// Basic Element Animator (14-May-2009)
// by Vic Phillips http://www.vicsjavascripts.org.uk

// To progressively change the Left, Top, Width, Height or Opacity of an element over a specified period of time.
// With the ability to scale the effect time on specified minimum/maximum values
// and with three types of progression 'sin' and 'cos' and liner and an optional 'Bounce'.

// **** Application Notes

// **** The HTML Code
//
// when moving an element the inline or class rule style position of the element should be assigned as
// 'position:relative;' or 'position:absolute;'.
//
// The element would normally be assigned a unique ID name.
//

// **** Executing the Effect(Script)
//
// The effect is executed by an event call to function 'zxcBAnimator('width#',document.getElementById('tst'),10,800,5000,[10,800],'sin');'
// where:
//  parameter 0 = the mode(see Note 2).                                                                     (string)
//  parameter 1 = the unique ID name or element object.                                                     (string or element object)
//  parameter 2 = the start position of the effect.                                                         (digits, for opacity minimum 0, maximum 100)
//  parameter 3 = the finish position of the effect.                                                        (digits, for opacity minimum 0, maximum 100)
//  parameter 4 = (optional) period of time between the start and finish of the effect in milliseconds.     (digits or defaults to 2000 milliSeconds)
//  parameter 5 = (optional) to scale the effect time on a specified minimum/maximum.                        (array, see Note 5)
//                 field 0 the minimum. (digits)
//                 field 1 the maximum. (digits)
//  parameter 6 = (optional) the type of progression, 'sin', 'cos' or 'liner'.                              (string, default = 'liner')
//                 'sin' progression starts fast and ends slow.
//                 'cos' progression starts slow and ends fast.
//
//  Note 1:  The default units(excepting opacity) are 'px'.
//  Note 2:  Examples modes: 'left', 'top', 'width', 'height', 'opacity.
//           For hyphenated modes, the first character after the hyphen must be upper case, all others lower case.
//  Note 3:  To 'toggle' the effect include '#' in parameter 0.
//           The first call will set the toggle parameters.
//           Subsequent calls with '#' in parameter 0 and the same start and finish parameters will 'toggle' the effect.
//  Note 4:  The function may be re-executed with a different set of parameters (start/finish time or period)
//           whenever required, say from an onclick/mouseover/out event.
//           The period parameter will be retained unless re-specified.
//  Note 5: parameter 5 is of particular use when re-calling the effect
//          in mid travel to retain an constant rate of progression.
//  Note 6: parameters 2 and 3 must be different values to execute the script.
//

// **** Advanced Applications
//
//  Calling function 'zxcBAnimator' returns the instance of the script,
//  this may be assigned to a variable and used to access the current value of the effect or to control the effect.
//  alternatively the script instance by elementobject[mode.replace(/\W/g,'')+'oop'];
//  where mode is parameter 0 of the initial call.
//  An array storing the current, start and finish values of the element effect may be accessed
//  from the element [instance].data as fields 0, 1 and 2 respectively where [instance] is the instance of the script.
//
//  Once initialised the effect may be updated by calling function
//  [instance].update([100,200])
//  where:
//   parameter 0 = an array defining the start and finish values.                                            (array)
//                  field[0] =the start position of the effect.   (digits, for opacity minimum 0, maximum 100)
//                  field[0] = the finish position of the effect. (digits, for opacity minimum 0, maximum 100)
//   parameter 1 = (optional) period of time between the start and finish of the effect in milliseconds.     (digits or defaults to 2000 milliSeconds)
//   parameter 2 = (optional) to scale the effect time on a specified minimum/maximum.                        (array, see Note 5)
//                   field 0 the minimum. (digits)
//                   field 1 the maximum. (digits)
//   parameter 3 = (optional) the type of progression, 'sin', 'cos' or 'liner'.                              (string, default = 'liner')
//                  'sin' progression starts fast and ends slow.
//                  'cos' progression starts slow and ends fast.
//
// ** Bounce
//   A 'bounce' effect may be applied by assigning the script instance property 'Bounce' an array
//   defining the 'bounce' properties.
//   e.g.
//   [instance].Bounce=[100,90,4,200];
//   where:
//    field[0] = the 'bounce' maximum.  (digits)
//    field[1] = the 'bounce' minimum.  (digits)
//    field[2] = the number of bounces. (digits)
//    field[3] = the 'bounce' duration. (digits)
//


