    if (wn.addEventListener) {

        wn.addEventListener('DOMMouseScroll', dw_scrollObj.doOnMouseWheel, false);

    } 

    wn.onmousewheel = dw_scrollObj.doOnMouseWheel;

}



// If set true, position scrolling content div's absolute in style sheet (see documentation)

// set false in download file with position absolute set in .load method due to support issues 

// (Too many people remove the specification and then complain that the code doesn't work!)

dw_scrollObj.printEnabled = false;



dw_scrollObj.defaultSpeed = dw_scrollObj.prototype.speed = 100; // default for mouseover or mousedown scrolling

dw_scrollObj.defaultSlideDur = dw_scrollObj.prototype.slideDur = 500; // default duration of glide onclick



dw_scrollObj.isSupported = function () {

    if ( document.getElementById && document.getElementsByTagName 

         && document.addEventListener || document.attachEvent ) {

        return true;

    }

    return false;

}



dw_scrollObj.col = {}; // collect instances



// custom events 

dw_scrollObj.prototype.on_load = function() {} // when dw_scrollObj initialized or new layer loaded

dw_scrollObj.prototype.on_scroll = function() {}

dw_scrollObj.prototype.on_scroll_start = function() {}

dw_scrollObj.prototype.on_scroll_stop = function() {} // when scrolling has ceased (mouseout/up)

dw_scrollObj.prototype.on_scroll_end = function() {} // reached end

dw_scrollObj.prototype.on_update = function() {} // called in updateDims



dw_scrollObj.prototype.on_glidescroll = function() {}

dw_scrollObj.prototype.on_glidescroll_start = function() {}

dw_scrollObj.prototype.on_glidescroll_stop = function() {} // destination (to/by) reached

dw_scrollObj.prototype.on_glidescroll_end = function() {} // reached end



dw_scrollObj.prototype.load = function(lyrId, horizId) {

    var wndo, lyr;

    if (this.lyrId) { // layer currently loaded?

        lyr = document.getElementById(this.lyrId);

        lyr.style.visibility = "hidden";

    }

    this.lyr = lyr = document.getElementById(lyrId); // hold this.lyr?

    if ( !dw_scrollObj.printEnabled ) {

        this.lyr.style.position = 'absolute'; 

    }

    this.lyrId = lyrId; // hold id of currently visible layer

    this.horizId = horizId || null; // hold horizId for update fn

    wndo = document.getElementById(this.id);

    this.y = 0; this.x = 0; this.shiftTo(0,0);

    this.getDims(wndo, lyr); 

    lyr.style.visibility = "visible";

    this.ready = true; this.on_load(); 

}



dw_scrollObj.prototype.shiftTo = function(x, y) {

    if (this.lyr) {

        this.lyr.style.left = (this.x = x) + "px"; 

        this.lyr.style.top = (this.y = y) + "px";

    }

}



dw_scrollObj.prototype.getX = function() { return this.x; }

dw_scrollObj.prototype.getY = function() { return this.y; }



dw_scrollObj.prototype.getDims = function(wndo, lyr) { 

    this.wd = this.horizId? document.getElementById( this.horizId ).offsetWidth: lyr.offsetWidth;

    this.maxX = (this.wd - wndo.offsetWidth > 0)? this.wd - wndo.offsetWidth: 0;

    this.maxY = (lyr.offsetHeight - wndo.offsetHeight > 0)? lyr.offsetHeight - wndo.offsetHeight: 0;

}



dw_scrollObj.prototype.updateDims = function() {

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

    var lyr = document.getElementById( this.lyrId );

    this.getDims(wndo, lyr);

    this.on_update();

}



// for mouseover/mousedown scrolling

dw_scrollObj.prototype.initScrollVals = function(deg, speed) {

    if (!this.ready) return; 

    if (this.timerId) {

        clearInterval(this.timerId); this.timerId = 0;

    }

    this.speed = speed || dw_scrollObj.defaultSpeed;

    this.fx = (deg == 0)? -1: (deg == 180)? 1: 0;

    this.fy = (deg == 90)? 1: (deg == 270)? -1: 0;

    this.endX = (deg == 90 || deg == 270)? this.x: (deg == 0)? -this.maxX: 0; 

    this.endY = (deg == 0 || deg == 180)? this.y: (deg == 90)? 0: -this.maxY;

    this.lyr = document.getElementById(this.lyrId);

    this.lastTime = new Date().getTime();

    this.on_scroll_start(this.x, this.y);  

    this.timerId = setInterval(this.animString + ".scroll()", 10);    

}



dw_scrollObj.prototype.scroll = function() {

    var now = new Date().getTime();

    var d = (now - this.lastTime)/1000 * this.speed;

    if (d > 0) { 

        var x = this.x + Math.round(this.fx * d); var y = this.y + Math.round(this.fy * d);

        if ( ( this.fx == -1 && x > -this.maxX ) || ( this.fx == 1 && x < 0 ) || 

                ( this.fy == -1 && y > -this.maxY ) || ( this.fy == 1 && y < 0 ) ) 

       {

            this.lastTime = now;

            this.shiftTo(x, y);

            this.on_scroll(x, y);

        } else {

            clearInterval(this.timerId); this.timerId = 0;

            this.shiftTo(this.endX, this.endY);

            this.on_scroll(this.endX, this.endY);

            this.on_scroll_end(this.endX, this.endY);

