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

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

  Copyright 2003-4 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_lib.js - used with dw_glide.js, dw_glider.js, ...

  version date July 2004 

*/



dynObj.holder = {}; 

// constructor

function dynObj(id,x,y,w,h) {

  var el = dynObj.getElemRef(id);

  if (!el) return;  this.id = id; 

  dynObj.holder[this.id] = this; this.animString = "dynObj.holder." + this.id;

  var px = window.opera? 0: "px";

	this.x = x || 0;	if (x) el.style.left = this.x + px;

	this.y = y || 0;	if (y) el.style.top = this.y + px;

	this.w = w || el.offsetWidth || 0;	this.h = h || el.offsetHeight || 0;

	// if w/h passed, set style width/height

	if (w) el.style.width = w + px; if (h) el.style.height = h + px;

}



dynObj.getElemRef = function(id) { 

  var el = document.getElementById? document.getElementById(id): null;

  return el;

} 



dynObj.getInstance = function(id) {

  var obj = dynObj.holder[id];

  if (!obj) obj = new dynObj(id);

  else if (!obj.el) obj.el = dynObj.getElemRef(id);

  return obj;

}



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

  var el = this.el? this.el: dynObj.getElemRef(this.id)? dynObj.getElemRef(this.id): null;

  if (el) {

    if (x != null) el.style.left = (this.x = x) + "px";

    if (y != null) el.style.top = (this.y = y) + "px";

  }

}



dynObj.prototype.shiftBy = function(x,y) { this.shiftTo(this.x+x, this.y+y); }



dynObj.prototype.show = function() { 

  var el = this.el? this.el: dynObj.getElemRef(this.id)? dynObj.getElemRef(this.id): null;

  if (el) el.style.visibility = "visible"; 

}

dynObj.prototype.hide = function() { 

  var el = this.el? this.el: dynObj.getElemRef(this.id)? dynObj.getElemRef(this.id): null;

  if (el) el.style.visibility = "hidden"; 

}





// for time-based animations

// resources: www.13thparallel.org and www.youngpup.net (accelimation)

var dw_Bezier = {

  B1: function (t) { return t*t*t },

  B2: function (t) { return 3*t*t*(1-t) },

  B3: function (t) { return 3*t*(1-t)*(1-t) },

  B4: function (t) { return (1-t)*(1-t)*(1-t) },

  // returns current value based on percentage of time passed

  getValue: function (percent,startVal,endVal,c1,c2) {

    return endVal * this.B1(percent) + c2 * this.B2(percent) + c1 * this.B3(percent) + startVal * this.B4(percent);

  }

}



// adapted from accelimation.js by Aaron Boodman of www.youngpup.net

dw_Animation = {

  instances: [],

  add: function(fp) {

    this.instances[this.instances.length] = fp;

  	if (this.instances.length == 1) this.timerID = window.setInterval("dw_Animation.control()", 10);

  },

  

  remove: function(fp) {

    for (var i = 0; this.instances[i]; i++) {

  		if (fp == this.instances[i]) {

  			this.instances = this.instances.slice(0,i).concat( this.instances.slice(i+1) );

  			break;

  		}

  	}

  	if (this.instances.length == 0) {

  		window.clearInterval(this.timerID);	this.timerID = null;

  	}

  },

  

  control: function() {

    for (var i = 0; this.instances[i]; i++) {

  		if (typeof this.instances[i] == "function" ) this.instances[i]();

      else eval(this.instances[i]);

    }

  }

}