// **** General
//
// Function names are prefixed with 'zxc' to minimise conflicts with other JavaScripts.
// These characters may be changed to characters of choice using global find and replace.
//
// The Functional Code, about 2.41K with 'bounce' and 'opacity' or 1.97K without is best as an External JavaScript.
//
// Tested with IE7 and Mozilla FireFox on a PC.
//

// **** Functional Code - NO NEED to Change


function zxcBAnimator(mde,obj,srt,fin,ms,scale,curve){
 if (typeof(obj)=='string'){ obj=document.getElementById(obj); }
 if (!obj) return;
 var oop=obj[mde.replace(/\W/g,'')+'oop'];
 if (oop){
  if (oop.srtfin[0]==srt&&oop.srtfin[1]==fin&&mde.match('#')) oop.update([oop.data[0],(oop.srtfin[0]==oop.data[2])?fin:srt],ms,scale,curve);
  else oop.update([srt,fin],ms,scale,curve);
 }
 else oop=obj[mde.replace(/\W/g,'')+'oop']=new zxcBAnimatorOOP(mde,obj,srt,fin,ms,scale,curve);
 return oop;
}

function zxcBAnimatorOOP(mde,obj,srt,fin,ms,scale,curve){
 this.srtfin=[srt,fin];
 this.to=null;
 this.obj=obj;
 this.mde=mde.replace(/\W/g,'');
 this.update([srt,fin],ms,scale,curve);
}

zxcBAnimatorOOP.prototype.update=function(srtfin,ms,scale,curve){
 clearTimeout(this.to);
 this.time=ms||this.time||200;
 this.data=[srtfin[0],srtfin[0],srtfin[1]];
 this.mS=this.time*(!scale?1:Math.abs((srtfin[1]-srtfin[0])/(scale[1]-scale[0])));
 this.ms=this.mS;
 this.curve=(typeof(curve)=='string')?curve.charAt(0).toLowerCase():(this.curve)?this.curve:'x';
 this.inc=Math.PI/(2*this.mS);
 this.srttime=new Date().getTime();
 this.cng();
}

zxcBAnimatorOOP.prototype.cng=function(){
 this.ms=new Date().getTime()-this.srttime;
 this.data[0]=(this.curve=='s')?Math.floor((this.data[2]-this.data[1])*Math.sin(this.inc*this.ms)+this.data[1]):(this.curve=='c')?(this.data[2])-Math.floor((this.data[2]-this.data[1])*Math.cos(this.inc*this.ms)):(this.data[2]-this.data[1])/this.mS*this.ms+this.data[1];
 this.apply();
 if (this.ms<this.mS) this.to=setTimeout(function(oop){return function(){oop.cng();}}(this),10);
 else {
  this.data[0]=this.data[2];
  this.apply();
  if (this.Bounce&&this.Bounce[2]>0) this.bounce();
 }
}

zxcBAnimatorOOP.prototype.apply=function(){
 if (isFinite(this.data[0])){
  if (this.mde!='left'&&this.mde!='top'&&this.data[0]<0) this.data[0]=0;
  if (this.mde!='opacity') this.obj.style[this.mde]=this.data[0]+'px';
  else zxcOpacity(this.obj,this.data[0]);
 }
}

zxcBAnimatorOOP.prototype.bounce=function(){
 if (this.Bounce[2]%2==0)
 this.Bounce[1]+=(this.Bounce[0]-this.Bounce[1])/(this.Bounce[2])
 this.update([this.data[0],this.Bounce[this.Bounce[2]%2==0?1:0]],this.Bounce[3]/this.Bounce[2]);
 this.Bounce[2]--;
}

function zxcOpacity(obj,opc){
 if (opc<0||opc>100) return;
 obj.style.filter='alpha(opacity='+opc+')';
 obj.style.opacity=obj.style.MozOpacity=obj.style.KhtmlOpacity=opc/100-.001;
}