//***********************************************************************************
//         JavaScript HTML DIV scroll bar controler
//
//                                 by mostone@hotmail.com 2005.06.15
//
//          useage:
//                 create DIV scrollbar
//                 scroll directions: scroll up/ down/ left/ right
//          setp 1:
//                   in HTML document, add a div tag and give "id" attribute
//          setp 2:
//                   include this file into your HTML and etc document
//                          use "<script>" tag include src attribute
//          setp 3:
//                   write your script
//                   exmple:
//                        var scrollBarControl = new scrollBar();
//                        scrollBarControl.addBar("myBarID", 100, 100, 50, "down");
//                        scrollBarcontrol.createScrollBars();
//           finally:
//                   save your HTML document and test it.
//
//----------------------------------------------------------------------------------
//         method:
//                 scrollBar()
//                                         scrollBarControl class constrction
//                                                    without parameters
//                 addBar(barID, width, height, interval, direction)
//                                         add user bar define
//                                 parameters:
//                                         barID (Required)              String <DIV ID="xxx"> the id tag
//                                         width (Optional)               Integer that specifies the bar's width
//                                         height (Optional)              Integer that specifies the bar's height
//                                         interval (Optional)             Integer that specifies the number of milliseconds.
//                                         direction (Optional)            String that specifies the scroll direction
//
//***********************************************************************************

var __scrollBarControl = null;

function innerBarProp(barID, width, height, interval, direction)
{
	this.barID = barID;
	this.width = width;
	this.height = height;
	this.interval = interval;
	this.direction = direction;
	this.stopScroll = false;
	this.maxValue = 0;
	this.preValue = 0;
}

function scrollBar()
{
	this.barsArray = new Array();
	//save current object
	__scrollBarControl = this;
}

//////////////////////////////////////////////////////////////////
// add scrollbar to bar list and set properties
// parameters:
//     barID: HTML's tag <DIV>'s id property 
//              (for js access the DIV object)
//     width: define the scrollbar's width
//     height: define the scrollbar's height
//     interval: define the scroll speed 
//               ( scroll up/down per XX millinSecond )
//     direction: scroll direction's defined
//               "up"
//               "down"
//               "left"
//               "right"
//////////////////////////////////////////////////////////////////
scrollBar.prototype.addBar = function(barID, width, height, interval, direction)
{
	//check parameters
	var paraCount = arguments.length;
	if ( paraCount < 1 )
	{
		alert("parameters count incorect!");
		return;
		//throw "parameters count inccorect!";
	}
	
	//width's default value
	if ( typeof( width ) == "undefined" )
	{
		var width = 100;
	}
	
	//height's default value
	if ( typeof( height ) == "undefined" )
	{
		var height = 100;
	}
	
	//interval's default value
	if ( typeof( interval ) == "undefined" )
	{
		var interval = 1000;
	}
	
	//direction's default value
	if ( typeof( direction ) == "undefined" )
	{
		var direction = "up";
	}
	
	//create scrollbar's inner properties
	var barProp = new innerBarProp(barID, width, height, interval, direction);
	var barCount = this.barsArray.length;
	this.barsArray[barCount] = barProp;
}

scrollBar.prototype.createScrollBars = function()
{
	//get bar's count
	var barCount = this.barsArray.length;
	//if no bar add to scrollControl do nothing
	if ( barCount == 0 )
	{
		return;
	}
	
	//init scroll bars
	for ( var i=0; i<barCount; i++ )
	{
		var objBarID = this.barsArray[i].barID;
		//if typeof objBarID is object
		// that's meaning it inited
		//if typeof objBarID is string
		// init that scroll bar
		if ( typeof( objBarID ) == "string" )
		{
			//get scroll <DIV> object
			var objBar = document.getElementById( objBarID );
			if (objBar == null)
			{
				//objBarID is not exist
				if ( document.readyState == "complete" || document.readyState == "loaded" )
				{
					//the objBarID not exists in current document
					//throw "the objBarID is not exists.";
					alert("ScrollBar[" + objBarID + "]: not exist!");
					return;
				}
				else
				{
					//wait for document to load objBarID
					window.setTimeout("__scrollBarControl.createScrollBars()",50);
					//exit processing..........
					//and wait next time callbak
					return;
				}
			}
			
			//update barID
			this.barsArray[i].barID = objBar;
		}
	}
	
	for ( var i=0; i<barCount; i++ )
	{
		this.innerInitBar(i);
	}
}

scrollBar.prototype.innerInitBar = function (index)
{	
	//get properties
	var barID = this.barsArray[index].barID;
	var width = this.barsArray[index].width;
	var height = this.barsArray[index].height;
	var interval = this.barsArray[index].interval;
	var direction = this.barsArray[index].direction;
	var maxValue = 0;
	