        }

    }

}



// when scrolling has ceased (mouseout/up)

dw_scrollObj.prototype.ceaseScroll = function() {

    if (!this.ready) return;

    if (this.timerId) {

        clearInterval(this.timerId); this.timerId = 0; 

    }

    this.on_scroll_stop(this.x, this.y); 

}



// glide onclick scrolling

dw_scrollObj.prototype.initScrollByVals = function(dx, dy, dur) {

    if ( !this.ready || this.sliding ) return;

    this.startX = this.x; this.startY = this.y;

    this.destX = this.destY = this.distX = this.distY = 0;

    if (dy < 0) {

        this.distY = (this.startY + dy >= -this.maxY)? dy: -(this.startY  + this.maxY);

    } else if (dy > 0) {

        this.distY = (this.startY + dy <= 0)? dy: -this.startY;

    }

    if (dx < 0) {

        this.distX = (this.startX + dx >= -this.maxX)? dx: -(this.startX + this.maxX);

    } else if (dx > 0) {

        this.distX = (this.startX + dx <= 0)? dx: -this.startX;

    }

    this.destX = this.startX + this.distX; this.destY = this.startY + this.distY;

    this.glideScrollPrep(this.destX, this.destY, dur);

}



dw_scrollObj.prototype.initScrollToVals = function(destX, destY, dur) {

    if ( !this.ready || this.sliding ) return;

    this.startX = this.x; this.startY = this.y;

    this.destX = -Math.max( Math.min(destX, this.maxX), 0);

    this.destY = -Math.max( Math.min(destY, this.maxY), 0);

    this.distY = this.destY - this.startY;

    this.distX = this.destX - this.startX;

    this.glideScrollPrep(this.destX, this.destY, dur);

}



dw_scrollObj.prototype.glideScrollPrep = function(destX, destY, dur) {

    this.slideDur = (typeof dur == 'number')? dur: dw_scrollObj.defaultSlideDur;

    this.per = Math.PI/(2 * this.slideDur); this.sliding = true;

    this.lyr = document.getElementById(this.lyrId); 

    this.startTime = new Date().getTime();

    this.timerId = setInterval(this.animString + ".doGlideScroll()",10);

    this.on_glidescroll_start(this.startX, this.startY);

}



dw_scrollObj.prototype.doGlideScroll = function() {

    var elapsed = new Date().getTime() - this.startTime;

    if (elapsed < this.slideDur) {

        var x = this.startX + Math.round( this.distX * Math.sin(this.per*elapsed) );

        var y = this.startY + Math.round( this.distY * Math.sin(this.per*elapsed) );

        this.shiftTo(x, y); 

        this.on_glidescroll(x, y);

    } else {	// if time's up

        clearInterval(this.timerId); this.timerId = 0; this.sliding = false;

        this.shiftTo(this.destX, this.destY);

        this.on_glidescroll(this.destX, this.destY);

        this.on_glidescroll_stop(this.destX, this.destY);

        // end of axis reached ? 

        if ( this.distX && (this.destX == 0 || this.destX == -this.maxX) 

          || this.distY && (this.destY == 0 || this.destY == -this.maxY) ) { 

            this.on_glidescroll_end(this.destX, this.destY);

        } 

    }

}



//  resource: http://adomas.org/javascript-mouse-wheel/

dw_scrollObj.handleMouseWheel = function(id, delta) {

    var wndo = dw_scrollObj.col[id];

    var x = wndo.x;

    var y = wndo.y;

    wndo.on_scroll_start(x,y);

    var ny;

    ny = 12  * delta + y

    ny = (ny < 0 && ny >= -wndo.maxY)? ny: (ny < -wndo.maxY)? -wndo.maxY: 0;

    wndo.shiftTo(x, ny);

    wndo.on_scroll(x, ny);

}



dw_scrollObj.doOnMouseWheel = function(e) {

    var delta = 0;

    if (!e) e = window.event;

    if (e.wheelDelta) { /* IE/Opera. */

        delta = e.wheelDelta/120;

        //if (window.opera) delta = -delta; // not needed as of v 9.2

    } else if (e.detail) { // Mozilla 

        delta = -e.detail/3;

    }

    if (delta) { // > 0 up, < 0 down

        dw_scrollObj.handleMouseWheel(this.id, delta);

    }

    if (e.preventDefault) e.preventDefault();

    e.returnValue = false;

}



dw_scrollObj.GeckoTableBugFix = function() {} // no longer need old bug fix





// Get position of el within layer (oCont) sOff: 'left' or 'top'

// Assumes el is within oCont

function dw_getLayerOffset(el, oCont, sOff) {

    var off = "offset" + sOff.charAt(0).toUpperCase() + sOff.slice(1);

    var val = el[off];

    while ( (el = el.offsetParent) != oCont ) 

        val += el[off];

    var clientOff = off.replace("offset", "client");

    if ( el[clientOff] ) val += el[clientOff];

    return val;

}



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

// Reminder about licensing requirements

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

// OK to remove after purchasing a license or if using on a personal site.

function dw_checkAuth() {

    var loc = window.location.hostname.toLowerCase();

    //var msg = 'A license is required for all but personal use of this code.\n' + 

        'Please adhere to our Terms of Use if you use dyn-web code.';

    if ( !( loc == '' || loc == '127.0.0.1' || loc.indexOf('localhost') != -1 

         || loc.indexOf('192.168.') != -1 || loc.indexOf('dyn-web.com') != -1 ) ) {

        alert(msg);

    }

}

dw_Event.add( window, 'load', dw_checkAuth);

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