/*******************************************************************
*
* File    : AnimatedFader.js
*
* Created : 2000/05/28
*
* Author  : Roy Whittle  (Roy@Whittle.com) www.Roy.Whittle.com
*
* Purpose : To create fading text descriptions
*
* History
* Date         Version        Description
*
* 2000-05-28	1.0		Initial version. Based on the State Transition
*					Diagram created for animated rollovers I
*					modified the code to fade text.
* 2000-05-29	1.1		I did not follow the STD correctly and introduced
*					a bug that left objects in the ON state.
*					This is now corrected.
* 2000-06-07	1.2		Introduced a start colour so that the script
*					can be used on different backgrounds.
*					Change the var AnimationRunning and FrameInterval
*					so they don't conflict with animate2.js
* 2000-08-09	1.3		Added Gecko ( Netscape 6 Preview Release 1 ) support
*					- Ken workman k.workman@3DASA.com
* 2000-10-15	1.4		Modified to make Netscpe 6 (PR3) more efficient
*					by just changing the color instead of replacing
*					the whole content of the DIV.
***********************************************************************/
/*** Create some global variables ***/
var FadingObject = new Array();
var FadeRunning=false;
var FadeInterval=30;

/*******************************************************************************/
/*** These are the simplest HEX/DEC conversion routines I could come up with ***/
/*** I have seen a lot of fade routines that seem to make this a             ***/
/*** very complex task. I am sure somene else must've had this idea          ***/
/*******************************************************************************/
var hexDigit=new Array("0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F");
function dec2hex(dec)
{
	return(hexDigit[dec>>4]+hexDigit[dec&15]);
}
function hex2dec(hex)
{
	return(parseInt(hex,16))
}
/******************************************************************************************/

/***********************************************************
* Function   : createFaderObject
*
* Parameters : theDiv   - The name of the DIV in which to fade the text
*              numSteps - The number of steps to use in the fade.
*		       startColor - The background colour of the page.
*              
* Description : Creates an object that can hold the current
*               state of the fade animation for a particular DIV
***********************************************************/
function createFaderObject(theDiv, numSteps, startColor)
{
	if(!startColor)
		startColor = "000000";
		
	this.name		= theDiv;
	this.text		= null;
	this.color		= "FFFFFF";
	this.next_text	= null;
	this.next_color	= null;
	this.state		= "OFF";
	this.index		= 0;
	this.steps		= numSteps;
	this.r		= hex2dec(startColor.slice(0,2));
	this.g		= hex2dec(startColor.slice(2,4));
	this.b		= hex2dec(startColor.slice(4,6));
}

/***********************************************************
* Function   : FadingText
*
* Parameters : theDiv   - The name of the DIV in which to fade the text
*              numSteps - The number of steps to use in the fade.
*              
* Description : Library function to be called from the main HTML.
*		        Creates an object that can hold the current
*               state of the fade animation for a particular DIV
***********************************************************/
function FadingText(theDiv, numSteps, startColor)
{
	FadingObject[theDiv] = new createFaderObject(theDiv, numSteps, startColor);
}
/*****************************************************************
* Function    : start_fading
*
* Description : If the FadeAnimation loop is not currently running
*		        then it is started.
*****************************************************************/
function start_fading()
{
	if(!FadeRunning)
		FadeAnimation();
}
/*****************************************************************
* Function    : set_text
*
* Description : In the new W3C DOM model we need only set the text
*			once, after that we can just change the colour
*****************************************************************/
function set_text(f)
{
	if(navigator.appName.indexOf("Netscape") != -1
		&& document.getElementById)
	{
		var theElement = document.getElementById(f.name);
		var newRange   = document.createRange();
		newRange.setStartBefore(theElement);
		var strFrag    = newRange.createContextualFragment(f.text);	

		while (theElement.hasChildNodes())
			theElement.removeChild(theElement.lastChild);
		theElement.appendChild(strFrag);
		theElement.style.color="#"+f.startColor;
	}
}
/*****************************************************************
*
* Function   : getColor
*
* Parameters : f - the fade object for which to calculate the colour.
*
* Description: Calculates the color of the link depending on
*		       how far through the fade we are.
*
*****************************************************************/
function getColor(f)
{
	var r=hex2dec(f.color.slice(0,2));
	var g=hex2dec(f.color.slice(2,4));
	var b=hex2dec(f.color.slice(4,6));

	r2= Math.floor(f.r+(f.index*(r-f.r))/(f.steps) + .5);
	g2= Math.floor(f.g+(f.index*(g-f.g))/(f.steps) + .5);
	b2= Math.floor(f.b+(f.index*(b-f.b))/(f.steps) + .5);

	return("#" + dec2hex(r2) + dec2hex(g2) + dec2hex(b2));
}
/*****************************************************************
*
* Function   : setColor
*
* Parameters : fadeObj   - The TextFader object to set
*
* Description: Gets the color of the text and writes it to
*		       the DIV.
*
*****************************************************************/
function setColor(fadeObj)
{
	var theColor=getColor(fadeObj);
	var str="<FONT COLOR="+ theColor + ">" + fadeObj.text + "</FONT>";
	var theDiv=fadeObj.name;
	