	//set scrollBar's properties
	with(barID)
	{
		style.width = width;
		style.height = height;
		noWrap=true;

		switch( direction )
		{
			case "up":
				maxValue = Math.max(scrollHeight, height);
				style.overflowX = "visible";
				style.overflowY = "hidden";
				var barHtml = innerHTML;
				var newHtml = "<table border='0' cellspacing='0' cellpadding='0'>\n";
				newHtml += "  <tr>\n";
				newHtml += "    <td height='" + maxValue + "' valign='top'>\n";
				newHtml += barHtml + "\n";
				newHtml += "    </td>\n";
				newHtml += "  </tr>\n";
				newHtml += "  <tr>\n";
				newHtml += "    <td height='" + maxValue + "' valign='top'>\n";
				newHtml += barHtml + "\n";
				newHtml += "    </td>\n";
				newHtml += "  </tr>\n";
				newHtml += "</table>\n";
				innerHTML = newHtml;
				break;
			case "down":
				maxValue = Math.max(scrollHeight, height);
				style.overflowX = "visible";
				style.overflowY = "hidden";
				var barHtml = innerHTML;
				var newHtml = "<table border='0' cellspacing='0' cellpadding='0'>\n";
				newHtml += "  <tr>\n";
				newHtml += "    <td height='" + maxValue + "' valign='top'>\n";
				newHtml += barHtml + "\n";
				newHtml += "    </td>\n";
				newHtml += "  </tr>\n";
				newHtml += "  <tr>\n";
				newHtml += "    <td height='" + maxValue + "' valign='top'>\n";
				newHtml += barHtml + "\n";
				newHtml += "    </td>\n";
				newHtml += "  </tr>\n";
				newHtml += "</table>\n";
				innerHTML = newHtml;
				scrollTop = maxValue;
				break;
			case "left":
				maxValue = Math.max(scrollWidth, width);
				style.overflowX = "hidden";
				style.overflowY = "visible";
				var barHtml = barID.innerHTML;
				var newHtml = "<table border='0' cellspacing='0' cellpadding='0' width='" + (maxValue * 2 ) + "'>\n";
				newHtml += "  <tr>\n";
				newHtml += "    <td width='" + maxValue + "' valign='top'>\n";
				newHtml += barHtml + "\n";
				newHtml += "    </td>\n";
				newHtml += "    <td width='" + maxValue + "' valign='top'>\n";
				newHtml += barHtml + "\n";
				newHtml += "    </td>\n";
				newHtml += "  </tr>\n";
				newHtml += "</table>\n";
				innerHTML = newHtml;
				break;
			case "right":
				maxValue = Math.max(scrollWidth, width);
				style.overflowX = "hidden";
				style.overflowY = "visible";
				var barHtml = innerHTML;
				var newHtml = "<table border='0' cellspacing='0' cellpadding='0' width='" + (maxValue * 2 ) + "'>\n";
				newHtml += "  <tr>\n";
				newHtml += "    <td width='" + maxValue + "' valign='top'>\n";
				newHtml += barHtml + "\n";
				newHtml += "    </td>\n";
				newHtml += "    <td width='" + maxValue + "' valign='top'>\n";
				newHtml += barHtml + "\n";
				newHtml += "    </td>\n";
				newHtml += "  </tr>\n";
				newHtml += "</table>\n";
				innerHTML = newHtml;
				scrollLeft = maxValue;
				break;
			default:
				//throw "direction is inccorect!";
				alert("ScrollBar[" + id + "]: direction is incorect!");
				return;
		}
		
		//set mouse events
		onmouseover = new Function("__scrollBarControl.mouseEvt(" + index + ",true);");
		onmouseout = new Function("__scrollBarControl.mouseEvt(" + index + ",false);");
		window.setInterval("__scrollBarControl.scroll(" + index + ");",interval);
		
		//save maxValue
		this.barsArray[index].maxValue = maxValue;
	}
}

scrollBar.prototype.mouseEvt = function(index, stop)
{
	this.barsArray[index].stopScroll = stop;
}

scrollBar.prototype.scroll = function(index)
{
	//get properties
	var barID = this.barsArray[index].barID;
	var width = this.barsArray[index].width;
	var height = this.barsArray[index].height;
	var interval = this.barsArray[index].interval;
	var direction = this.barsArray[index].direction;
	var stopScroll = this.barsArray[index].stopScroll;
	var preValue = this.barsArray[index].preValue;
	var maxValue = this.barsArray[index].maxValue;
	
	if ( stopScroll == true ) return;
	
	switch(direction)
	{
		case "up":
				preValue++;
				if ( preValue >= maxValue )
				{
					preValue = 0;
				}
				barID.scrollTop = preValue;
				break;
		case "down":
				preValue--;
				if ( preValue <= 0 )
				{
					preValue = maxValue;
				}
				barID.scrollTop = preValue;
				break;
		case "left":
				preValue++;
				if ( preValue >= maxValue )
				{
					preValue = 0;
				}
				barID.scrollLeft = preValue;
				break;
		case "right":
				preValue--;
				if ( preValue <=0 )
				{
					preValue = maxValue;
				}
				barID.scrollLeft = preValue;
				break;
	}
	this.barsArray[index].preValue = preValue;
}

//=================end of file===========================