/*************************************************************************
  This code is from Dynamic Web Coding at www.dyn-web.com
  Copyright 2001-4 by Sharon Paine 
  See Terms of Use at www.dyn-web.com/bus/terms.html
  regarding conditions under which you may use this code.
  This notice must be retained in the code as is!
*************************************************************************/
/* dw_hoverscroll.js  version date: June 2004 
   mouseover scrolling for dw_scrollObj (in dw_scrollObj.js)  */
dw_scrollObj.stopScroll = function(wnId) {
	if (dw_scrollObjs[wnId]) {
		dw_scrollObjs[wnId].endScroll();
	}
};
// increase speed onmousedown of scroll links
dw_scrollObj.doubleSpeed = function(wnId) {
	if (dw_scrollObjs[wnId]) {
		dw_scrollObjs[wnId].speed *= 2;
	}
};
dw_scrollObj.resetSpeed = function(wnId) {
	if (dw_scrollObjs[wnId]) {
		dw_scrollObjs[wnId].speed /= 2;
	}
};
// algorithms for time-based scrolling and scrolling onmouseover at any angle adapted from youngpup.net
dw_scrollObj.initScroll = function(wnId, deg, sp) {
	if (dw_scrollObjs[wnId]) {
		var cosine, sine;
		if (typeof deg == "string") {
			switch (deg) {
			case "up" :
				deg = 90;
				break;
			case "down" :
				deg = 270;
				break;
			case "left" :
				deg = 180;
				break;
			case "right" :
				deg = 0;
				break;
			default :
				alert("Direction of scroll in mouseover scroll links should be 'up', 'down', 'left', 'right' or number: 0 to 360.");
			}
		}
		deg = deg % 360;
		if (deg % 90 == 0) {
			cosine = (deg == 0) ? -1 : (deg == 180) ? 1 : 0;
			sine = (deg == 90) ? 1 : (deg == 270) ? -1 : 0;
		} else {
			var angle = deg * Math.PI / 180;
			cosine = -Math.cos(angle);
			sine = Math.sin(angle);
		}
		dw_scrollObjs[wnId].fx = cosine / (Math.abs(cosine) + Math.abs(sine));
		dw_scrollObjs[wnId].fy = sine / (Math.abs(cosine) + Math.abs(sine));
		dw_scrollObjs[wnId].endX = (deg == 90 || deg == 270) ? dw_scrollObjs[wnId].x : (deg < 90 || deg > 270) ? -dw_scrollObjs[wnId].maxX : 0;
		dw_scrollObjs[wnId].endY = (deg == 0 || deg == 180) ? dw_scrollObjs[wnId].y : (deg < 180) ? 0 : -dw_scrollObjs[wnId].maxY;
		dw_scrollObjs[wnId].startScroll(sp);
	}
};
// speed (optional) to override default speed (set in dw_scrollObj.speed)
dw_scrollObj.prototype.startScroll = function(speed) {
	if (!this.ready) {
		return;
	}
	if (this.timerId) {
		clearInterval(this.timerId);
	}
	this.speed = speed || dw_scrollObj.speed;
	this.lyr = document.getElementById(this.lyrId);
	this.lastTime = (new Date()).getTime();
	this.on_scroll_start();
	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 + this.fx * d;
		var y = this.y + this.fy * d;
		if (this.fx == 0 || this.fy == 0) {
			// for horizontal or vertical scrolling
			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(this.lyr, x, y);
				this.on_scroll(x, y);
			} else {
				clearInterval(this.timerId);
				this.timerId = 0;
				this.shiftTo(this.lyr, this.endX, this.endY);
				this.on_scroll_end(this.endX, this.endY);
			}
		} else {
			// for scrolling at an angle (stop when reach end on one axis)
			if ((this.fx < 0 && x >= -this.maxX && this.fy < 0 && y >= -this.maxY) || (this.fx > 0 && x <= 0 && this.fy > 0 && y <= 0) || (this.fx < 0 && x >= -this.maxX && this.fy > 0 && y <= 0) || (this.fx > 0 && x <= 0 && this.fy < 0 && y >= -this.maxY)) {
				this.lastTime = now;
				this.shiftTo(this.lyr, x, y);
				this.on_scroll(x, y);
			} else {
				clearInterval(this.timerId);
				this.timerId = 0;
				this.on_scroll_end(this.x, this.y);
			}
		}
	}
};
dw_scrollObj.prototype.endScroll = function() {
	if (!this.ready) {
		return;
	}
	if (this.timerId) {
		clearInterval(this.timerId);
	}
	this.timerId = 0;
	this.lyr = null;
};
dw_scrollObj.prototype.on_scroll = function() {
};
dw_scrollObj.prototype.on_scroll_start = function() {
};
dw_scrollObj.prototype.on_scroll_end = function() {
};