//if IE 4+
	if(document.all)
	{
		document.all[theDiv].innerHTML=str;
	}	
//else if NS 4
	else if(document.layers)
	{
		document.nscontainer.document.layers[theDiv].document.write(str);
		document.nscontainer.document.layers[theDiv].document.close();
	}
//else if NS 6 (supports new DOM, may work in IE5) - see Website Abstraction for more info.
//http://www.wsabstract.com/javatutors/dynamiccontent4.shtml
	else if (document.getElementById)
	{
		theElement = document.getElementById(theDiv);
		theElement.style.color=theColor;
	}
	
}
/*****************************************************************
*
* Function   : fade_up
*
* Parameters : theDiv  - The div in which to display the text
*		       newText - The text to display when faded in
*		       newColor- The color the text will be.
*
* Description: Depending on the current "state" of the fade
*		       this function will determine the new state and
*		       if neccessary, start the fade effect.            
*
*****************************************************************/
function fade_up(theDiv, newText, newColor)
{
	var f=FadingObject[theDiv];

	if(newColor == null)
		newColor="FFFFFF";

	if(f.state == "OFF")
	{
		f.text  = newText;
		f.color = newColor;
		f.state = "FADE_UP";
		set_text(f);
		start_fading();
	}
	else if( f.state == "FADE_UP_DOWN"
		|| f.state == "FADE_DOWN"
		|| f.state == "FADE_DOWN_UP")
	{
		if(newText == f.text)
			f.state = "FADE_UP";
		else
		{
			f.next_text  = newText;
			f.next_color = newColor;
			f.state      = "FADE_DOWN_UP";
		}
	}
}
/*****************************************************************
*
* Function   : fade_down
*
* Parameters : theDiv  - The div in which to display the text
*
* Description: Depending on the current "state" of the fade
*		       this function will determine the new state and
*		       if neccessary, start the fade effect.            
*
*****************************************************************/
function fade_down(theDiv)
{
	var f=FadingObject[theDiv];

	if(f.state=="ON")
	{
		f.state="FADE_DOWN";
		start_fading();
	}
	else if(f.state=="FADE_DOWN_UP")
	{
		f.state="FADE_DOWN";
		f.next_text = null;
	}
	else if(f.state == "FADE_UP")
	{
		f.state="FADE_UP_DOWN";
	}
        f.text  = '<p>Pentru parcurgerea optima si in siguranta a unei pesteri este important sa avem un echipament suplu, usor si durabil care sa ne asigure un minim de confort. Confortul fizic este determinat in primul rand de imbracamintea pe care o folosim........ pentru detalii referitoare echipamentului necesar plasati cursorul mouseului deasupar imaginilor</p>';
f.next_color = '000000';
set_text(f);
setcolor(f);
}
/*******************************************************************
*
* Function    : Animate
*
* Description : This function is based on the Animate function
*		        of animate.js (animated rollovers).
*		        Each fade object has a state. This function
*		        modifies each object and changes its state.
*****************************************************************/
function FadeAnimation()
{
	FadeRunning = false;
	for (var d in FadingObject)
	{
		var f=FadingObject[d];

		if(f.state == "FADE_UP")
		{
			if(f.index < f.steps)
				f.index++;
			else
				f.index = f.steps;
			setColor(f);

			if(f.index == f.steps)
				f.state="ON";
			else
				FadeRunning = true;
		}
		else if(f.state == "FADE_UP_DOWN")
		{
			if(f.index < f.steps)
				f.index++;
			else
				f.index = f.steps;
			setColor(f);

			if(f.index == f.steps)
				f.state="FADE_DOWN";
			FadeRunning = true;
		}
		else if(f.state == "FADE_DOWN")
		{
			if(f.index > 0)
				f.index--;
			else
				f.index = 0;
			setColor(f);

			if(f.index == 0)
				f.state="OFF";
			else
				FadeRunning = true;
		}
		else if(f.state == "FADE_DOWN_UP")
		{
			if(f.index > 0)
				f.index--;
			else
				f.index = 0;
			setColor(f);

			if(f.index == 0)
			{
				f.text      = f.next_text;
				f.color     = f.next_color;
				f.next_text = null;
				f.state     ="FADE_UP";
				set_text(f);
			}
			FadeRunning = true;
		}
	}
	/*** Check to see if we need to animate any more frames. ***/
	if(FadeRunning)
		setTimeout("FadeAnimation()", FadeInterval);

}